411/412 drive train alignment how-to for better shifting

[raygreenwood]

Ok, to start this off I am going to make a statement. I’m on the road this week with a day down time. I used a whole day to get this onto paper. A couple of important qualifications:

This Document will be LONG.
DO NOT SKIP AROUND!
DO NOT GET BORED!
READ IT FIRST AND UNDERSTAND EVERYTHING BEFORE YOU START!

Please understand this warning is not aimed at the most recent poster of this question. I have been posting HUGE amounts of information on these exact problems and the solutions for over 10 years on the Shoptalk Forums and at least several times on the Samba in the short time I have been here.

Each time…it gets studiously ignored by some who need it the most…and I know this is because YOU DON’T KNOW WHAT IM TALKING ABOUT….or you are looking for what simple bolt to turn to fix your problem.

AND ITS NOT YOUR FAULT……..because…………..

only one manual in existence (and it’s the crappiest manual in the world)…has ANY real information about this at all.

Also the likelihood of getting a private aircooled mechanic to do this drivetrain alignment is very low. It’s not hard but the first time will take you 2-3 hours. I can now do all of this in under 30 minutes.

The Chiltons manual, Volkswagen 1970 to 1981 has about 75% complete information on this but it’s very poorly presented and has few if any useful illustrations. I would doubt if 5% have ever read the text sections that present these adjustments because they are mixed in with info for all four aircooled types.

Let’s get started:

What IS the problem here?

The problem has two main parts:

1. The tail cone housing of the 004 transmission is a weak point on its own. It’s easily snapped and broken. I have broken three over the years.

To add to this….the 004 transmission with its full length pinion/main shaft combo is very sensitive to wear and binding if the transmission has any weight and bearing load put on the transmission case. I.e.…..this means you cannot put pressure and load on the transmission case by putting weight on the tail cone because the total weight of engine AND transmission..... is carried buy the upper transmission crossbar. Putting weight or load on the tailcone tries to flex the case in an ARC.

The 004 transmission’s total weight is 100% suspended and held by the center hanger bar over the joint between the transmission and the engine case.
The rear hanger bar and the tail cone bushing have nothing to do with holding the transmission weight. They are torsional movement BUMPERS ONLY.

The problem this causes is fact that the engine and transmission can sometimes move excessively during shifting because of the soft bushings and slack in the tail cone bushing bore. That changes shifter linkage alignment.

VW knew all about this problem.
In the first 1.5 years of 411 models they had a solid four bolt tail cone mount. Yes it kept breakage down, but it caused internal wear issues in transmissions.

This information came from my personal experiences with the same continuing problems with the later power train suspension and shifter linkage as well as from some long conversations with several ex dealer personnel from back in the 1970’s who knew a bit about the earliest cars in the program….and finally from the smattering of cryptic notes about these problems in various manuals. Virtually none of these earliest solid tail cone mount, non-adjustable driveline position cars came to the US. They were 1968 and 1969 only.

The four bolt rear tail cone mount made for the very best shifting and the simplest linkage….but it was hard on the shifter sleeve alignment and caused wear to the main shaft needle bearings….BECAUSE of the flexibility of the three piece magnesium case.

Owners (old and new) of these early four-bolt tail cone/non-adjustable drivetrain cars may not notice or agree that there are problems with this…..but its fact… that VW changed the shift linkage because THEY found that it caused long term issues….three different designs of the linkage and two different designs of the tail cone mount in 3 years are testament to that fact.

The early cars and all of the late cars would also begin to have shift linkage binding as the bonded rubber bushings in the main transmission cross member over the bell housing began to wear out….causing a change in transmission alignment and putting tension on the shift rod coupling.

The first major change in the shift linkage was done just to combat this problem in August of 1969. It was changed again to the final design in April of 1970.

2. Because of this weakness of the case being flexible and the tail cone fragile….VW…in ALL of the post April 1970 type 4 cars, regardless of which mount type or linkage you use…..had a sophisticated alignment procedure for the entire drivetrain.

This was compounded on the later models from April 1970 an onward. These cars used a floating ball stud and slip joint coupling. It made for virtually no shifter rattling/movement in the cabin (also part of why VW wanted to fix these problems)…..but on rough pavement and at high torque shift points….this “slip joint” would over or under extend and cause an increase or decrease in the shifter ball stud arc of rotation when shifting from 2nd to 3rd or downshifting the other direction.

The problems with these late model linkage cars was further compounded as noted above as other items in the linkage wore out……or and this is most common…..as transmissions are changed out and as engines are removed….by personnel other than dealer staff with the proper drivetrain alignment methods at hand……the alignment would put tension on the linkage and change the angles of the parts.

This is all three of the shift couplings laid out together. This is NOT the complete shift linkage….just the fore and aft linkage couplings.

This detail shows the very earliest 1968/69 linkage. It looks just like type 1 but required a solid rear cross member mount for the transmission tail cone very similar to the bus.

This shows both of the later shift rod arrangements. The straight through one with the cylindrical coupling parts # 24 and shaft # 21a are the April 1970 model parts. They still had problems with driveline realignment and putting tension on the shift coupling….which wore out other parts of the linkage.

All of this so far was just for parts ID purposes. This is the meat and potatoes:

There are three main segments to the shift linkage and engine alignment and several “given conditions”.

First the given conditions:

1. Your rear hanger bar center rubber mounts must be in excellent condition. No torn or permanently crushed or greasy/oily parts allowed or you will NOT be successful.

2. Your shifter gate adjustment must be done properly as per the Haynes manual pages 109-111. This is not horribly important YET but it must be close before you begin. You will do it again when you are done with everything else.

3. Your front shift rod bushing mush be in good condition. Ideally you should just replace it before starting it’s about $4

4. The plastic ball cup in the shift rod must be in good condition….not missing or heavily worn. Its part # is 411 711 165 A. If you can’t find one, a nylon sleeve bushing from McMaster Carr can be used.

5. The large plastic “dish/plug” that the shift rod passes through at the rear end of the chassis tunnel MUST be in place and installed correctly with the outlet hole closest to 12:00 position. The hole for the shift rod should not show more than about 1.5mm oval wearing of the plastic hole that the shift rod passes through.

If you cannot manage ALL of these items…please stop reading now as this document will not help you at all. It will just be a lot of work and a mess. FIX THESE ITEMS FIRST!

Linkage Segment #1:

The front shift rod component (the rod from the shifter to the rear coupling)….must be held exactly parallel to the chassis tunnel floor. That means it cannot pivot either fore and aft or side to side. It MUST only be able to slide directly fore and aft and rotate around its center axis.

This alignment is handled by the front plastic bushing forward of the shifter….and that round plastic body tunnel plug in the rear. The rear body tunnel plug/disc is critical. It has a square knob at the 6:00 position that goes into a key slot in the body tunnel opening to make sure it’s installed in the exact location.

This plastic disc/plug….is the rear bushing for holding the rod travel in one plane and not allowing any X and Y movement.

The body tunnel plug/bushing is item # 28 in this picture

If the tunnel plug/plate is cracked, heavily worn or missing…..the tube section of the slip joint in this picture slips downward on the ball. The tube section is attached to the forward shift rod and the ball stud on the right is attached to the transmission “hockey stick”/shift rod.

SERIOUS NOTE: In this picture, look to the left and notice that the plastic Tunnel Disc is MISSING…and in the picture the tubular section of the joint is far too low on the ball stud. The car in the Haynes manual will grind going into every gear every other time. This is the importance of this tunnel plug/bushing disc.

What does this cause?

That ball stud and its attached shift rod is pulled forward when you are selecting 2nd and 4th gears and is pushed backward when you are selecting 1st and 3rd gears.

It also pivots from side to side turning the hockey stick/selector rod in an ARC…when you are moving from a gear in the 1st and 2nd plane and into a gear in the 3rd and 4th plane.

IF THE TUBE COUPLER SLIPS UP OR DOWN ON THE BALL STUD IT INCREASES OR DECREASES THE ROTATION OF THAT ARC TO THE LEFT OR RIGHT BY QUITE A FEW DEGREES. THIS CAUSES INCOMPLETE MOVEMENT OF THE SELECTOR RODS BETWEEN THE SHIFT FORKS….CAUSING MORE THAN ONE FORK TO TRY TO MOVE AT ONE TIME….CAUSING BINDING OR ROUGH SHIFTING….AND LOTS OF WEAR TO THE SHIFT FORKS AND SLEEVES.

The front rod bushing and the rear tunnel cap bushing prevent the forward shift rod from dropping out of plane and the next section of this controls the transmission and ball stud position to keep it from rising or falling within the tube coupling.

RECAP: shift linkage Section one is the fore and aft shift rod bushings (#1 and its snap ring #2 and #18 in the diagram) and the nylon ball cup under the shifter (#14).


Shift linkage Section #2:

The 2nd section is the shift rod coupling unit itself. It must be tightly gripped on the shaft(s) and safety wired on. It uses two 8mm pointed end grub screws. The coupler sleeve from the forward side must not be bent or crushed or misshapen in any way. The ball stud should have a nylon ball cap and a rubber bumper O-ring around the middle groove on it.

Items that cause these two parts to malfunction are a worn or bent tube coupling…usually from owners getting poor shifting and beating on this part. If you look inside of the tube coupler and it has heavy wear indentations in it…..if you can measure how deep they are you can gently squeeze the sides of the tube coupler to bring it back into just exact contact with the ball stud.

The tube coupler is “squarish”. The fore and aft sides and the left and aft sides of the coupler should make gentle contact with the rubber O-ring around the mid-section of the ball stud.

The ball stud is item #25 in the picture and the O-ring is item #26.
Next point with that in mind, typically the rubber O-ring around the mid-section gets rotted by grease and grime. You can replace it with a flat washer cut from rubber inner tube if you cannot find an O-ring that fits into the groove.

NOTE: If you have the very early or April 1970 on, as long as your shift coupler and forward segment bushings are intact…you have nothing to worry about in segment #2.


Shift linkage Segment #3:

Drive train and transmission alignment….MOST IMPORTANT FOR ALL TYPES after April 1970

The earliest 411’s had only rudimentary adjusting ability. Though this would help you…I don’t know what adjustments you could do.

VW put in plenty of adjusters for this. Let me outline them for you. From most forward to the rear of the car.

This are what we will be calling the upper transmission support cross member. This carries 90-100% of the weight load of the engine and transmission. Notice part # 24.
These shims are on both sides, about 2-4 per side. They adjust the up and down level position of the drive train and the centering of the tailcone bushing in the socket in the rear cross member.

Notice part # 26….the bolt and the slotted holes it fits into in part #25. This allows you …along with the rear hanger bar outer support brackets (we will get to in a moment) to slide the whole drivetrain package to the left or right by a small amount.

Notice vertical bolt #30 (two of them one each side)and vertical bolts #18 (four of them two each side) Loosening these while working on the rear hanger bar mounts allow a small amount of fore and aft driveline movement without putting side load on the rubber hanger bushings

This is the rear hanger bar diagram. Notice part #14. This bracket bolts into the body at each end. Notice that it has fore and aft slotted holes. The nuts that this bracket bolts into are captive in cages in the body.
The slots in the bracket allow fore and aft adjustment of the entire drivetrain package along with loosening the bolts mentioned in the previous diagram. The captive nuts also allow these plates to slide any direction for side to side fine centering adjustment as well.

Notice the single vertical stud attached to part #14 and the two 8mm nuts part #’s 15. This vertical stud has the sole responsibility of “tilting” the entire drivetrain…pivoting it about the center transmission hanger bar. This is so you can make fine leveling alignment to the attitude of the tailcone bushing and shift rod.

Notice part #’s 16 and 6. These are two horizontal 8mm bolts and their locking plates. Their purpose is to do the actual high strength weight holding and locking of the vertical adjustment to the rear hanger bar. They are in oval holes. There are two at each end of the bar. The vertical stud does the adjusting, the horizontal studs do the holding.

This is a detail shot from below the car of the rear hanger bar mount adjustments. At the top right of the drawing you can see the 13mm head of one of the vertical 8mm bolts that are in slots on the plate that lock into captive nuts on the chassis.

In the left side of the image is the single vertical 8mm stud with the 8mm locknut and lock washer above, and the 8mm adjusting nut and lock washer below. In the center you can see the two horizontal 8mm holding bolts in the top of their oval slots.

NOTE: The horizontal holding bolts MUST always be set to the top of their oval slots at the start of the alignment operation. This is so it affords maximum downward adjusting to affect tilt up of the tail cone bushing and overall leveling of the engine and transmission package. If it is needed to go up HIGHER than the top of the adjusting slots allow……it means that the SHIMS…part #24 two drawings back…..are of incorrect thickness. There is a section for that coming up.

Starting from the front of the Transmission at the suspension cross member:

1. The transmission tailcone bumper: This is designed to NOT actually make contact with any of the sides of the socket/hole in the cross member. It is designed to only make contact with any wall in the hole to absorb MILD and temporary torsional movement during acceleration, bumps and shifting.

IF THE TAIL CONE BUMPER MAKES WALL CONTACT IN THE CROSSMEMBER SOCKET IT WILL CAUSE SHIFTING PROBLEMS BECAUSE IT WILL CHANGE THE TRANSMISSION SHIFT ROD ANGLE AT THE BALL STUD.

THIS BUMPER/BUSHING RELATIONSHIP IS AFFECTED BY EVERYTHING ELSE IN THIS DOCUMENT.

Anything that changes the angle of the tail cone and shift rod will cause contact of this bushing to the socket wall in the rear suspension cross member and cause misalignment of the ball stud in the shift coupler.

XXXXX This bumper has a specific adjustment see the text:XXXXXX

The bumper is the curved shapes top and bottom. The tube in the center is the metal tube that the bushing is wrapped around. The gauge bar is touching the metal tube. It is the metal support tube for the bushing you are aligning in the bore in the cross member. Center that tube and the bushing will be centered as well.

Note the text that explains what is going to be done. So by centered…they mean slightly closer to the bottom of the tube by 2mm.

This is one of the few if not only, technical notes anywhere about drivetrain alignment on these cars. To make sure you get the basic idea of all that is offered on this alignment I am going to repost the above text in order with all of the text before and after it.

Initial warning about not loosening the outer rear hanger bar mounts or the upper transmission carrier bushings while pulling the drivetrain

This you have already seen

Read this one carefully. It’s the gist of all of this

Good technical solution: Since the rubber tailcone bumpers are nearly unobtanium, Measure the socket/bore in the suspension cross member. Cut up a tire inner tube into a strip to the width of the original rubber bushing.

Wrap the rubber around the bushing support tube until it is the correct diameter. Cut to length. Unwrap the rubber strip and apply a smooth, thin layer of contact cement on the rubber and wrap it tightly and tape it until it’s dry. This works very well.

Better technical solution: You can overwrap this bushing to a larger diameter to just slide in and touch the walls of the socket in the cross member. This makes for constant perfect alignment of the ball stud of the coupler and the rubber is soft enough to be a good torsional absorber. I use this. It shifts much smoother.

BUT……TO DO THIS "BETTER MODIFICATION"….YOU NEED TO APPLY 2MM OF EXTRA RUBBER TO THE TOP SIDE OF THE BUSHING SUPPORT TUBE BEFORE YOU WRAP IT SO IT WILL BE POSITIONED PROPERLY IN THE BORE (REMEMBER 12MM TOP AND 10MM BOTTOM)……..AND THE REST OF THE DRIVETRAIN ADJUSTMENTS AND THE QUALITY OF YOUR BUSHINGS MUST BE PERFECT!


How to adjust your drivetrain position step-by-step: Please pay attention to the following Pre-start notes:

NOTE 1: disconnect your battery NOW or you will short out the starter while adjusting the transmission hanger bar.

NOTE 2: The car should be jacked up with at least the rear wheels off the ground so you can move freely underneath. It is better if the front is jacked up partially as well so you can move easily forward of the rear cross member.

NOTE 3: You need to make sure that the steel tube and plate assembly that is the tailcone bushing support tube is properly bolted onto the transmission. There should be no washers between the carrier plate for this part and the transmission case. The nuts should be tight and the oblong pointy section faces the left side of the car.

NOTE 4: Per the diagram, make note by removing one nut from one of the 8mm horizontal bolts at each end of your rear hanger bar….and that the horizontal bolts are at the tops of their oval holes as per the earlier diagram. Also make sure there is a locking nut above the bar on the 8mm vertical stud.

NOTE 5: See this diagram and photo. What they are speaking of is that the rear hanger bar must be centered between the engine case and the fan housing before you start.
If it’s not, it’s possible that the end support plates of the rear hanger bar have been played with and are at one extreme or another of their adjustment range. Check them from the inside of the engine compartment and correct them if need be. It can also signal that the center bushings are twisted or in bad shape.

SIDE NOTE: A lot of these sketches are crude but should get the point across. Apologies.

THIS IS IMPORTANT….it is from this plate and bushing tube assembly in the above diagram that all alignment measurements are judged/measured. It must be on as centered and correct as possible.

1. Looking from underneath the rear trailing arm cross member you want to make sure that the plate that is bolted to the transmission is NOT touching the steel lip around the bore opening in the cross member

2. You want to make sure that the gap between the bushing plate and lip around the bore about .080”” minimum to .125”” maximum. This must be fairly exact because this is about all the fore and aft adjusting play you have in the shift gate plate under the shifter.
If the gap is not correct……CONTINUE TO THE NEXT STEP

3. This is the area above in the drawing where we will be working. Take a 13mm short socket and ratchet and several socket extension bars. You want about 18” minimum to 24” of extension bar.
With this you will lay on your back under the bell housing of the transmission and with the socket and extensions vertical….loosen the two vertical bolts on each one of the bonded rubber bushing mounts on each side of the transmission hanger bar. Loosen then one turn only. Make sure no shims fall out from between the chassis and the hanger bar.

Then loosen the large 17mm vertical bolt at each end of the hanger bar about 1 turn each maximum.

4. Proceed to the rear of the car to the rear engine hanger bar. At each end of the hanger bar the plate that attaches the hanger bar to the chassis has TWO vertical 13mm bolt HEADS showing on each plate on each side, fore and aft of the hanger bar. These bolts are 8mm
Spray some penetrating oil on them. With a long extension bar and the ratchet, loosen each one of the four 8mm bolts about 1 complete turn.

NOTE 1: DO NOT loosen the nut on the 13mm vertical stud at each end of the hanger bar or the two horizontal 8mm bolts with the safety locking plates on them

NOTE 2: The entire driveline is now loose. You can shove the engine and transmission assembly forward by pushing on the rear hanger bar with your feet out near the ends or you may pull it backward by pulling on the same spots in the hanger bar.

NOTE 3: You only need to move the drivetrain a little bit. I usually place a bar of steel shim of .080” thickness between the lower edge of the tailcone bushing plate and the rear cross member so that it has not only a stop but a way to keep the plate parallel to the cross member.

5. Inspect the tailcone bushing carrier plate relationship to the rear suspension cross member. If the GAP between the plate and cross member is now correct….but the plate is CROOKED (like in the sketch above) meaning not parallel to the cross member….GO TO THE NEXT STEP

6. Place the .080” steel shim back in the gap between the tail cone bushing plate and rear cross member and return to the rear of the car.

If the gap between the bushing plate and cross member is larger on the left side you will be working on the left outer side rear hanger bar mount. If it’s bigger on the right you will be working on the right outer rear hanger bar mount.
With a rubber mallet or your foot, working on the side you need to be on….push the rear hanger bar directly toward the hanger bar mount on the other side of the car. You are pushing sideways….not forward or backward.

This pivots the drive train around the center transmission hanger and makes the forward tailcone mount angle to the suspension cross member change.

NOTE: You should have noticed by now that both of these adjustments are moving the outer hanger bar plates against the body. There are captive nuts in welded cages on the body that are just for this.
If you are not getting any movement, either the nuts are rusted to the chassis or more commonly they are packed with mud and dirt. You may need to stop, put a jack under the center of the rear hanger bar…remove all four 13mm bolts so you can access the captive nuts (you can see them inside of the engine compartment) and clean them out so they move.

7. Repeat the adjustment above until the gap between the tailcone bushing plate and the rear suspension cross member is correct and parallel.

8. Hand tighten the four vertical bolts on the transmission cross member. Do not torque them yet. Take the slack out of them and make sure they are snug. Do the same for the four vertical 8mm bolts at the rear hanger bar end mounts and the 17mm vertical bolts at each end of the hanger bar.

9. Stop at this point and move to the forward side of the rear suspension cross member. Take your feeler gauges and a flashlight and a mirror and check the position of the rear tailcone bushing mount tube.

Normally it will be in good adjustment at this point from side to side but incorrect on the top and bottom sides. Do not worry about the top and bottom sides yet.

10. If the tail cone bushing tube is not centered from side to side but the bushing plate is parallel to the suspension cross member, the entire drive train package must be moved sideways. To do this……NEXT STEP

NOTE: you can help verify this condition by looking at the relationship of the engine sheet metal to the surrounding body tin. It will exaggerate the amount that the drive line is off and show large gaps around the sheet metal.

11. Move to the center transmission cross member. At each end of it, slightly above the rubber mounts and outboard of them is a horizontal bolt in a slot. Loosen both of these bolts bout 1.5 turns.

Move to the rear of the car to the outer rear hanger bar support plates and loosen the two vertical 8mm bolts on the fore and aft end of each plate.
Move back to the centerline joint where the transmission joins to the engine case. Shove in the direction you require to move with your foot…gently, alternating with checks of the tailcone bushing to make sure it is centered side to side in the cross member bore.

12. When the tailcone bushing support tube is centered from side to side and the support plate is parallel to the rear cross member, tighten the transmission hanger vertical bolts, alternating from side to side until just snug. Do the same for the outer rear hanger bar supports.

Recheck that the tailcone bushing support tube is still centered side to side in the bore and the support plate is still parallel to the cross member.

13. Now measure the vertical position of the tailcone support tube in the bore of the rear cross member.

CORRECTIVE SCENARIO #1: the Tailcone bushing support tube is too low in the bore

1. If tailcone bushing support tube is closer to the bottom of the cross member bore…the 6:00 position…see if it’s tight in the bore. To do this, grasp the tailcone bushing support plate and wiggle it with your hand. With not much pressure the entire tail of the transmission should flex in all directions about 1/8” to 3/16” max. If it feels tight…..NEXT STEP

2. Move to the rear of the car. Remove the locking plates from the two horizontal 8mm bolts at each end of the rear hanger bar. Remove the nut from only one bolt at each end of the bar so you can observe the position of the bolt in the oval slot. It should be at the top of the slot.

3. Loosen the LOWER 13mm nut on the vertical stud at each end of the bar….the same amount for the nut on each side of the rear hanger.

NOTE: you will notice that every bit of loosening of the 13mm nut on the vertical studs causes the rear engine hanger bar to drop downward. You can see this by watching the 8mm horizontal bolts in their slots. They will move downward.
Do not loosen more than one turn on each side before you return to the tailcone support tube to measure its vertical position in the bore.

NOTE: What is happening is that as the rear hanger is dropping, the driveline package is pivoting about the center transmission hanger bar and lifting the tailcone bushing support in the bore.

NOTE: If you reach proper vertical adjustment of the tailcone bushing support tube in the bore before the four horizontal bolts in the rear hanger bar have passed 2/3 the length of their slots in the downward direction, you are fine.

Verify that the tailcone bushing support plate is still parallel to the suspension cross member and is level from side to side. If it’s not level, adjust it with the nut on the vertical 8mm stud on the end of the rear hanger bar that will lift the correct side to make the plate parallel to the rear cross member.

4. Move the top 8mm locknut on the vertical 8mm studs at the ends of the hanger bars downward and tighten them. This holds your adjustment in place
Recheck your tailcone bushing tube centering measurement and then tighten the four horizontal bolts on the rear hanger bar again.
Make sure the tailcone of the transmission now moves freely about 1/8” in each direction with very little force.

IMPORTANT NOTE! At this point you want to get a flashlight and look at the tailcone bushing support plate from either side of the car. If you have done all of the above correctly, the support pate should be parallel to the cross member and the welded on bushing support tube should be centered in the bore in the rear cross member.

NOW….make sure there is no vertical or horizontal tilt to that plate when looking at it from the side. You can also measure the gap if need be. Usually if the steel bushing support tube is centered correctly and the support plate is parallel to the cross member this will not happen.

When it does happen the gap at the top of the support plate will usually be less than the bottom. This means that the center transmission support hanger is too close to the chassis….so…NEXT STEP

IMPORTANT CORRECTIVE ADJUSTMENT! With the above problem you want to move to the center transmission hanger and get your ratchet, 13mm short socket and 24” extension bars.

Loosen the four vertical mounting bolts on each side of the bonded rubber bushings EQUALLY to keep the drive train level from side to side….½ turn at a time ONLY. Each ½ turn of loosening, stop and inspect the tailcone bushing support plate to see if the tilt is correcting itself.

When the tilt of the bushing support plate is correct, you will need to use feeler gauges to find out how much gap is between the chassis mount bar over the center hanger bar bushings. You should also find that there are between 2 and 4 plate shims under each one already.

These are pretty standard shims and are available from Saab dealers as they were used on the 900, or you can make them or go to any chassis alignment shop to get them. Pull one of yours out and look at it and take it with you. Just mark which side of teh car it came out of.

Loosen the bolts a little more, slip in the shims you need and tighten the bolts. Recheck the tilt of the tailcone bushing support plate.

5. Now recheck the vertical position of the tailcone bushing support tube. You will find it is off and will require another small adjustment of the vertical 8mm stud and the two horizontal bolts at each end of the rear hanger bar.
This adjustment should now require that the adjustment is moving upward and the horizontal bolts are moving upward in their slots.

SCENARIO #2: The tailcone support tube is too high in the bore. The tailcone bushing support plate is vertical and not tilted. This signals that the whole drivetrain unit is simply too high t the center transmission hanger bar.

1. Check that the rear hanger bar center bonded bushings are not crushed

2. Check that the horizontal end bolts in the rear hanger are at the top of their oval holes.

IMPORTANT NOTE: If they are….adjust the vertical 8mm stud to MOVE them to the center of the oval holes. This will make the tailcone support tube adjustment worse for the moment but is in preparation for the next adjustment

NOTE: if these last two items check out….

3. Move to the center transmission hanger bar with your short 13mmm socket, ratchet and 24” extension. Loosen the four vertical 8mm bolts ½ turn at a time, equally from side to side.

4. Stop after each loosening sequence and inspect the tailcone bushing support tube in the bore.

5. Repeat this until the tailcone support bushing tube is in the proper vertical location in the rear suspension cross member bore.

6. Measure the gap between the chassis bar and the tops of the bonded rubber transmission cross member mounts with feeler gauges. Obtain correct shims to put in and tighten the bolts.

7. Recheck the tilt of the tailcone bushing support plate again. If the vertical tilt is now off…which it should be…..

You can now adjust the vertical tilt of the tailcone support plate by adjusting the 8mm nuts on the vertical stud at each end of the rear hanger bar. This is why we moved the adjustment to leave the horizontal bolts in the middle of their oval holes so we would have room to adjust for this after we reshimmed the transmission hanger bar.

You should have correct drivetrain adjustment now. You may need to make some small tweaks on individual vehicles but this is how it’s done. Torque all bolts and make sure everything has a fresh lock washer because these parts will come loose.

Check that your shift coupler tube has a close fit to the ball stud and repeat the Haynes manual shifter adjustment.

It should shift much better …but if it occasionally hangs up from 1-2 or 3-4 gear to another it is usually because of this:

The shifter forks have some wear already. You can figure out which direction the forks are moving not far enough……and slightly dish the shift coupler tube to push the ball in that direction by about a millimeter. It can also be too much gap between the ball stud (fatter O-ring) or a ball stub that is tilted or bent of one that is not tight enough on the shaft.

If it hangs up going from 2 to 3 or downshifting from the 3-4 plane to the 1-2 plane it is usually some small difference in ball stud arc or slack between forks and shift collars/sleeves.

You can fix this by finding or making a spare ball stud….and cutting the top off of one and drilling into both the head and shaft and installing an 8mm stud and locknut. This makes an adjustable length stud. By increasing or decreasing the ball stud length you shorten or lengthen the arc that it turns….making it move farther inside the transmission.

If it’s only a very small amount….you can also make the hole in the tunnel bushing plate that supports the shift rod…oval….and install an adjusting ring with a lock screw….to move the shift coupler tube higher or lower o the ball stud. I have not done this mod yet but I have simulated it with a block and a clamp so it will work.

One of the most critical problems with all of these adjustments are the center rear hanger bar bushings. Most of the replacements are either too soft or too hard. The too soft ones are the big problem with adjusting. As they wear and move they change the adjustment. The too hard ones just don’t live long and you have to repeat these adjustments every time you replace any bushings. The center transmission bushings have the same issue.

Ray

[bradself]

Uber should make this a sticky

[Lars S]

Ray, we are totally impressed of this documentation, many thanks!

Current and future Type4 owners will definitely appreciate your work, thanks again!


/Lars S
_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold

[raygreenwood]

[EverettB]

[raygreenwood]

[bradself]

Ray, this may be a stupid question, however: auto trans cars align the same way? Obviously there's no shifting difficulties but I imagine there are other disadvantages to having the drivetrain in cockeyed. Thanks!

[raygreenwood]

[Lars S]

Thanks to Rays writeup I came to check the rear body tunnel plug/disc on my 412 and yes it had quite some play. I guess finding new plugs is impossible.
I managed to put a zip tie around the three lips who supports the rod and tightened a bit but not to much and after installing the play is wery much reduced.

But also the plug itself is not wery tight fixed in the tunnel hole so Im thinking of a way to fix it in its hole...

/Lars S

_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold

[raygreenwood]

[Lars S]

The plug is from a -73 and it is is all fat on the outer side.

Yes it snaps in hard in the hole but it has an axial play of about 1.5mm so it can wiggle a bit.
I just put a thin rubber O-ring in the space between the plug and the hole (where the red line is in the image) so it now sits much better.

/Lars S
_________________
Porsche 914 -72, Bahia Red daily driver
VW411 2-d -70, White, sold
VW412 4-d, -73, Gold Metallic, daily driver
Suzuki T500, -69, Candy Gold, sold
Suzuki K50, -77, Black, daily driver
BMW R69S -69, White, sold
Husqvarna 118cc, -47, Black, Sold