TheSamba.com :: View topic - Transmission troubles in Costa Rica. Need help now!

Sat Jul 19, 2014 1:15 pm

Hello all.

We are traveling north in our 1985 1.9l DG carb van. After hearing awful sounds, we stopped in a remote garage to see what was wrong. We have a 5 speed ABN trans and after removing and opening her, we discovered that in the front section the needle bearings were burned and the one under the reverse gear was fully gone. The green plastic spacer was melted to a ropy, compressed mess. It appears that our previous mechanic forgot the circ clip that goes between R and the synchronizer hub. These two surfaces, R and the hub rubbed against eachother generating all the heat that created the problem.

With these issues identified and confirming that all else was well, we ordered the necessary parts. After two weeks of waiting, we now have parts and are doing the reassembly. All is going well, but it is very difficult to tighten the new retaining ring. The mechanic constructed a socket of sorts that fits the retaining ring ok. They can't turn it by hand and are using an impact wrench. Even with this, it is not as tight as it was before (no ring threads are visible). Here is my question:

How do you know when this ring is tight enough? The mechanic argues that the fact that there is axial play in the pinion rod is fine and when he slides it, it is clear that the retaining ring is not compressing main pinion bearing between the two shims.

Is the mechanic right and the retaining ring should be able to be moved around with the pinion shaft or should it be tight and restrict axial play on the pinion shaft?

Your rapid response is most appreciated as he wants to close the case fast.

Many thanks!
Ben

Sat Jul 19, 2014 8:26 pm

Ben

Not entirely certain of which nut you're describing, so here's two:

The 1st gear race must be tightened to 152 ft/lbs to properly preload the pinion bearing

The pinion bearing retaining nut must be tightened to 160 ft/lbs, and peened (or use blue loctite).

Sat Jul 19, 2014 8:27 pm

Ben

Not entirely certain of which nut you're describing, so here's two:

The 1st gear race must be tightened to 152 ft/lbs to properly preload the pinion bearing

The pinion bearing retaining nut must be tightened to 160 ft/lbs, and peened (or use blue loctite).

Sun Jul 20, 2014 12:13 am

Ben,

You mention a "pinion rod" (?) and a "pinion shaft" and a retaining ring. Somewhat confusing. So, is the "lock ring" in question the one Gears shows in his second picture being tightened? That's the pinion bearing and the shaft running through it is the pinion shaft. If that's the part we're discussing then I have some input.

You also mention that it is clear the retaining ring is not compressing the bearing "between the two shims" without explaining what you are observing that leads you to conclude that. First, the S3 shim should be on the trans end of the pinion bearing, and the plain shim on the differential end just under the retaining lock ring. So fix that if necessary. The retaining ring functions to pull the pinion bearing's tapered outer race tightly into the tapered hole in the case.

You also use the word "axial play". That means the shaft can be moved along its length as if you are sliding a piston up and down in its bore. If indeed you can do this and the retaining ring is also moving in and out (moving away from the case and back against it) even though it is pretty tight, then you've got a problem. Big problem.

If you are actually referring to "radial play" where the pinion shaft can move "sideways" or "rock" in the bearing, but the lock ring is NOT moving against the case then you are referring to a bit of play in the bearing itself. That's because the pinion shaft is attached to the bearing's inner race and this is movement from wear of the bearing.

Not trying to confuse you but this is an important distinction. If the outer race is tight in the case (no movement) but the shaft moves a tiny bit because it is tight in the inner race and there is movement between the inner and outer races then this is tolerable. Not perfect because that shows wear. I'm thinking this is the old bearing being reused - yes? So that would be OK to see a bit of movement.

However, if you are saying the larger diameter OUTER race is moving around in the hole in the case its supposed to fit tightly in, then its not a good situation. You made a comment about threads showing. If this is an old bearing and a new lock ring then different amounts of thread would be expected to show. But if its the old lock ring and the old bearing and different amounts of thread are showing then yes something's amiss. Cross threaded lock ring? Not correctly up to torque Gears recommends? Dunno - you didn't mention if these are new, old or a mix of new/old.

Hope this does not make for more confusion, but essentially some radial/rocking movement on a used bearing is OK. You are in a 3rd world environment and may not have a choice. But if the outer race is loose in the case then you have a bigger problem. I tried to explain that in a couple ways.

Also, be sure they have correctly "clocked" the race so they can "stake" the locking ring to prevent it from turning. There are little gaps in the bearing race that need to be in the right place to let someone fit a punch in to stake the ring. They should have premarked the assembly from the other side to do this and may have - dunno. Have a Bentley manual there?

Regards,
Doug

Sun Jul 20, 2014 5:10 am

Hello Doug and Pablo.

First, thank you both for your replies. You were exactly who I wanted to hear from. Your experience is invaluable.

Second, let me clarify for you what is happening. I am referring to the 'retaining ring' that is being tightened in Gears second photo. The pinion bearing is relatively new (20k km). There is no to very little 'radial play.' I am concerned about the 'axial play' where the pinion shaft and bearing can move forwards and backwards in the case, carrying the retaining ring with it. Looking into the differential side of the case, you can see the ring and bearing literally slide forward and backward about 1-2 mm if grabbing the forward end of the pinion shaft and pushing/pulling.

I have tried to explain 3-4 times to the mechanic that this is not right but he refuses to do anything about it. His home made tool for tightening the retaining ring can't get it any tighter and he is convinced that the play is fine. We took a couple hour break eat some food and when I got back he had sealed up the front end, installed the differential and was ready for installation. I argued that I was uncomfortable and he said it was fine. The transmission went back in.

I am now in a position where, if I fight this, we will have to pull the transmission back out. What will happen if the transmission is driven on and the retaining ring is not holding the pinion bearing tightly in the case? What damage might be done? Do I put my foot down and refuse to drive on the transmission as is and demand that it is removed, that we un-peen ('un-clock)' the retaining ring, twist it off and see if it is cross threaded? I want that retaining ring to be on tight and clearly we are not there yet.

Yes, I have a bentley. I ask the mechanic to look at it, but he is reluctant. It's in english but even the images are useful on their own...

Thanks,
Ben

Sun Jul 20, 2014 6:01 am

If the pinion head can be moved back & forth, the bearing bore is wallowed out, and the case is unusable .. unless a new sleeve is shrink fit in and PRECISELY bored by a machinist. The interference fit of the bearing in the bore is supposed to be a minimum of .01mm (.0004"). If you can see it slopping around, I am surprise the R&P is still good.

I'm afraid this mechanic can't help you, and you will not get very far on a transaxle like this. I'd suggest you find a different case. A non-locker side shifter main case from standard 091/1 vanagon will work.

The proper socket must be used to tighten that nut to 160 lbs. I doubt that a fabricated tool will do this. The bracket shown in the photo must be used, or the socket will just slip off when tightening.

Sun Jul 20, 2014 7:20 pm

Bad News.

Our rebuilt 5-speed gearbox failed after 4 km of use. Let me start with why we rebuilt in the first place. This is important as basically the same issue happened after the rebuild.

The observations two weeks ago were:
-while driving on hilly roads, very quickly a strange noise from the transmission develops. shortly thereafter, trans jumps out of 1st gear. decide to go to mechanic and open it up. we find:
-reverse gear had melted via friction against the face of the synchronizer hub.
-consequently the plastic bearing holder inside reverse gear had also melted. Also, the green plastic spacer on the other side of the reverse gear had melted.
-there was a small hairline crack in the moly-coated synchronizer ring that interacts with the reverse gear
-the bearings under first gear had begun to melt a little on the side that is closest to the hot synchronizer hub.

To resolve these issues, we bought parts to replace those that were damaged and waited 2 weeks for them to arrive to Costa Rica. The mechanic reconstructed the reverse and 1st gear components, sealed it up (with the retaining ring not as tight as I wanted it but their home made socket could not get it tighter) and I went for a test drive.

The observations today were
-After 2 km of driving, largely in second gear at low speeds, I could not shift into first and reverse was very difficult to engage. I immediately turned around and headed back to the mechanics in second gear only.
-They played with the selector shaft and linkage for a while, thinking the issue was there, though I demonstrated that 1st and reverse could not be could not be accessed even when manipulating the shaft by hand. After 3 hours of fiddling, I convinced them to open the case and we found big trouble.
-First gear had melted its face against the synchronizer hub.
-The bearing inside first gear had melted completely
-The synchronizer ring that slides between 1st and Reverse had burn/heat marks on the fist gear side.

Now for the big question:

Why are the first and reverse gears burning up via friction against the synchronizer hub?

This has happened twice now and I am afraid to rebuild again. Literally the metal on the face of the gear (reverse or first) is melting away and mushrooming where it touches the synchronizer. The circlips are in place and are in fine shape. The mechanic blames oil circulation, but I don't believe this as all the parts a full of oil and circulating shards up to the front magnet. Is this a consequence of too much axial play in the pinion rod? What is eating my transmission?

Thanks for the help!

Mon Jul 21, 2014 6:59 am

As stated before, your main case is completely worthless to use in a rebuild. It was worn out perhaps 100,000 miles ago. The bore that is wallowed out is the basis for a solidly held pinion, which the entire workings of the transaxle rely on. I would be totally shocked if your R&P are still good.

Your mechanic is not versed in Syncro (or vanagon) transaxle rebuilding. He has neither the correct tools, nor the abilities to do the job properly.

I meant it when I said you would not get very far, utilizing the case described, with obvious pinion head movement. I think you can perhaps install a regular vanagon transaxle in place until you can get a proper rebuild on your syncro ... but I am not the guy to lead you through this. I think the swap is in the archives.

http://www.thesamba.com/vw/forum/viewtopic.php?t=495334&highlight=syncro+trans+swap

Mon Jul 21, 2014 7:07 am

Thanks Gears.
I will try swapping a 4-speed into our 5-speed.
Ben

Mon Jul 21, 2014 7:16 am

ben_in_bus wrote: Thanks Gears.
I will try swapping a 4-speed into our 5-speed.
Ben

If I understand this correctly, you have a 2wd 5 speed gearbox, not a Syncro gearbox, correct? If so, swapping in a 4 speed is not too hard, but the front gearbox mount is different between the two, so make sure that you get that with the 4 speed.

Also, the shift lever, shift rod and box (under the floor in the front) itself is different between a 5 speed and a 4 speed, but you can use the 5 speed shifter.

Mon Jul 21, 2014 7:33 am

Hello Chris.

You are correct. I do not have the Syncro, but the 2wd 5 speed.

This is good news. That the swap is possible. I just need to know the full collection of parts (beyond the transmission) that are necessary to do this right as I am in a very remote location and getting parts here is terribly difficult.

I have looked for information about this but few are converting a 5 to a 4. Do you have a favorite thread that I could read in reverse where someone changed from a 4 to a 5?

Thanks,
Ben

Mon Jul 21, 2014 7:42 am

I'm not aware of any threads on the subject, but I swapped my 4 speed for a 5 speed and can tell you most of the differences.

Besides the gearbox itself, the minimum parts required will be the front gearbox mount from the 4 speed. If you truly want to change the entire van to 4 speed specs, then I would suggest using the entire shift lever, shift lever box, shifter rods and shifter rod mount on the gearbox from a 4 speed van. In other words, plan on replacing all of the shifter components front to rear from the shit lever all the way to the cup on the gearbox. That way you know for sure that all of the components will fit together as intended.

The reason that I suggest using all of those components is that there are some variations in the rear shifter rods, rod mounts and shifter cups that when mixed may not work properly.

Other than that, everything else is a direct bolt in.

Mon Jul 21, 2014 7:47 am

Swapping a wbx 4 speed in for a wbx 5 speed is pretty simple. The tranny nose bracket is all you need to be concerned about. The 5 speed linkage and shifter will work fine with a 4 speed. The 5 speed is a little longer than a 4 speed so the nose bracket is a little shorter on the 5 speed. The short 5 speed nose bracket will bolt to the 4 speed trans but won't quite reach the crossmember when used with the shorter 4 speed trans.

5 speed is a longer tranny, uses a shorter reach nose bracket
4 speed is a shorter tranny, uses a longer reach nose bracket

Mark

ben_in_bus wrote: Hello Chris.

You are correct. I do not have the Syncro, but the 2wd 5 speed.

This is good news. That the swap is possible. I just need to know the full collection of parts (beyond the transmission) that are necessary to do this right as I am in a very remote location and getting parts here is terribly difficult.

I have looked for information about this but few are converting a 5 to a 4. Do you have a favorite thread that I could read in reverse where someone changed from a 4 to a 5?

Thanks,
Ben

Mon Jul 21, 2014 7:57 am

Oh, yes .. that is good news. I somehow have Syncro permanently on the brain ..

Mon Jul 21, 2014 8:16 am

Things keep getting better.

Thanks everyone for your help.

Looking through the Bentley, it is clear that there are two models of the 4 speed transmission, the 091 and the 091/1. The 091 looks like an older version and is significantly different than my 5 speed. Does anyone know when the transition happened? If the 4 speed I am buying is of the 091/1 version, i think a lot of the linkage concerns will go away.

many thanks,
Ben

Mon Jul 21, 2014 8:28 am

The wbx engines only used the 091/1, never the 091.

Vanagon 091 was only aircooled 80-83 and 81/82 diesel.

Mark

ben_in_bus wrote: Things keep getting better.

Thanks everyone for your help.

Looking through the Bentley, it is clear that there are two models of the 4 speed transmission, the 091 and the 091/1. The 091 looks like an older version and is significantly different than my 5 speed. Does anyone know when the transition happened? If the 4 speed I am buying is of the 091/1 version, i think a lot of the linkage concerns will go away.

many thanks,
Ben

Mon Jul 21, 2014 8:30 am

You will want the 091/1 transmission. Obvious differences are the number of studs that attach the transmission bracket to the transmission. The early 091 has 3 studs, the 091/1 has 4. The other obvious difference is how the shift linkage attaches. The early 091 has a pin looking thing that supports the last section of shift rod. The 091/1 has a bracket bolted to the transmission with a plastic bushing. I am linking to the one you don't want.

Early version 091. You can see the studs and the support pin bottom left of picture.

Mon Jul 21, 2014 9:29 am

If you replace a wbx 5 speed with a wbx 4 speed there are no linkage concerns. It will just bolt in and work, assuming you also use the wbx 4 speed nose mount bracket. Here is what it looks like. Below it is a 5 speed bracket next to it so you can see the difference in reach between the 4 speed and 5 speed nose mount brackets. You have a shorter bracket now.

WBX 4 speed nose mount bracket for 091/1

WBX 4 speed nose mount bracket for 091/1

----------------------------------------------------------------------------

On the right is the shorter reach bracket that is for the longer 5 speed tranny

On the right is the shorter reach bracket that is for the longer 5 speed tranny

Mark

ben_in_bus wrote: ..... If the 4 speed I am buying is of the 091/1 version, i think a lot of the linkage concerns will go away.

many thanks,
Ben

Mon Jul 21, 2014 9:56 am

All this help is appreciated!
So glad to have a community backing me up.
Ben

Mon Jul 21, 2014 9:59 am

ben_in_bus wrote: If the 4 speed I am buying is of the 091/1 version, i think a lot of the linkage concerns will go away.

many thanks,
Ben

crazyvwvanman wrote: If you replace a wbx 5 speed with a wbx 4 speed there are no linkage concerns.

Yes, that is exactly what I said up front. The only reason that I mentioned the linkage changes was because ben_in_bus said:

Quote: I just need to know the full collection of parts (beyond the transmission) that are necessary to do this right as I am in a very remote location and getting parts here is terribly difficult.

I have looked for information about this but few are converting a 5 to a 4. Do you have a favorite thread that I could read in reverse where someone changed from a 4 to a 5?

I offered the linkage information simply so that you know EVERYTHING that is different when changing from a 5 speed to a 4 speed, but like I said originally, the 5 speed linkage will work with the 4 speed.

In other words, if you simply want to change the minimum number of parts when swapping from the 5 speed to the 4 speed, then all you need is the gearbox and the front mount. The 5 speed shifter and linkage will work just fine, but the 4 speed shifter is usually (depending on wear) more accurate and feels better than the 5 speed linkage.

If you wanted to swap everything that is related to the 4 speed, then you would want to include the shifter and linkage as well.