Down, Down, Down

[jberger]

Hi all,
This is starting to get me down. A little under a year ago I completed the build up of my new 2.0 for a 79 cali model. Installed and broke in with no problems. A short time later while going down the highway the shifter started to rattle, after I had been at speed for several minutes. A little pressure on the shift lever and the rattle went away. I then replaced the shift rod bushings and coupler. The rattle then became more pronounced. I began hearing it in 2nd gear under load going up a hill, 1st and 3rd were ok. So I figure the tranny is going, better get a new one, or better yet my spare with 30,000 less miles on it. So I freshened my spare up with new seals and hockey stick end bushing and threw it in. Took it for a ride around the neighborhood and thought "this one sounds better, only a little gear whine". The next day the gear whine turns into growling in 2nd, 3rd and 4th. Oh well, looks like this one is more tired than the last. So I start shopping for a new tranny. There was a 75 down the road that had a for sale sign in it for quite some time. I knew it had a rebuilt tranny; 5-rib (silent on the test drive). The kid who owned it wanted way too much for it, so there it sat until I had some cash in my pocket and made him an offer he couldn't refuse. The 75 goes back to my place and the next day it is back on the street with the original tranny out of my 79 installed. A couple weeks go by and I was able to install the 75 tranny into my 79. Take it out for a spin and everything is beautiful, quite as a mouse, smooth shifting, etc, etc... Took a shower and then its off to the in-laws with the fam. Take off up the hill and BAM, I hear a slight growl. My heart sinks . The growl grows in second, third and is a little more quiet in 4th. Let me clarify by stating that the noise appears at the same RPM range in all gears, about 3500-4000, very little noise at low RPM in each gear and goes away completely above 62mph in 4th. Coming home from the in-laws the clutch seamed to loose its adjustment, as it was grabbing right off the floor and I was having a tough time getting into 1st and 2nd from a stop. I got underneath it in the Safeway parking lot and adjusted to within spec. Start driving again and the noise is gone. Closer to home the clutch starts to grab close to the floor again and the growl comes back, but the clutch is still adjusted correctly. Now it seams to be intermittent, mostly it is there, however I can be going up a hill in 2nd at 25mph and the growl will come and go. I have done the following experiments to find where it is coming from.

1, Shift lever pressure- changes tone and volume of growl but does not erase it.

2, Under load\no load- flat or uphill as long as I have any throttle input the growl is there in said RPM range. Coasting down a hill it disappears.

3, Throw out bearing pressure- while experiencing the horrid noise I have applied various pressures on the throw out bearing with no effect on noise.

4, Neutral- while on a slight down grade, disengage the clutch and give throttle input, noise seams to want to rear its ugly head. While sitting in neutral or with clutch disengaged the noise does not appear in any rev range.

5, Alternator Bearings- went for drive with alt belt disconnected, no change.

6, loose fasteners- checked for any loose fasteners at drive train and undercarriage.

7, endplay and run out- both good

8, Clutch- Clutch disc, pressure plate and throw out bearing new at time of rebuild (not that that means anything)

9, State of tune- Plugs, wires, cap, rotor, timing all ok.


I am starting to dislike my bus. I figure I have one of the following;

1, another bad tranny (but it was f**$#* silent on the first test run after install) I think it must be this but why would it be silent and one hour later develop the noise?

2, bad clutch disc, pressure plate or throw out bearing

3, bad crank or cam- no leaks from flywheel or fan seal, rear thrust bearing looks perfect, no noise with my head next to engine through the rev range.

This pain in my stomach is not going to go away until this is solved, one way or the other. Sorry for the long post, but I need to get this off my chest.

[toddb_67]

[jberger]

Yes, same T\O bearing, disc and pressure plate in all 3. They only have about 6000 miles on them. Looked ok last weekend. No broken springs or tangs. The clutch housing is off of the 091 as the clutch\flywheel is different on the 75. I disassembled, cleaned and lubed the T\O bearing fork\operating rod when I freshened the 091, no cracks or bends. As for turning up the radio, I am not one to forget about a potential catastrophe.

[Amskeptic]

Being somewhat of a perfectionist at heart, I feel your pain. I vote for resonance coming through the mounts or sundries attaching the driveline to the chassis. A while back, I had posted about my gearshift rattle search where I finally narrowed it down to slightly unsynchronized carbs. It was causing only a mild roughness in the engine that found a home in the gearshift rod. I also have old rubber in the bell housing mounts. Rubber gets hard over time. The bell housing mounts are the primary weight-bearing mounts for the driveline. The nose cone and engine carrier mounts are to handle drive train torque loads under acceleration and deceleration. The earlier Type 4 buses had a nicely adjustable nose cone mount, and I found that preloading the nose cone helped get rid of some of that growling and it allowed the gearshift rod to press gently against the rear plastic shift rod bushing to get rid of the rattle. Check very carefully both the centering of the engine/transaxle in the chassis, and also, loosen the bracket-to-engine mount crossbar bolts as well as loosening the bracket-to-frame bolts when you check centering. Have your floor jack under the front lip of the case, and jack up until the frame-to-bracket bolts are easy to wiggle. Loosen the 17mm nose cone mount-to-torsion tube bolts AND the 17mm nose cone mount-to-nose cone nuts, they are also 17mm. Wiggle the exchangers from side to side as though you want to make the car fishtail. Now go up and down on the fan housing, you should hear the clatter of the bolts loading and unloading. Tighten the bracket-to-frame bolts, then the bracket-to-crossbar bolts, then push up on the bottom of the transaxle near the nose cone, just enough to see movement at the 17mm nuts, tighten them, then the 17mm bolts that hold the whole thing to the torsion tubes.
If you have an 091 transmission, they are known to be howlers in the lower gears, as were the 002 CA transmissions. Quiet for a week, then when the bearings take a seat, the gears themselves spool ever so slightly out of perfect alignment, and growl city here we come. VW changed the gear teeth count to get rid of that noise in the CA's successors. The 4.86 ring and pinion ratio was perfect as far as harmony with the engine. The later 091 4.57 ratio has a different sound that does not dovetail with the engine resonance, so it is more noticeable on the highway, particularly if you, like I do, have the .82 4th gear. Noise can eventually drive you insane, because your brain is playing the "don't pay attention to the pink elephant" game and you're actually getting more and more focused upon it. I noticed this with my Vanagon. The '89 Vanagon was a quiet car! But the thumping of the Beetle-based lower end was an unpleasant sound, no matter how muffled it was. I would get back in the '73 Bus and enjoy the Type 4 clatter and nicer sounding lower end, go figure. By the way, check your heater control valves to see if they are shoved up against the bell housing truss, that'll give you noise sort of like putting your chin against a pneumatic impact driver.
Colin
_________________
www.itinerant-air-cooled.com

[jberger]

Thanks Colin. I will try aligning the drive train again. The heater control valves are close to the truss but not touching (thought of that too). That pink elephant comment is right on. I tell myself I will just let it go and bound merrily along the highway, but it's the monkey stuffing shit in my ear that I can't ignore. I think my wife is tired of my complaining as well.

[ratwell]

Step by step, how are you bolting in the engine and transmission?
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ

[jberger]

Install tranny, level across flange holes. Install engine, with loose cross bar brackets. Bolt to tranny. Put slight up pressure on engine, then tighten cross bar.

[ratwell]

I've installed both ways (with engine and without) and I prefer with engine although it takes a long time to hook up all the tidbits vs. wrestling with the input shaft.

Last weekend when I did it I had a lot of trouble with one of the transmission carrier bolts: I couldn't get the level right so I could thread in the bolt. Every bus seems to have it's own quirk. I've tried using exaggeration to get it installed in 30 minutes but it only seems to work for posts.

I bolt the engine to the transmission on the floor, take it out to the bus, get the transmission into place (nose cover over torsion bars) then raise the transmission up down until I can secure the the transmission to it's carrier use the two bolts. Then I align the engine carrier clips and bolt them into place. Lastly, I secure the nose of the transmission which I find raises the front of the transmission slightly.

I'm wonder what a spirit level on the hockey stick would read when the alignment is just right.
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ

[Amskeptic]

That bell housing carrier bolt deal is a real treat, particularly when the light is failing and you NEED it to start threading. Because the carrier is on those rubber mounts, it will cock front-to-rear and make it hell on getting those bolts started. By keeping the nose cone mount-to-torsion tube bolts loose, and the engine carrier brackets loose, (you can use the jack for altitude adjustments, once the bolts go through the bell housing your altitude is good enough) you can use a brake adjusting spoon between the carrier and the frame truss to arc it front to rear a little while turning the 15mm bolts, I do the one over the starter first, then you can sort of see the left side one that will be your biggest fight. Not a problem.
Colin
_________________
www.itinerant-air-cooled.com

[ratwell]

Ever noticed that the engine carrier has one set of holes at each end but the brackets have two sets. It is possible to put the clips on incorrectly and put the engine in slightly askew? I would bet not but I haven't tried either.
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ

[jberger]

I don't think it is possible for the carrier brkts to be installed off center. Its a tight fit when aligned properly. Tried a few things last night and double-checked this morning. Nothing seams to make a difference. I suppose I will just drive it until it gets worse. Heading down to Big Basin today, I'll keep my ear open for any change.

[jberger]

Well, I think I found it. Today I went out and removed, disassembled and reinstalled my distributor (looked ok), removed and inspected the fan and fan housing (looked ok), and then for good measure, I stuffed some foam up the rear shift rod housing. Took it for a ride and silence. It seems that the shift rod was vibrating at certain engine rpm's. Blew my mind.

[ratwell]

Good fix. Those problems suck.
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ