FYI Colin- visit transmission noise findings

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wcfvw69
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FYI Colin- visit transmission noise findings

Post by wcfvw69 » Fri Feb 24, 2017 10:03 am

When Colin visited back in 2015, I had just gotten my 002 transmission rebuilt and reinstalled a couple of thousand miles beforehand. It was rebuilt by a VERY busy and well thought of shop here in Phoenix. After I installed it, I noticed that I had a noise/vibration emanating from the transmission at higher RPM's when under sudden lifting of the gas pedal or deceleration. It was very prominent at say 60 MPH on the freeway when I'd completely lift my foot off the pedal to brake in traffic. The noise sounded like a mixture of vibration/rattle coming from the transmission.. Very odd.

I took the bus to the transmission shop who did the work after calling the owner. He took it for a road test and heard what I was talking about. He put it on the lift and checked around under the bus's engine/transmission area. He wasn't quite sure exactly what the noise was but said he would tear it back down if I wanted. He said he didn't think it was anything that would cause the transmission to fail. He suggested it could be one of two things. I know this sounded vague on his part but he's really honest and straightforward. I decided to hold off yanking it back out and to put a few thousand miles on it to see what transpired.

So when Colin was here, during the road test I pointed it out to him. He heard the noise in 3rd and 4th under hard deceleration without pushing the clutch in. Colin wasn't quite sure what the noise was either.

I've been dealing with the noise with the intention of having the transmission shop tear it back down in a couple of years. Well, my clutch suddenly started to feel lousy and finding gears was getting tougher. It felt like the pressure plate springs were getting weak. I removed the engine and changed the rigid clutch disc that was ok to a spring loaded disc. I then also changed the pressure plate, throwout bearing and pilot bearing.

The bus had a very old looking remanufactured LUK brand 3 arm pressure plate. It was certainly weak and causing my weak clutch problems. After changing all these parts, the road trip demonstrated the pressure plate was indeed weak and the clutch now works beautifully. It also had a wonderful side benefit in that most of that deceleration vibration/noise from the trans is now gone. I'm not sure which replaced part removed this nice vibration/noise from the trans.. Odd
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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Amskeptic
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Re: FYI Colin- visit transmission noise findings

Post by Amskeptic » Mon Mar 06, 2017 12:57 pm

wcfvw69 wrote:
Fri Feb 24, 2017 10:03 am
When Colin visited back in 2015, I had just gotten my 002 transmission rebuilt and reinstalled a couple of thousand miles beforehand. It was rebuilt by a VERY busy and well thought of shop here in Phoenix. After I installed it, I noticed that I had a noise/vibration emanating from the transmission at higher RPM's when under sudden lifting of the gas pedal or deceleration. It was very prominent at say 60 MPH on the freeway when I'd completely lift my foot off the pedal to brake in traffic. The noise sounded like a mixture of vibration/rattle coming from the transmission.. Very odd.

I took the bus to the transmission shop who did the work after calling the owner. He took it for a road test and heard what I was talking about. He put it on the lift and checked around under the bus's engine/transmission area. He wasn't quite sure exactly what the noise was but said he would tear it back down if I wanted. He said he didn't think it was anything that would cause the transmission to fail. He suggested it could be one of two things. I know this sounded vague on his part but he's really honest and straightforward. I decided to hold off yanking it back out and to put a few thousand miles on it to see what transpired.

So when Colin was here, during the road test I pointed it out to him. He heard the noise in 3rd and 4th under hard deceleration without pushing the clutch in. Colin wasn't quite sure what the noise was either.

I've been dealing with the noise with the intention of having the transmission shop tear it back down in a couple of years. Well, my clutch suddenly started to feel lousy and finding gears was getting tougher. It felt like the pressure plate springs were getting weak. I removed the engine and changed the rigid clutch disc that was ok to a spring loaded disc. I then also changed the pressure plate, throwout bearing and pilot bearing.

The bus had a very old looking remanufactured LUK brand 3 arm pressure plate. It was certainly weak and causing my weak clutch problems. After changing all these parts, the road trip demonstrated the pressure plate was indeed weak and the clutch now works beautifully. It also had a wonderful side benefit in that most of that deceleration vibration/noise from the trans is now gone. I'm not sure which replaced part removed this nice vibration/noise from the trans.. Odd
Imbalanced pressure plate?
No damping in the solid clutch disk hub?
Colin?
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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wcfvw69
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Re: FYI Colin- visit transmission noise findings

Post by wcfvw69 » Mon Mar 06, 2017 9:17 pm

IDK Colin,

I called the owner of the transmission shop and discussed it with him. He had a few guesses but no definitive answer. He was happy to hear the noise had gone away. The three arm, reman pressure plate looked OLD. Had I noticed it when I've had the engine out in the past, I would've replaced it. The engine didn't appear to be out of balance at all. It reved smooth thru the entire RPM range with that old PP.

My 67 bug's transmission works perfectly. No noises at all, smooth shifting and no noises. I stuck a dual 44 carbed 2276 engine in it a few years ago to have some fun. The transmission HATED that engine. It made all sorts of whining/vibration noises on deceleration at freeway speeds. I put the stock engine back in and the noise was gone.. Odd..

I'm thrilled that I don't have to R&R the transmission again.

Thought I'd follow up with you and let you know since you were a bit puzzled at the noise too.
1970 Westfalia bus. Stock 1776 dual port type 1 engine. Restored German Solex 34-3. Restored 205Q distributor, restored to factory appearance engine.

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