'81 Vanagon transaxle noise(s)

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SlowLane
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'81 Vanagon transaxle noise(s)

Post by SlowLane » Mon Jun 15, 2015 1:11 pm

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Clonk, clunk, rattle, rattle, Kzzzzzzt.

These are a few of the noises emanating from my drivetrain which have been starting to prey on my otherwise blissful rambles in the van.

The clunking/rattling sounds rather like a large marble rattling around in a wooden box (and yes, I did check my camper drawers and cabinets for errant lost marbles). It seems to come from the rear right side and is nominally related to suspension action. My initial thought was a loose shock mount (because I once owned a '69 which had a broken upper shock mount that sounded kinda like this), but inspection of the shocks and mounts shows no apparent problems there.

My suspicions then turned to the CV joints, which preyed on my mind until I had utterly convinced myself that they were indeed the culprit. So I ordered a set of 4 Loebro/GTK CV joints from Van-Cafe and installed them yesterday, exulting in the warm glow of doing right by my ride and getting good and greasy in the process. Well, of course, that didn't fix the noise. Still got that rattly marble-inna-box sound. I replaced the rear wheel bearings a few years ago just before moving to California, so they have fewer that 5000 miles on them and shouldn't be the problem (though if memory serves, I sourced the bearings from CIP, before I learned the bitter lesson to never buy anything from that outfit again) . I'm probably going to get a friend to drive the van around while I rattle around in back myself to try and pinpoint the noise. I'll wear knee-pads and a bike helmet as a nod to passenger safety. :cherry:

Another noise has started to worry me more though: I first noticed a brief moderate-to-high pitched "kzzzzzzt" when I shift from 2nd to 3rd or from 3rd to 4th a couple of weeks ago. It's been getting more prominent in the interim, and quite pronounced and more prolonged when I shift down from 4th to 3rd and use the engine to decelerate. I'm thinking that the final drive may be on its final legs, but I haven't dug into any further diagnostics yet. The transmission shifts smoothly with no balking. Could I simply be low on transmission oil? in my haste to finish the CV joints, I plumb forgot to check the fluid level while I was under there with the van up on jack-stands.

As far as I know, this transaxle is the original one on the van, which has just turned over 154,000 miles. I note that there are at least three reputable re-builders of the 091 transaxles out there (Rancho, AA Transaxles and German Transaxle), but who knows for how much longer? Is it time to give one of them some of my business while they are still in theirs (this in reaction to the news by the proprietors of Long Enterprises that they will be retiring by the end of 2015).
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: '81 Vanagon transaxle noise(s)

Post by Amskeptic » Fri Jun 19, 2015 6:55 am

SlowLane wrote: The clunking/rattling sounds rather like a large marble rattling around in a wooden box
inspection of the shocks and mounts shows no apparent problems there.

moderate-to-high pitched "kzzzzzzt" when I shift from 2nd to 3rd or from 3rd to 4th
Check actual torque of shock bolts/nuts and exercise the suspension with some leg lifts to see if the rubber to metal has failed.

Needle bearing failure in the mainshaft to some gear? Every time the shaft spins up at the behest of some synchronizer, you will get a sort of whining. This being a constant mesh transmission, all of the gears are always spinning. Also, there are some synchronizer rings that can be noisy. They make noise only when they specifically are being asked to perform their task.
Colin
2019 Annual Funding Drive!
**********************************
https://itinerant-air-cooled.com/viewto ... 41&t=13755

BobD - 1978 Bus . . . . . . . . . . .111,145 miles
Chloe - 1970 bus . . . . . . . . . . . 206,812 miles
Naranja - 1977 Westfalia . . . . . 97,060 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 76,650 miles

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SlowLane
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Re: '81 Vanagon transaxle noise(s)

Post by SlowLane » Fri Jun 19, 2015 1:02 pm

Amskeptic wrote: Check actual torque of shock bolts/nuts and exercise the suspension with some leg lifts to see if the rubber to metal has failed.
Leg-lifts, eh? It's been a looong time since I saw a gym. This should be interesting. I'll probably just un-mount the shocks and inspect the bushings under good light. The shocks I'm using are Bilstein Touring. Fairly new, but they have this cheapish plastic dust sleeve that looks like it would rattle around a lot. Might be time to upgrade back to stock Sachs/Boges (oooorrrrr Konis :bounce: )

The alternative I'm considering is to get myself a Steelman ChassisEAR diagnostic tool or its little sibling the Mini EngineEAR. Pretty interesting idea for diagnosing/pin-pointing noises way back there. I am presently suspecting the wheel bearings. As I said, I think I sourced them from CIP, and that company seems to have a knack for finding and selling sub-par products in every category, even ones you wouldn't think of such as bearings.
Amskeptic wrote:Needle bearing failure in the mainshaft to some gear? Every time the shaft spins up at the behest of some synchronizer, you will get a sort of whining. This being a constant mesh transmission, all of the gears are always spinning. Also, there are some synchronizer rings that can be noisy. They make noise only when they specifically are being asked to perform their task.
Colin
Thanks for those suggestions. I feel a perfect fool now. Turns out the kzzzzt noise was coming from my alternator, which buzzes like an angry hive from 2700-3000 engine RPM. Of course, pretty much every gear shift traverses that speed range, so I was second-guessing that it might be a worn-down clutch disc if not the tranny itself.

I very nearly pulled the trigger on ordering a rebuilt transaxle from German Transaxle of Bend OR. Very nice folks they are, and quite willing to step up and ship me an expedited unit so that I could go ahead with my travel plans next month. When it does come time for a rebuild, I will definitely go to them first.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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SlowLane
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Re: '81 Vanagon transaxle noise(s)

Post by SlowLane » Wed Jun 24, 2015 9:46 am

I really need to start trusting my first instincts instead of second- and third-guessing myself.

Took a chance that it was the shocks and ordered a set of Konis from Tire Rack (the 25% off sale cinched the decision).

The Konis arrived yesterday. Installed the rears this morning. No more clunk-clonk! :cheers:
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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SlowLane
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Re: '81 Vanagon transaxle noise(s)

Post by SlowLane » Mon Jul 06, 2015 5:21 pm

SlowLane wrote: I feel a perfect fool now. Turns out the kzzzzt noise was coming from my alternator, which buzzes like an angry hive from 2700-3000 engine RPM. Of course, pretty much every gear shift traverses that speed range, so I was second-guessing that it might be a worn-down clutch disc if not the tranny itself.
Well, once again I fooled myself. Replaced the alternator with a reman Bosch unit and the "kzzzt" was still there. Well, the old alternator had some serious wear on the commutators, so it wasn't a total waste of effort.

The "kzzzt" turned out to be the loose muffler strap that my muffler guy had tack-welded to the muffler itself, but he hadn't bothered to hook the top end of the strap into the hook provided for that purpose on the crossover pipe. The strap was rattling against the tin underneath the alternator. :blackeye: Geez.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: '81 Vanagon transaxle noise(s)

Post by Amskeptic » Thu Jul 09, 2015 9:03 pm

SlowLane wrote: The "kzzzt" turned out to be the loose muffler strap that my muffler guy had tack-welded to the muffler itself, but he hadn't bothered to hook the top end of the strap into the hook provided for that purpose on the crossover pipe. The strap was rattling against the tin underneath the alternator. :blackeye: Geez.
Geeze Louise . . . . I am using a nice long CV bolt on a slightly short strap to allow snugging up every 10,000 miles.
Colin'

Image
2019 Annual Funding Drive!
**********************************
https://itinerant-air-cooled.com/viewto ... 41&t=13755

BobD - 1978 Bus . . . . . . . . . . .111,145 miles
Chloe - 1970 bus . . . . . . . . . . . 206,812 miles
Naranja - 1977 Westfalia . . . . . 97,060 miles
Pluck - 1973 Squareback . . . . . 55,510 miles
Alexus - 1991 Lexus LS400 . . . 76,650 miles

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