1977 Campmobile - Trans noise

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buck
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1977 Campmobile - Trans noise

Post by buck » Mon Feb 04, 2013 3:46 pm

All,

77 Campmobile - has developed a grinding noise in drivetrain. First noticed the sound while driving about 55 in 4th gear. Noise starts when I let off gas (either while shifting gears or easing off from acceleration into cruising speed) and sounds like a scrubbing mettalic grinding noise. Further discovery revealed that noise can be heard in 2nd, 3rd, and 4th gears at high rpms. Noise starts when accelerator is released at gear shifting time. Noise not heard when cruising along at low or medium RPM. Noise goes away when clutch pushed in. Any ideas?

Buck
77 Westfalia Campmobile
Knowledge is not how much you know, but knowing where to find it. - Albert Einstein

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Amskeptic
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Re: 1977 Campmobile - Trans noise

Post by Amskeptic » Mon Feb 04, 2013 6:56 pm

buck wrote:Any ideas?
Buck
Ayep.

A) If Scraping/Grinding sound, check your rear axle nut torques, NOW. Pull cotter pins, and torque to factory spec (253 ft/lbs). Let us know if any was loose.

B) If Whine/Howl/Growl sound:
Achieve 55 mph on a quiet smooth road. Release throttle to get noise in 4th gear. As the car slows down, the noise drops in pitch, yes?
Now, get down to 40 mph and downshift into 3rd, release throttle.
Is noise STILL DROPPING IN PITCH, or has it gone up to the same pitch as 55 in 4th?

If pitch is dropping all the way down through the gear, your pinion bearing/output shaft bearing has likely begun its death spiral.

If pitch came back up at the downshift, then it is more likely one of the input shaft bearings.

Perform a transaxle oil change. Put in nice fresh Sta-Lube 75-90w dino only GL4, available at NAPA.
Check the drain plug for a beard of metal filings. If any are super shiny as opposed to grey, you may have bearing material already shedding. If it is a lot of grey paste, the nose cone thrust plate is getting worn by the shaft drilling into it on decel.

These transaxles are becoming more valuable and more expensive to fix. Get yours done now so you can protect the ring and pinion and other large parts.
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

buck
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Re: 1977 Campmobile - Trans noise

Post by buck » Tue Feb 05, 2013 9:43 am

Colin,

Appreciate the diagnostic tips, changed the trans oil as part of the discovery this past weekend. Drain plug had old metal shavings and grey gunk. Oil was dark brown/cloudy, the last bit to drain was a little frothy.

Will perform the other diagnostic tests and report back.

Thanks

Buck
77 Westfalia Campmobile
Knowledge is not how much you know, but knowing where to find it. - Albert Einstein

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Amskeptic
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Re: 1977 Campmobile - Trans noise

Post by Amskeptic » Tue Feb 05, 2013 11:02 pm

buck wrote:Colin,

Appreciate the diagnostic tips, changed the trans oil as part of the discovery this past weekend. Drain plug had old metal shavings and grey gunk. Oil was dark brown/cloudy, the last bit to drain was a little frothy.

Will perform the other diagnostic tests and report back.

Thanks

Buck
I'll be waiting . . . right here. No, here.
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

buck
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Re: 1977 Campmobile - Trans noise

Post by buck » Thu Feb 07, 2013 5:29 am

Diagnostic tip report

Axle nuts - removed cotter pin, used BA breaker bar (2' long combined w/ 215 lb weight (me)). Axle nut did not budge either way. Assume tight. Repeat on other side - same result.

Driving discovery - 55 mph- 4th gear, let off accel, growl/grind starts high pitch and reduces in pitch as bus slows. 40 mph - 3rd gear (coasting), let off clutch, G/G noise starts high pitch and reduces in pitch as bus slows. 25 mph - 2nd gear (coasting), let off clutch, G/G noise does not start (or is too faint to hear). However, if starting in 1st gear, accel to high shift time RPM, let off gas, G/G noise starts high pitch and reduces in pitch as bus slows. Same thing in 2nd gear. In both cases depressing clutch will make G/G noise go away.

Buck
77 Westfalia Campmobile
Knowledge is not how much you know, but knowing where to find it. - Albert Einstein

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RSorak 71Westy
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Re: 1977 Campmobile - Trans noise

Post by RSorak 71Westy » Thu Feb 07, 2013 5:36 pm

Sounds to me like crunchy bearing in the transaxle.
Take care,
Rick
Stock 1600 w/dual Solex 34's and header. mildly ported heads and EMPI elephant's feet. SVDA W/pertronix. 73 Thing has been sold. BTW I am a pro wrench have been fixing cars for living for over 30 yrs.

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Amskeptic
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Re: 1977 Campmobile - Trans noise

Post by Amskeptic » Thu Feb 07, 2013 11:11 pm

buck wrote:Diagnostic report

55 mph- 4th gear, let off high pitch reduces as bus slows.
40 mph - 3rd gear (coasting), let off clutch, noise high pitch reduces in pitch as bus slows.
25 mph - 2nd gear (coasting), let off clutch, noise no.
However, 1st gear, accel to high, let off gas, noise high pitch reduces as bus slows.
Same in 2nd gear.
Buck
That is so very much like an input shaft bearing. Trans time!
Why did you say growl/grind. Isn't it more of a whine?
If it is not a whine, but a gear clashy sound, try reverse, which is noisy anyway, but see if you can discern that same sound, pop it out of reverse firmly, see if reverse engagement changed the tune of the forward gears. The reason I ask is this: reverse borrows the 1/2 synchro sleeve to drive the reverse idler. Rarely, the output shaft begins to move longitudinally causing the reverse idler to "buzz" lightly against the synchro sleeve.
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

buck
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Re: 1977 Campmobile - Trans noise

Post by buck » Mon Feb 11, 2013 4:05 pm

Colin,

Appreciate the help. Grind/growl noise the bus is experiencing is sim to a bad wheel bearing noise. Not really a whine or gear clashing. Unfortunately, my experience level w/ transaxles and lack of time to attempt removal for complete diagnosis and repair have dictated that the bus be taken to a local german import repair shop.

So I have to work more hours to make more $$ to pay for a bus that I can't use as much because I have to work more. Ain't bus ownership fun!

Down, but not out,

Buck
77 Westfalia Campmobile
Knowledge is not how much you know, but knowing where to find it. - Albert Einstein

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Amskeptic
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Re: 1977 Campmobile - Trans noise

Post by Amskeptic » Mon Feb 11, 2013 7:03 pm

buck wrote:Colin,

Appreciate the help. Grind/growl noise the bus is experiencing is sim to a bad wheel bearing noise. Not really a whine or gear clashing. Unfortunately, my experience level w/ transaxles and lack of time to attempt removal for complete diagnosis and repair have dictated that the bus be taken to a local german import repair shop.

So I have to work more hours to make more $$ to pay for a bus that I can't use as much because I have to work more. Ain't bus ownership fun!

Down, but not out,

Buck
Look at it this way . . . no vehicle you own will appreciate as much as this one. A repaired transmission will increase the value of the vehicle (as long as it is stock) easily the price of the repair (as long as it is a nice vehicle to begin with). If you have a #2 driveable good condition original Westy, its value is right around $8,250.00. If it is a very beautiful specimen, it is just under twice that, $15,250.00. See?
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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