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Discussion Starter · #1 · (Edited)
Hi all,
I have a 1969 VW bug conversion with about 40k miles on it. The transmission was making some noise when I was off throttle..so I figured a rebuilt one would be nice and they aren't too expensive.

1. It blew up after 20 miles. The pinion gear ground up, and it spewed oil all over the flywheel. They rebuilt it, and mailed it back to me.

2. Ever since then, it has been leaking oil from the main shaft into the flywheel area. I took it apart..everything looked okay, and put it together. It slowly leaks...and I drove it, but after 800 miles it got the clutch pad wet enough to slip.

What would cause this?

Some say the alignment might be bad. How can I check what needs to be aligned?

Would excessive motor vibration cause this? The EV motor has always vibrated WAY LESS than the gas motor ever would.

Video of the shaft: https://youtu.be/cxulnAYb7B4

The samba thread asking for help: http://www.thesamba.com/vw/forum/viewtopic.php?t=615137

I also stuck my old transmission in; it makes a terrible noise now (the new one doesn't do this)...so I messed something up in it. Video of me driving the OLD transmission: https://youtu.be/msc0nDlNWlQ

Sama thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=640015

I also have no idea what would cause this..

So, two transmissions but neither work.

Any help or advice would be appreciated!

corbin
 

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No wobble, so input should be ok. You can add shaft spacers to get rid of the play. Leak says somebody forgot a seal or buggered it up during installation. Sounds like a cheapo rebuild.

Grinding noise is probably a bad bearing. Left hand thought based on experience: have you checked the inner wheel bearings? Lots of people like to over tighten that axle nut which destroys the spacer and somewhat after eats the wheel bearing which makes a horrible noise. Couple of other places depending on swing axle or IRS. 69's are either or vehicles depending on chassis number. I couldn't tell from your video.

I'm not a fan of mofoco they were erratic, I used transform in long beach. 2.5 quarts is enough, I have seen them live with a pint in them. How do you know that was your mainshaft in the picture?
 

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Discussion Starter · #3 ·
No wobble, so input should be ok. You can add shaft spacers to get rid of the play. Leak says somebody forgot a seal or buggered it up during installation. Sounds like a cheapo rebuild.

Grinding noise is probably a bad bearing. Left hand thought based on experience: have you checked the inner wheel bearings? Lots of people like to over tighten that axle nut which destroys the spacer and somewhat after eats the wheel bearing which makes a horrible noise. Couple of other places depending on swing axle or IRS. 69's are either or vehicles depending on chassis number. I couldn't tell from your video.

I'm not a fan of mofoco they were erratic, I used transform in long beach. 2.5 quarts is enough, I have seen them live with a pint in them. How do you know that was your mainshaft in the picture?
Yeah, I think the original rebuild was not good, or a mistake was made.

When you say "add a shaft spacer" -- what exactly do you mean?

The grinding noise with my old transmission: It's definitely not an axle nut or wheel bearing; the other transmission in the car doesn't make this sound. I also had a wheel bearing die, and it sounded different.

> How do you know that was your mainshaft in the picture? -- You mean, the picture of the ground gear? MOFOCO's Roy sent it to me and said it to me; he said it was the pinion gear that ground up due to low oil.

My '69 has an IRS.

So far, it looks like my best bet is going to be to figure out how to ensure the transmission perfectly lines up with the motor. I guess I'll compare the main input shaft location to the motor's adapter location. Somehow...

Thanks for the reply!
 

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You have 4 mounting bolts. Take a measurement in a "x" pattern where the center of the shaft goes into the motor using those bolt holes. Both numbers should be the same. Do it exactly that way across the 4 trans holes. They should be the same and to be correct, should match your motor measurement. That is backyard accuracy but for this purpose it is close enough.

The input shaft won't accept that much side play,but unlike American cars has bearings on both ends of shaft and you would have to force it together by torque-ing the bolts. If it slides together with hand force, you are close enough. If input shaft was bad, it would make noises when you spin it by hand. I believe that isn't your problem as you seem to be chewing up the mainshaft.

Irs has bearing adjusters under the side covers. Put trans in neutral and spin the CV joint mounts, listen for noises.

Finally: the factory synchro are known to be weak. They tend to fracture on high performance applications.

There are play measurements on the input shaft that require precision assembly stacks of spacers that the rebuilds should do but usually don't.

Get thee hither to yon library to borrow the Volkswagen idiot book by John Muir. Most nowadays have a copy. Read it.
 

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You have 4 mounting bolts. Take a measurement in a "x" pattern where the center of the shaft goes into the motor using those bolt holes. Both numbers should be the same. Do it exactly that way across the 4 trans holes. They should be the same and to be correct, should match your motor measurement. That is backyard accuracy but for this purpose it is close enough.

The input shaft won't accept that much side play,but unlike American cars has bearings on both ends of shaft and you would have to force it together by torque-ing the bolts. If it slides together with hand force, you are close enough. If input shaft was bad, it would make noises when you spin it by hand. I believe that isn't your problem as you seem to be chewing up the mainshaft.
I see two problems here.

You cannot find the center of the bell housing off the bolts with a simple X. The bottom holes are at 45 degree angle left and right of the vertical centerline, but the uppers are 42 degrees left and right of the vertical centerline. The outer part of the bell housing is a locating ring, the input shaft is right down the center of that circle. Here is one page of Otmar's drawing for a duel motor adapter in a 914, the lower part shows the transaxle bolt holes.

The input shaft has no bearing inside the transaxle unless we are talking about 1960 and earlier Bug (1959 and earlier Bus) transaxles. The input shaft floats on splines inside the final drive section of the transaxle. My EV buggy has a clutchless adapter and the pilot section of the input shaft cut off, so in my case the input is full floating. It has been working since 2000.
 

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I had transmission oil coming out of that area just like you on my VW IRS transaxle. Buy yourself a new "transmission main shaft seal"; they're cheap. Unbolt your motor, pull it off (along with your clutch if you have one) and you'll see the old leaky gasket. Don't bother buying a gasket prying tool from harbor freight, because it doesn't work for this with the deep angle you're prying from. A long flathead screwdriver will suffice to pry out your old one. Lightly tap in your flathead screwdriver into the inside lip of the gasket with a hammer to get it in far enough to pry. Just work the thing out with a bit of twisting/pulling. Then, put a little lube on your new gasket and tap the thing into place. I didn't lose much transmission oil in the process, and it was relatively painless. If you just had the transmission done, this shouldn't be giving you issues... but it's worth trying to fix if it happened to get mounted poorly enough to leak. My motor is well centered with the shaft from what I can tell, and I haven't had problems since I replaced my old gasket. I've only driven about 100 miles though off and on.


You can even look up a youtube video tutorial of this. I set the video speed on 1.5x in youtube to make it more bearable to watch, lol.

Part 1:
Part 2:
 

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Discussion Starter · #7 ·
I had transmission oil coming out of that area just like you on my VW IRS transaxle. Buy yourself a new "transmission main shaft seal"; they're cheap. Unbolt your motor, pull it off (along with your clutch if you have one) and you'll see the old leaky gasket. Don't bother buying a gasket prying tool from harbor freight, because it doesn't work for this with the deep angle you're prying from. A long flathead screwdriver will suffice to pry out your old one. Lightly tap in your flathead screwdriver into the inside lip of the gasket with a hammer to get it in far enough to pry. Just work the thing out with a bit of twisting/pulling. Then, put a little lube on your new gasket and tap the thing into place. I didn't lose much transmission oil in the process, and it was relatively painless. If you just had the transmission done, this shouldn't be giving you issues... but it's worth trying to fix if it happened to get mounted poorly enough to leak. My motor is well centered with the shaft from what I can tell, and I haven't had problems since I replaced my old gasket. I've only driven about 100 miles though off and on.


You can even look up a youtube video tutorial of this. I set the video speed on 1.5x in youtube to make it more bearable to watch, lol.

Part 1:
Part 2:
Yeah -- the main seal was new...so I'm surprised I'd have to replace it. But, I think I'm going to try to come up with some way to do some accurate measurement. It might involve making a template out of aluminum to compare things. I'll also replace the seal.

Thanks for the help!

corbin
 
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