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corbin_dunn Wed Dec 24, 2014 10:09 am

Hi!

My 1969 VW bug's transmission is leaking oil out of the flywheel housing, and I'm not sure why. The transmission is freshly rebuilt by Mofoco. Any ideas what is wrong?

I have an email out to Roy at Mofoco about the issue too.

Longer story:

Last tranny was noisy so I ordered a rebuilt one from Mofoco. Took over a month to get it; I installed it, filled it up with close to 2.5 quarts of oil and drove it about 20 miles. While in 3rd coasting, it started making a really bad grinding noise, so I pulled over and it was pouring oil out of the flywheel housing area. I got towed home, took it out, and the flywheel was covered in oil. I mailed it back to Mofoco. Roy sent me a picture that the ring and pinion was burned up (picture below) and said I probably didn't put enough oil in it. He repaired it for free (I paid an extra $155 for shipping).

I put it in last week and was VERY sure to put 2.5 quarts of oil in while level. I drove it ~45 miles, and now it is leaking oil out of the flywheel housing again!

What would cause this??
Should I keep driving it, or will it burn out the ring and pinion again?

thanks,
corbin


Mr.Duncan Wed Dec 24, 2014 11:16 am

Sorry, that really sucks. Not sure whats wrong.

Also, $150 for shipping seems a bit.. High?

Stop driving and ask Roy.



We get our rebuilt transaxles from The Wright Gearbox. Never had issues with them...

http://www.wrightgearbox.com/

EVfun Wed Dec 24, 2014 11:49 am

This is likely a dumb question but... did the input shaft seal get installed before the engine was installed? I imagine they would puke all their oil really quick without that seal.

Dougy Dee Wed Dec 24, 2014 1:34 pm

When did pinion bearings change from the 4 bolt style to the big nut?

modok Wed Dec 24, 2014 2:12 pm

The input shaft seal can be damaged if your pilot bearing in the gland nut is/destroyed missing.
Some brands of seal and some trans you have to be careful not to push the input shaft sideways too much, as the seal can be bent.... but the OE type ones this isn't a problem, and most IRS trans not a problem either.

Maybe the input shaft is bent? Maybe the engine does not center properly on the transmission?

Those are some things to check at least, but likely.......none of the above.

Some trans are bad apples and I think you got one.

2.5 quarts is the right amount, but 1.5 quarts would be enough to work OK IMO.

modok Wed Dec 24, 2014 4:44 pm

You should have mentioned this is an electric car!!

EVfun Wed Dec 24, 2014 5:26 pm

??? Mine is electric, but why do you think the OP is talking about an EV VW?

windfish Wed Dec 24, 2014 6:18 pm

EVfun wrote: ??? Mine is electric, but why do you think the OP is talking about an EV VW?

He likely went and checked corbin's past posts, ie - http://www.thesamba.com/vw/forum/viewtopic.php?t=610195&start=10

And it does make a diff if the problem is the front seal, my first thought would be the adapter plate on the electric motor isn't quite right and it's destroying the seal, or you didn't put in a pilot bearing.

modok Wed Dec 24, 2014 9:42 pm

Exactly.

How much you wanna bet the old one leaked too :wink:

corbin_dunn Wed Dec 24, 2014 10:38 pm

Yes, it's electric (http://www.corbinstreehouse.com - Plug Bug), but I didn't think that made a difference. At least I know leaking oil isn't coming from the motor!

I don't believe my old transmission leaked at all; maybe a tiny bit.

Yes -- shipping was high, but I paid for there and back.

Roy did write me back and offered to take a look at it; it's just a pain to have to take it out, mail it to Wisconsin (I'm in California) and wait. I was hoping I could solve the problem myself.

One thing that is new is I did put in a new pilot bearing when I installed the transmission; now you have me wondering if it isn't seating into my adapter coupling correctly. But I don't seem to get any excessive vibration (no more than normal with this setup).

I'll take it out (probably in a few weeks), and see if everything is lined up right and replace the input shaft seal.

If anyone else has any ideas I'm super interested for possible problems. Thanks!!!

corbin

corbin_dunn Wed Dec 24, 2014 10:42 pm

windfish wrote: EVfun wrote: ??? Mine is electric, but why do you think the OP is talking about an EV VW?

He likely went and checked corbin's past posts, ie - http://www.thesamba.com/vw/forum/viewtopic.php?t=610195&start=10

And it does make a diff if the problem is the front seal, my first thought would be the adapter plate on the electric motor isn't quite right and it's destroying the seal, or you didn't put in a pilot bearing.

The interesting thing is I have ~37,000 miles on this setup with my old transmission. I did take my motor coupling off; now you have me wondering if I put it on slightly too far forward, causing it to not support the input shaft on the pilot bearing.

corbin

modok Wed Dec 24, 2014 10:47 pm

Yep hate to be too rude, but it's possible.

There are two different length input shafts for late bus trans so us "internal combustin" guys can end up with the same problem.

Engine/motor alignment to trans is hard to check, I wish I had a hint for you th4ere but I don't.

gears Sat Dec 27, 2014 7:57 am

You are showing us a photo of a severely overheated & seized 1st gear needle bearing assembly. The R&P mesh isn't where the damage is occurring. Does this gearbox remain in 1st gear at all speeds? .. or does it remain in 1st more than normal?

Anyhow .. you're asking for answers, so please show us photos of all 1st gear components. The R&P isn't the problem area.

corbin_dunn Tue Oct 13, 2015 12:12 pm

Hi everyone,
I'm still having this same problem. Here's a video of the shaft:

https://youtu.be/cxulnAYb7B4

It seems to have a lot of rock to it.

I drove it only about 1000 miles, and the thing slowly leaks oil, which gets on the clutch pad and starts slipping.

If this is an alignment problem -- then how do I find out what is not aligned?

Where should the shaft sit on the pilot bearing? I can do some careful measurements to make sure that is right. It is also surprising as I had so few problems with my last transmissions with regards to alignment.
@gears -- I actually never use 1st gear; I started in second and go through them up from there. It goes through all the gears with no problem. Is there something going on inside that could cause excessive vibration and leakage?

thanks everyone! I'm sort of at a loss on what to do, and I really miss driving the car. I put the old transmission back in...but that one makes some bad noise (i'll start a thread on that).

-corbin

EVfun Tue Oct 13, 2015 2:39 pm

That movement in the input shaft is normal. It is not supported in a bearing at the other end, instead being held in splines. Make sure the input shaft cannot pull out by hand, that would indicate a certain fastener has come out. The input shaft bearing should be fine running on any part of the strait smooth area at the end.

My EV setup is clutchless and the pilot are of the input shaft has been cut off. I'm running it in the splines turned from an input to mainshaft coupler out of a Bus (the Bug one has the same splines but none of them where quite large enough in diameter to make my coupler with.) My setup has been working for 15 years.

I'm inclined to think that the leakage is poor alignment of the motor.. I'm not sure why slight motor shaft misalignment would damage either the main shaft or pinion shaft bearings. Perhaps it is too tight and butting up hard when you bolt the motor in place, pressing on the main shaft bearings.

corbin_dunn Wed Oct 14, 2015 8:18 am

EVfun wrote: That movement in the input shaft is normal...
I'm inclined to think that the leakage is poor alignment of the motor.. I'm not sure why slight motor shaft misalignment would damage either the main shaft or pinion shaft bearings. Perhaps it is too tight and butting up hard when you bolt the motor in place, pressing on the main shaft bearings.

Thanks Paul!

The tricky part is me figuring out how it is misaligned. Hmm...this is going to be tough to figure out. I also wish I could get my old tranny working, as I would just run it a bit and see if it has the same problem (or not). It makes terrible noise though.

If anyone else has tips, let me know!

corbin

Bob Brugge Wed Oct 14, 2015 9:10 am

I am wondering what went bad in the first trans. Also wondering how the old trans and the new trans are different. If at all.
Is it eating seals?

corbin_dunn Thu Oct 15, 2015 7:45 pm

Bob Brugge wrote: I am wondering what went bad in the first trans. Also wondering how the old trans and the new trans are different. If at all.
Is it eating seals?

Hi Bob,
I don't know why the old one went bad. The symptom was that it sounded louder than I though it should when I was coasting. I figured a rebuilt transmission at $700 or $800 would be a pretty easy solution. In the end, it has been a nightmare. After I ordered a new one I took a peek inside the old one's side cover, but I didn't see anything wrong. But, for some reason, this affected it, and now it makes a *lot* of noise (see my other thread and video).

What is the diff between the old/new? That's a good question! I don't know.

corbin

Volks Wagen Fri Oct 16, 2015 2:13 am

I would start checking the motor to see if that has moved out of it's jig or alignment. It's basically shafted 2 trannys... so the common thing is the motor and it's placement/support etc. AND the tranny mounting. Perhaps it's vibrating, twisting, bearings(?) or something loose... I can imagine the torque... are the tranny frame arms twisted? Maybe if you horse up a few more pics showing the setup of the motor it's mountings to the trans etc?

ROCKOROD71 Fri Oct 16, 2015 5:13 am

corbin_dunn wrote: Bob Brugge wrote: I am wondering what went bad in the first trans. Also wondering how the old trans and the new trans are different. If at all.
Is it eating seals?

Hi Bob,
I don't know why the old one went bad. The symptom was that it sounded louder than I though it should when I was coasting. I figured a rebuilt transmission at $700 or $800 would be a pretty easy solution. In the end, it has been a nightmare. After I ordered a new one I took a peek inside the old one's side cover, but I didn't see anything wrong. But, for some reason, this affected it, and now it makes a *lot* of noise (see my other thread and video).

What is the diff between the old/new? That's a good question! I don't know.

corbin

Your first mistake was going with a company halfway across the continent when there are easily half a dozen reputable tranny rebuilders in California. Now you've likely doubled your cost with shipping when you could have driven the busted unit to the shop where it came from. Despite cost, when dealing with engines and transmissions, going local is always a better option. Ask me how I know!



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