ZF 320 Input Shaft Bearing

[NLu]

I am doing a refresh on a ZF320 5-spd manual before swapping it into my car with an S52.

Went to change the input shaft seal... drove a screw into the seal and used a slide hammer to pull it out.
But I inserted the screw too far, and punctured the seal on the input shaft bearing behind it.
Here's a picture of the bearing now; puncture can be seen at the 2-o'clock position:



Now when I spin the input shaft, trans fluid weeps out of this puncture in the bearing seal.

I'm trying to figure out if I've FUBAR'ed the bearing to the point that I need to replace it.

My thinking is that this bearing is probably splash-lubricated by the trans fluid.
The seal on the bearing is probably just to keep dust/contamination out of the bearing before it is pressed into the transmission.
The input shaft seal (not the bearing seal) should be providing the function to prevent fluid from leaking out of the trans.

Given this logic, I should be OK in the current condition, and just install the new input shaft seal??

I'm hoping someone who has taken this trans apart and seen the structure of the bearing could chime in whether my logic holds water...

TIA!

[bmwdirtracer]

It seems to me that you'd be foolish to NOT replace the bearing. Pulling a trans is a lot of work, you're already there, and the bearing is going to be pretty cheap.

[NLu]

I've been trying to find info on this trans, but it's scarce. I've read that the input shaft bearing is pressed onto both the shaft and the housing. I glanced at the TIS and looked like I need to separate the trans case to replace this bearing.
Seems like I need some special tools to even separate the case...
That's the reason in asking for opinions.

[bmwdirtracer]

Now THAT'S a really good reason to consider leaving it alone. Sorry that I can't give you a conclusive answer as to the difficulty of replacing that bearing, but you might be able find that info in Michigan:

ZF North America Inc.

15811 Centennial Drive
Northville, MI 48168


Phone: +1 734 416-6200
Fax: +1 734 416-8331
Homepage: www.zf.com/us

[pbonsalb]

I did this about 5 years ago. I tried to research but came up with little. Eventually spoke to a shop in NJ that knew these transmissions. The guy said I poke a hole in a rubber skirt behind the bearing that was not actually necessary for sealing and that the seal that goes in front provides the real seal. Put new outer seal and 5 years later no problems.

[NLu]

The guy said I poke a hole in a rubber skirt behind the bearing that was not actually necessary for sealing and that the seal that goes in front provides the real seal. Put new outer seal and 5 years later no problems.

Thanks for the info! That's exactly what I'm thinking.

Just to ease my mind, I've been trying to find a picture of this bearing online just to see for myself...

- - - Updated - - -

Found a few others that have had similar experience, and echos pbonsalb's comment:
http://www.m3forum.net/m3forum/showt...=268686&page=7

I'm gonna clean up the seal bore surface, put some sealant on the outer flange of the seal, and make sure I don't drive it in too deep.

[pbonsalb]

The bearing has a "skirt" which is the part you punctured. You cannot easily replace the bearing. It will cost you hundreds to have a pro open it up and do it and that is once you find a shop that will work on a ZF. Certain kinds of sealant are recommended over others for the seal. I forget which. Might be anerobic. Drive the seal in enough to fully seat it on the flat area.

[bmwdirtracer]

NLu; pbonsalb know his stuff.

I will caution that the bearing has ball bearings in a cage.. The important aspect of the equation is whether or not you've hurt the bearing's cage - not whether the "skirt", or seal is damaged.

Certainly, if you can't replace the bearing reasonably, you're going to chance it; but don't make the mistake of thinking the issue is confined to the oil sealing.

[RockinScott]

Just did this (F-up) too. Thanks for the post and the replies and the link to the M3forum. Makes me feel (a little bit) better.

I think I will create a new post with an appropriate title to make it easier to find for the next guy.

[bmwdirtracer]

And just to tidy up both threads:

[NLu]

Hmm my original picture got deleted off photobucket, and I can't find it on my computer.

The seal puller that bmwdirtracer suggests is a great tool. I used it to pull the diff output shaft seals, worked great.

However, it can't be used to pull the transmission input seal in question because the input shaft is sticking out from the seal. That's why everyone drills a screw into the seal and use a slide hammer.

Just don't drive the screw in too far...

[namiam]

Bringing this back from the dead. So everyone is saying it is ok if the "skirt" of the bearing has a hole, but is ok if the cage is undamaged? What will happen if tranny fluid leaks into the bearing and the bearing will lose grease? Is that not possible? The thread off another forum practically says the same thing. All threads just say to install the front shaft seal correctly, and just ignore the hole in the bearing skirt. I'm worried about losing grease on the bearing.

I'm a noob... Still learning. So I have a valid point?

[pbonsalb]

My trans was good for about 7 years after I punctured the skirt. I broke it a year or two ago, but think it was from drag racing and hotrodding with 600 rwhp rather than the skirt puncture about 40k miles earlier. Just broke the replacement trans. Too much power again. Probably closer to 700 rwhp now.

[LightsOutt503]

For anyone looking at going to a shop to replace the input shaft bearing I was quoted $3000 for the job. I can buy 3 transmissions for that price. Just buy a new transmission its not worth fixing.