Replacing transmission gaskets

[rolls 912]

Hi

I'm looking to install the big new gaskets between:

• Nose to gear housing
• gear housing to transmission

Is it just a case of removing the perimiter case nuts - slide off the relevant case section , add the gasket etc, or do I need to actually remove the "inards" to remove the case?

I hope this makes sense....

TIA

Roland

[Peter Zimmermann]

What year trans? A 912/early 911 has a nose cover and a main housing. A 915, from '72, has a nose cover, a center housing, and a differential housing. Some gear/shaft dis-assembly is required to do a 915. Why do you want to replace gaskets?

[rolls 912]

Hi Peter

Yes its from a 3.2 1985.

I have the transmission out and armed with a gasket set (dangerous I know)

The center section that connects to the diff housing looks as if it has no gasket - just a liquid gasket arrangement.

Keen to simply tidy up the trani.

Any thoughts?

R

[sc_rufctr]

I can understand the desire to clean up the trans but if it's not leaking...

LEAVE IT ALONE!

[rolls 912]

I'm definitely a candiate for "if ain't broke - don't touch it"

... However, there is an issue with the lack of a gasket and I would hate to reinstall everything and then find a leak. Just keen to know - do i need to remove the inards to get to this gasket or can I just unbolt the "shell"

Thanks for the replies

[sc_rufctr]

That's the problem...

To add/replace the gasket at the differential end you have to take the mid section off.

To do that you have to undo two large nuts at the end of the input shaft and the pinion shaft.
(Not to meantion removing 5th gear, 5th gear slider, reverse gear...etc)
You can only reuse one of these nuts (input shaft). So you have to buy a new nut for the pinion shaft and then torque both back to spec.
The torqueing of these two nuts should only be done on clean/dry gears and shafts....

To replace the gasket towards the nose you can remove the nose section without disturbing the gears but be careful not to loose the small pin
that operates the reverse light switch.

[yelcab1]

leave it alone, is good advise. On your 85, the nose comes off pretty easily, but the mid-housing requires major surgery. Leave it alone is very good advise.

[ChrisBennet]

If it's leaking, I'd fix it if you can find someone to help you who's knowledgeable. If you were local I would. If you put your location in your profile, you might find you have a Porsche friend right next door.

I reuse both nuts, even the collared one. I'm just careful not to tear the collared part. When I put the collared nut back on, I return the "dimple" to it's original location, no torque measurement required. My reasoning is that torquing that nut is crude way of measuring the desired stretch or preload on the shaft. If you can put the nut right back where it was, you've reproduced the desired preload exactly.

-Chris

[yelcab1]

Originally Posted by ChrisBennet

If it's leaking, I'd fix it if you can find someone to help you who's knowledgeable. If you were local I would. If you put your location in your profile, you might find you have a Porsche friend right next door.

I reuse both nuts, even the collared one. I'm just careful not to tear the collared part. When I put the collared nut back on, I return the "dimple" to it's original location, no torque measurement required. My reasoning is that torquing that nut is crude way of measuring the desired stretch or preload on the shaft. If you can put the nut right back where it was, you've reproduced the desired preload exactly.

-Chris

I am Ok with that method but I know that other professional have chewed me out for it. So the last time I did it, I torqued it rigjt.

[rolls 912]

Thanks everyone for your repsonses. I'll guess I'll leave it and see what happens....

Cheers

Roland