1972 915 input shaft oil seal replacement

[KevinG]

I need to replace the input shaft oil seal on my early 915. I know you have to do it from the inside, but do you have to tear the whole tranny apart to get there? The only directional posts I have seen were for a tranny rebuild and not for just a seal replacement.

I have rebuilt my motor, but do not feel comfortable with rebuilding the tranny. Please help.

Thanks,

Kevin G.

[rlane]

Kevin
If by input shaft seal you mean the large seal in the guide tube /bell housing I am in the same boat. I am planning on having either Gary Fairbanks or WEVO do the upgrade where the convert the guide tube to be removable (like all the 915s post mid 73. I too rebuilt my engine but really don't want to tackle removing the gear stacks and LSD to replace this seal

[Eagledriver]

Yes you half to pull the tranny apart and remove the shafts. I was afraid to try this as well until I did it last winter. It was actually much easier than the engine rebuild. The only tricky part is getting the shafts to pull out and undoing the nuts on the shafts. I locked down the tranny with a rope and a long 2x4 to hold it while I loosened the nuts. Playing around with the shafts and wiggling them loose turned out to be pretty easy as well. You can take the shafts to a machine shop with a press to remove gears if you need to do the syncros. If you just are changing the seals you won't need to take the gears off the shafts. Go for it you'll be pleasanty suprised.

-Andy

[zotman72]

Make sure you get that seal in right too. I had to do it twice (arrgh) on my '72 915. I would recommended using some sort of gasket sealer on the seal's outward side. Yes the only way to do it is to take everything out on the '72 915. However there are some beautiful brass bearings in there that the later 915s do not have,-- they used steel instead. YMMV

[kwikt 911]

I did my 72 last summer and was also skeptical. After looking at my tranny on the garage floor and getting prices from local shops of $500 and up, I decided what the hell. It was actually a piece of cake. Like they said the only tough part was getting the input nut loose. I used an air impact(simple). BTW there a few good links on doing this seal replacement specifically. Don't forget to do the "dam" seal trick. Good luck!

Kevin

[ischmitz]

According to the WSM the following transmissions allow change of the input oil seal with special tool P386 from the outside.

915/02 7337375-
915/12 7230507-
915/08 7830838-

Tool P386 is used to pull the old seal out and push the new seal into place.
For what it's worth: When I disassembled my 74 915 for some other required work I found one or two (don't remember) input shaft seals on the input shaft inside the differential housing. I assume the PO or the shop where the car was serviced did not use P386 and and simply pushed the old seal inside for replacement. I don't see why this would be bad. I guess it's a lot easier than tearing the entire transmission apart. Maybe John Walker can comment.

Ingo

[RickGarlock]

Has anyone done the transmission seal in the 72 911? I understand the seal ( which is from the inside) can be done from the outside with a special Porsche tool # P386. I'm looking for someone to tell me they did this with this tool, or has had a shop do this with this tool arrangement. Please help me out here as I do not want to tear into an otherwise perfect transmission. Car has been sitting for years, with VERY low miles on it. Thanks, Rick 410-852-5794