alexjc4

So the engine's out and I've ordered seals from porsche for the input shaft seal and rms. One of the two was leaking a bit as the bell housing was filthy, hard to tell which though. To be fair most of the grot was from the disintegrated rubber clutch so the level of filth may not be a real indication of the leaks. And I've not seen any drips from that area in three years, which can't be said of the rest of the car.

Anyway I 've been reading horror stories about removing and refitting both these seals, obviously mostly related to the RMS. Especially without any special tools.

So the question for the experts, or anyone who cares to comment, is; is the risk of complications balanced by the minor gains of addressing some fairly minor oil leaks? Or is the "while you're in there" opportunity of having the engine out too good to pass up the chance to do these two?

jevvy964

Both fairly easy tbh.

For the RMS:
I didnt have a pick or seal extractor so I drilled a few tiny holes in the seal(3) and then put some short self tappers into the holes and puled on them using vice grips - seal popped out pretty easily. Look at the new seal to gauge how deep you can safely drill the holes.

Use the old seal flipped over to tap the new seal in - oil on the inner edge of the seal to prevent it grabbing on the crank on first startup but make sure the outer edge is nice and dry if possible. Also if possible try to fit it a mm further into the case so the seal part runs on a nice clean bit of the crank.

For the input shaft seal:
As above for removal and refitting however I think I used a tube of some sort to tap it into place, old seal less usefull on this mission. Also dont tap it too far as it will slide straight into the gearbox and you will have to remove the diff cover to cut it off the input shaft - dont ask me how I know...



Good luck!

alexjc4

Lol its pictures like that that's worrying me!

So based on much searching here's my current plan, does this sound OK?:

RMS

Remove
Don't score crank! Don't mar the case, especially the seal seat channel!

Measure id and od of old seal, along with the depth of crank protruding from seal and buy pvc pipe cap of correct size

Measure new seal thickness

Measure + photo old seal fitting depth from case edge/bevel

Photo old seal in situ

Photo new seal in bag and close up of out and inner surfaces

Couple of options for removing the seal (any advice on must likely for success?):
a)lightly drive screwdriver into the side of the seal using the notch in case provided to deform seal slightly then lever and pull seal out

b)drill and drive a screws into seal face and pull with grips

c)just seal puller

Install
clean crank seal surface and check crank for wear groove, clean seal channel

gently grind away any nics or mars in case that might catch the seal as it goes in - obviously any damage in the crank seal surface are an expensive show stopper. clean carefully after.

pack back of seal with Castrol LM grease (generic lithium/moly wheel bearing grease)

lubricate seal surface groove and crank w heavy engine oil (or Olista Optimoly 3EP?)

lubricate seal seat channel and outer part of seal lightly with blue hylomar or curil-t

use 4inch pvc pipe cap with centre cut out or old seal to drive in new seal, slowly tap tap tap round and round style.

check it's driven in squarely, until seats fully "all the way in"

Measure and check seal fitted depth compared to old seal

Measure old seal thickness and photo outer and inner surfaces for future ref.



Transmission output shaft seal

Remove
insert 2 cv bolts diagonal from each other into output flange to hold against the case ribs

loosen centre nut (not very tight) and remove flange

photo and measure old seal depth from cover

use regular seal puller or screwdriver to remove old seal - easier than the RMS as there is no obstructing shaft in the middle of it!

Install
compare and photo old and new seals inside and out

check if there is a step/stop in the tans cover plate to prevent pressing seal through into the case

pack rear of new seal w LM grease and lube inner sealing lip with same (or 3EP?). Is it worth lubing the outside of the seal w hylomar / heavy oil?

Press in gently, tap tap tap round and round style

Check seal depth or if there is a "step" seat full "all the way in"

Clean and lube sealing surface on output shaft with gear oil and refit, and tighten to correct torque (33lbft?)



Transmission input seal

Remove
Measure depth of old seal

Now the tricky bit. The main shaft/input shaft is totally in the way! There is a factory seal puller - sounds like this is useful but not essential - maybe beg a loaner from a local indy or even OPC? So, do I Mess with hooks and small screwdrivers? Or drill and screw and pull with grips? Or even skip to the end and press it through in to the trans case and remove the LHS cover, remove diff and fetch it from case? Will the diff/pinion need setting up after or can you safely just reinstall?

Anyway assuming I can get it out -

Install
Measure input shaft, seal id and od and buy appropriate pvc pipe to press in new seal

Taking care to press to correct depth, though the guide tube has a step inset so it will press in seal a bit too if needed - or even use longer bolts and use the guide tube to press in the seal in the first place.




This isn't a "how to" - this is a "how do I" - so comments and suggestions welcome

jevvy964

Looks like you have most bases covered.

Only other thing I'd mention is that the splines on the driveshaft flanges are very sharp and its very easy to damage the new seals as you push them through - because I had the diff cover off I ended up using cling film over the end of the splines to protect the seal then removed the cling film before putting the diff back in.

JasonAndreas

Transmission lube has a very distinct smell that is nothing at all like motor oil! And I WOULD NOT remove the input shaft seal WITHOUT the special VW/Porsche tool (#000.721.925.10) that grabs onto the seal and pulls it out. You might be able to find a cheaper alternative at Snap-on's VW dealer site

alexjc4

Thanks for you input Jason, have you done many of these?

True, neither rms or input seal are gushing so there's no nice trail of gold oil to dip your finger in and have a sniff. And tbh the sludge in there doesnt smell of engine oil either, motul is fairly distinctive.

That is the opinion I'd formed, reading others accounts, looking at the thing and remembering the hassle i had with the input shaft on the front diff (that WAS a gusher).

Sadly in the UK those sorts of tools a harder to come by outside of the porsche dealer network. In the US you have a few online sources for these things. I could import the tool from the US but the postage, tax and wait are offputting - having just bought a clutch from vertex. Like I say, maybe I'll see if a local indy will lend or rent one - maybe a RMS arbor too.

alexjc4

Ok the transmission/gearbox input/main shaft seal is definately leaking enough to replace. I cleaned everything up and left it a while (trans still has oil in) and fresh oil is leaking.

I've cleaned around the rms which was much cleaner anyway and theres nothing coming from there, though of course the engine oil is drained so that probably means nothing.

alexjc4

I can recommend the "drill, screw and pull" method for removing the RMS. And the 4inch waste pipe cap for driving the new one in.

Found a large claw hammer was an idea fit to lever out the transmission output shaft seals. The 2 1/2 inch pipe I tried to use to drift the new one in was no good and in the end I destroyed one seal this way, in the end the tap tap tap method hammering directly on the seal got me there.

Not yet attempted the transmission input shaft.

alexjc4

Right, transmission input shaft seal done. Tried drilling/screwing/pulling but couldn't shift it. So I knocked it through into the diff housing, whipped the cover plate off, lifted the diff out and snipped the seal off. Much easier than fiddling around trying to get it from the outside! Re-fitting was just tappy tap around until it was flush then seat it fully by bolting down the release bearing guide tube. Phew! The planning was more stressfull than the doing.

Thanks guys, for the encouragement and thanks Paul Sage for advice on the phone.