antlee928

HI,
Am underway with a major service on my 928 S4 MY89 that includes TB, WP, OP, tensioner, crank shaft seal plus some other items such as: Beru replacement ignition wire set, replacing both ignition coils.

I am following Dwayne's excellent procedural material for TB replacement - well done Dwayne

So several questions for the the forum:

1. Tensioner bolts - Dwayne seemed to think there is one tensioner bolt that may require some sealant as he believed it may go through to an oil passage. On removal of the this bolt (bolt directly above the oil nipples) it showed signs of having had some sort of sealant material on it. Can the forum advise further and if sealant required is the Loctite 574 ok??

2. Crank shaft seal - is there any special procedure to be observed when removing the old seal and installing the new seal?? Installing with a matching diameter piece of PVC and gently tap it in using a rubber mallet??

Again many thanks to Dwayne for his very informative and thorough guide.

Thanks in advance

Tony

ammonman

Hondabond, Dreibond, Yamabond sealant or Loctite PST non-hardening sealant will work fine for that bolt. Crank seal is simple tap n with a driver as you described. Be sure it goes in the same depth as the old one.

Mike

antlee928

Many thaanks Mike.

BTW, is there a typical life cycle for the front crank shaft seal e.g. 50,000 miles, 100,000 miles, etc???

Cheers

antlee928

Further to my earlier post, my crank shaft seal shows no signs of weeping, leaking, or any other signs of faling. Car has done 250,000kms or 155,000 miles. I realise of course that this is easily changed as a WYIT task. :-)

Cheers

davek9

Given the age of the rubber, what if at 160,000 it starts to leak, what then?

just do it, pops right out with a large screw driver pounded into it from underneath via the notch in the block, then lever it out.

New goes in dry (seal to block) put some engine break in lube on the seal to crank surface.
Make sure you drive it in far enough to cover the Notch in the block, but not too far.
If using the same type of seal, then replace it at the same depth as the one removed.



Dave K

antlee928

Hi Dave, thanks for the advice. When you say engine break-in lube, what do you specifcally mean?.

Cheers

hlee96

Dave, I thought that the crank seal should be flushed with the block and maybe up to 1 mm in. When I took out my old crank seal, I found it to be ~2-3 mm pass the block, and I read it before that that is too deep.

antlee928

Hi hlee96, Just been reading about your Weissach Edition acquisition last year. Nice car

I have read elsewhere that the replacement front crank shaft seal should be at least aligned to where the old seal was situated or, preferably, a little further in (1-2mm) from the old seal's position. I am guessing this has something to do with any seal wear grooves/markings on the crank shaft and to position of the new seal partially away from any such wear. Further guessing this is to mitigate against any possible premature leaking from the new seal.

Cheers

hlee96

Awesome Tony for the info, and thank you. Will push my seal in further then. Slowly putting the euro S engine back together. Hope you didn't mind my hijacking your thread!
-Hoi

antlee928

Hi Hoi,

Please proceed carefully and suggest you seek some further advice from say MrMerlin (Stan) or even Roger at 928sRUS for more definitive advice on the crank shaft seal. Others may chime in here but pleasae note that I am not a mechanic and am a novice in such matters but am very much a DIY kinda guy. As my dear old Pop used to say, "...measure twice, cut once..." :-)

Cheers

davek9

It all really depends on what manufacture the seal is, from what I've see over the years there ate 2 types for the same part.

1. the outer surface is completely covered in rubber (these go in flush) or far enough to cover the removal notch.

2. the outer surface is only covered half way down with metal showing on the edge (these need to be set in deeper) for the rubber to cover the notch.

I found this out by going by what most say on the forum, that the seals need to be flush, not true, it depends on the seal.

Mine was a rear main so it was painful