Should the Central Clutch Shaft be replaced when doing the clutch? Mine looks ok but seems to have play when inserting the spline end into the clutch disk. This is just assembling it on the workbench, is this a part that should be changed out? I was wondering if there is a min diameter spec on the shaft that goes into the pilot bearing? Anything else to look at on this part while it’s out?

 

If the shaft is damaged you will probably see heat marks. If you check the cost of a new shaft you'll probably decide to try the old one anyway...

 

Some play in the splines is normal. Wear in the areas where the clutch disc hubs ride is not good. This will usually present itself as a notch worn on the splines. Look very closely in these areas of the splines - rub your fingernail over the areas and feel for a notch or step. This type of wear will prevent the clutch discs from releasing.

 

Matt,

Thanks for asking this. I'm at the same point as you right now on mine.

I noticed on mine that you could tell where the two positions of the clutch were riding (all the way in and all the way disengaged, I guess). It isn't 'dished' and there isn't any noticable material missing, but you can tell where it was riding and I probably could find it with my fingernail and my eyes closed.

Scott (or anyone),
Is this something that maybe you could tell from a hi res pic for Matt? I was planning on re-using mine, but if this will cause premature wear I'd suggest replacement (for me and you).

Matt, just suggesting maybe the experienced wrenches here would be better able to decide if you could show the condition of the splines.

 

My last clutch job I replaced everything between the torque tube & the flywheel.

 

IF the grooves are minor, try using some valve lapping compound btw the shaft and disc to smooth them out. Make sure that you use the recommended lubricant on install.
On the clutch jobs I've done I end up replacing about 1/2 of the shafts due to excessive wear.

 

So, what does a new shaft cost?

I ask because late last year a "kink" developed in the clutch throw; my wrench took a superficial look at it to make sure there wasn't a cylinder issue and speculated that it was just some wear on the sleeve. But when I took it to him for some other servicing last month I asked him to open it up and rotate the sleeve to make the kink go away. Glad I did, because he found some very poor clutch work from a previous job and he says next time we do a clutch job the shaft is going to have to be replaced. He said that there was a plate installed backwards, the shaft wasn't greased, and some bolts were loose. Sounds like I was very close to a disaster. In any case, the sloppy work means a damaged shaft.

 

$125-$180 on the 928 intl website, (used vs. new)

 

http://www.mailordercentral.com/928i...421%20235%2016

 

This is a wear item , 15 years ago when we took apart a car the shafts usually looked pretty good. But now most of the shafts we see are worn. A new shaft is about $180.

 

Talk about getting shafted.

 

It looked good to Matt and I - there is no notching or heat damage at all. The splines look fine. Matt's asking because of the small play and my lack of knowledge about any specs on the ball end that fits the pilot bearing.

 

For something you replace once every 20 years?

Look up the intermediate disc on a duel disc setup if you want to talk about expensive wear items.

 

It was a pun... pretty punny too if you ask me!

... getting shafted when buying a shaft... get it? Shaft... shafted.... oh man those PA guys know how to tell jokes!

 

When Porsche stops making the clutch shaft .....THEN we are shafted ....and $180 will seem like a bargain !