928porschepatrick

So i took my tranny because it was leaking. but once out i decide to more more than that....

So my question is i have a lot..... is this normal B1 wear ?

Bill Ball

I've only seen a couple of these. I saw that imprint on the piston on both a low and high mile tranny. I would call it acceptable although I see what look like some burn marks. The band itself looks much more chewed up and more dirty or burned than I have seen. Since you have it out, replace it. Measure the end gap in the clutch pack (should be about 1mm or so - see WSM) and disassemble the clutch pack to check the condition of the metal and friction discs. Based on the band wear, I would expect to replace the friction discs. You SHOULD go the rest of the way and remove and tear down the B3 clutch pack, although that requires pinion gear removal. At least check the height of the B3 pack as shown in the WSM. How was the tranny shifting before you took it apart?

Bill Ball

Here's some piston pics. Left is 240K miles; right is under 100K miles.

928porschepatrick

Thanks Bill,
Shifting at low speed was good.... but with WOT and kickdown pressed its seems the tranny hold up for a second, i don't know exactly how to explain (like a light switch on off ) or it wouldn't go into 4th gear

I will take some pics off the friction discs.

928porschepatrick

I've Measured the end play between outer clutch plate and snap ring with a feeler gauge. Clearance was 3.3 mm. that's not a good start

Bill Ball

You have some work to do. As I mentioned, check the B3 height as well. The WSM shows how to measure it in volume 3, section 17, pages 156-7. If the gap is too large, you need to get into the B3 clutch pack. Fun and games. Mine was SLIGHTLY out of spec. I left it alone. Do you have experience doing auto tranny rebuilds? After my novice experience with this, I have to admire people who jump into this. Lots of unknowns and uncertainties even with all the books. Someone with more experience will have to say whether you need to go all the way to the K2 pack. If B3 is out of spec, then you are headed that way. There are several people here with lots more experience who should pipe in once they see this.