Axial Play
 

I started to disassemble my motor because there was some axial movement on the crank. As I got further into it, I found a few other problems, but now I have split the case. This is what I found:

#1 Bearing has brownish/copperish marks on it. The engine is a 911/81. The bearing has the part # 901.131.00 on it. Was this the right bearing? The reason I ask is that the small tab that seats the bearing into the channel seems to be too small, allowing all this play. The other reason is that if I look in the Porsche Part and Tech. Ref. Catalog, the proper part # begins with 911 or 930. Of course, the tab could have worn if the bearing spun...

There are wear marks on the case at each bearing. According to the book, this isn't a biggie. Caused by the bad #1 bearing.

Anyways, I though I would share this with the group. On to the next step.

I've attached some pics of the damage.


http://forums.pelicanparts.com/uploa...1111818506.jpg http://forums.pelicanparts.com/uploa...1111818611.jpg

Not good news I'm afraid.

You must determine what is causing the axial play (endfloat) before going any further.

It is possible the crank has been wrongly machined..it needs to be very carefully measured especially the dim between the thrust faces on No1.

The most likely possibilty tho from what youve said ( the pictures are not working well enough for me to see) is that No1 main has been moving in the case.
A line bore will solve this if not too bad..

Expensive either way, tho you may have already budgeted for the line bore I guess...

Kind regards
david