Eric Buckley

Hi Folks,

I have a rebuilt Power Steering Pump and a used Pulley to go with it, but I don't know if there is a correct orientation for the pulley to go onto the pump. The pump has a roll pin to locate the pulley to the pump, but there are 6 holes in the pulley that fit the roll pin, so the pulley could be installed 6 ways. The pulley is not symmetrical, in that it has 2 places where small pieces of metal are welded to the outside of the pulley, maybe for balance? The 2 small pieces are about 150 degrees apart around the pulley. So, my question is: I there a "correct" way to install the pulley as regards the relative position of the roll pin and the 2 small pieces welded to the pulley? In the pictures below you can see the roll pin and the small pieces of metal welded to the outside of the pulley.


Roll Pin

Rectangular Small Piece

Circular Small Piece

Mrmerlin

put the pulley onto the hub and bolt it on any way you like,
the roll pin is extra insurance that the hub wont shear off the bolts.

Eric Buckley

OK Stan. Will do! Thanks.

Mrmerlin

those bolts you have pictured should not have the heads hitting the center pump shaft ,
or get non flanged bolts with flat washers

Eric Buckley

Thanks for your vigilance Stan. Those flanged bolts are the PET specified ones, P/N 999 072 005 09. There is just the tiniest bit of clearance between the flange and the shaft. There is a bit more clearance than the picture below manages to show:

Flange is very close to shaft

Rob Edwards

Huh, that's very strange- 999 072 005 09 is an M6x12 hex bolt and is used in a million places on a 928. It has been superceded to 999 072 005 01, which is indeed a flanged head bolt.

http://www.autoatlanta.com/results.p...r2=99907200501


The power steering pump pulley bolts are prone to failure, good discussion of the solution(s) here:

https://rennlist.com/forums/928-foru...y-failure.html

Eric Buckley

Thanks Rob.

Well, I had ordered 999 072 005 09. The package had a hand-written '005.09' on it (see picture), but it seems that 005 01 was actually provided.

Thank you very much for the link, interesting if sobering reading. I have a box of nice M6x12 bolts with chromate finish I could use here, but they are 8.8. I see that Greg Brown is recommending a change to 10.9 hardware and increased torque. I think I'll try that, but my local good hardware store probably only has 10.9 in M6x15 (vs. 12). I am thinking of adding a washer to spread the load across the face of the pulley a bit more, which would help use up some of the extra 3mm.

005.09

Mrmerlin

yes use a washer no matter what bolt you use,
and make sure its not too long as it will go through the mounting hub and bottom on the pump body