[Vwdiesel] Need Oil Pump Help

[Gavrik Peterson]

Loren,

It looks like you are also a night owl.

>You talking like the relationship between a piston and the bore or how 
>"long" the shaft is?  Since you were able to shim something was it the 
>relationship of the shaft to the vacuum pump or (me tired brain thinks 
>more likely you're saying) with the oil pump installed, the upper shaft 
>support bushing is out of whack.  That might be a bit of a buggar to 
>fix without a mill, or making is sloppy.  It's a pressure oiled bushing 
>I believe so there's where the bigger oil pump comes into play.  ;-)

Actually, I am not sure how my brain is doing right now (need food),
but here goes.

I was trying to say that there is a manufacturing defect in that
particular oil pump.  The defects is that the bushing in the pump
housing -- that the pump shaft goes through, is misaligned.  That is,
the axis of this bushing is not normal to (90 degrees) the machined
mounting surface on the top of the pump, as it should be.  Because of
this misalignment, if one mounts the pump in its proper position, just
using your hand to hold it there, that upper bushing (close to the
vacuum pump) will force the pump shaft into an angle that is normal to
the mounting surface on the block.  This is as things should be.  The
problem is that because the bushing in the pump is misaligned, the
mounting surface of the pump will not be exactly parallel with the
surface on the block.  When you tighten the pump mounting bolts these
two surfaces are forced together and the pump housing rotates through
a small angle.  This causes binding in the pump bushing and the
binding cause the friction that I was concerned about.  There will be
three interferences between the shaft and the bushings.  Two in the
pump bushing and one in that upper bushing in the block.

>Change the pinion depth!   You could check for gear wear but they 
>usually don't show that much.  If boring your bushing properly would 
>put the top of the shaft a bit closer to the int. shaft then that would 
>eliminate some of the play.

I don't understand.  Could you try to explain this again?

>If you replace the 36mm pump (which IS overkill on a non hydraulic 
>and non TD engine) may I have first dibbies on it?

Not sure you would want it given that it has this problem.  I will
have to check to see if the rebuild shop wants it back.


Gavrik