Oil Seal Leak 5TQ

[Dr. Ian McArthur]

I am having difficulty with a leaking front crankshaft oil seal on my 1988
5TQ.  The first new seal I installed still leaked.
The crank has a noticeable groove where the seal lip runs so I installed a
second new seal flush with the front of the case (rather than inset) as
described in the Bentley manual.  The seal still leaks.  I suspect that the
lip is not in quite far enough and is overlapping the notch in the crank for
the vibration damper keyway.  Or maybe I damaged the lip.  I have the proper
Audi tool.
Also, I have two different seals available, both 35x48x10.  One is labeled
"ELRING 2", the other is KACO DGS 35.48.10RF01 with a VW / Audi emblem
stamped in.  Part number appears to be 069 115 147E.  The position of the
seal lip relative to the rear of the seal casing appears to be different:
one appears to be about 5mm from the back, the other 6mm.
I think the trick is probably to very carefully set the depth of the seal
lip to fall in the small range from the inner end of the keyway slot to the
groove in the crank from the old seal.
Questions:  Does anyone make a thin metal tube or collar to fit over the
crank and provide a new surface for the seal to run on?  I have used these
in the differential of my old 83 Mustang and understand from my American car
parts supplier that these are quite common.
I have heard somewhere on the list that the Audi engines have an oil leak
problem from the front of the engine that is caused by oil leaking through
the threads on the bolts that attach the oil pump housing.  I seem to recall
that some of these bolt holes are bored right through the casing or
something and may need to be sealed.
Any other thoughts would be appreciated.
Thanks
Ian