re: v6 timing belt question

[steve@ipecac.engr.sgi.com (Steve Valin)]

randrews@post.cis.smu.edu (Robert Paul Andrews) writes:

> I was going to be changing the timing belt my new 93 90 soon and just
> wondered how long it is estimated to do?  It looks easier than the I5
> engine in the manual but I don't know.  And are the special tools really
> required?  As long as I'm in there, should I change the seals (crankm, etc.)

I've done it on my '93 100CSQ twice (the first time I had the belt too
tight and it nearly self destructed).  On a 100, it's easy as there is
a lot of room.  On your 90, room is tight.  Now that I know the trick,
I can do it on my car in about 30 minutes!  Here's what I do:

1.  Remove all the plastic covers.  I would also unscrew the passenger
side standoff that holds the front plastic cover in place.  I nearly 
broke mine off trying to release the tension on the serpentine belt.

2.  Using a crow bar or similar, push down on the serpentine roller against
the hydraulic pump pulley.  There is a hole that will line up with the body
of the tensioner.  When they line up, you can stick a screw or similar in 
there to hold it in place.  Now you can remove the serpentine belt.

3.  Remove the tensioner (the big hex bolt in the middle).  Remove the
hydraulic pump pulley.  Now you should be able to remove the plastic
covers over the timing belt.

4.  Remove the 8 8mm hex bolts that hold the crankshaft pulley in place.
I made a mark on both pulley and balancer so that I was able to reassemble
them in the same orientation.  I bought a 3/8" drive for this.  The first
time I tried this, I tried an allen wrench.  I rounded out some bolts!  I 
found a 12 point socket (12mm? I don't remember), pounded over the head of 
the bolt bit into it enough to remove it.  Neat trick worth remembering.

5. Remove the bottom timing belt plastic cover.  Loosen the timing belt 
tensioner (another hex bolt in the middle).

6. Remove the belt.  You did remember to line everything up, right?  It 
actually doesn't matter if the crankshaft is 180 degrees off from the cams
since the timing sensor is driven off the back of the left cam. Being an
even number cylinder engine, everything is symmetrical!

7. You can replace the water pump and tensioner easily at this point if 
you want.  I replaced mine the 2nd time since the tight belt ruined them.
I'm not sure what's involved in replacing the crank seal.

8. Replace the belt and make sure the marks line up.  You'll notice that the
tensioner has a hex hole in it. You tighten the tensioner bolt (not too much),
and use the same wrench in the hole to tighten the belt.  Don't tighten the 
belt too much! The local Audi dealer said to tighten it enough so that you
can still twist the longest straight stretch of belt 90 degrees.

9. reassembly is the reverse of disassembly (or so my haynes manuals always
stated!)...

If you  have any more questions, feel free to send them my way.

-steve