92 740: timing belt moving forward!

Its a b230FT 4-cyl turbo. Well, I got the car running again by timing
it correctly. However, now the timing belt is not staying in the
proper position on t The pulleys, it is moving forward over the front
edge of the upper pulleys....I guess all of them, but that is the
points that I can see. I can see this because the upper timing belt
cover is not installed, only the lower one. So the belt is slowly
being eaten away on the forward side by rubbing against something,
possibly the crank sprocket. I have never had the crank pulley off to
see how the crank sprocket looks....but shouldn't there be both a rear
pulley guide and something on the forward side to keep the belt from
going forward or rearward? For some reason its like there is nothing
on the crank sprocket to keep it from going forward. I initally had
just the tensioner spring tension, and noticed it was creeping forward
on the pulleys/sprockets. So then I applied more tension above what
the spring provides....a lot more....and locked the idler down. But it
still is creeping forward. So now I will be ordering a timing belt
kit with new tensioner. This is about the third time I adjusted
timing on this car, and the first two times I didn't have this
problem. NOw that it is back from that disatruous 3 week stay with the
pro mechanic who couldn't get it running, it is doing this. Could they
have done something like improper assembly of crank sprocket that is
causing this? Or just my reassembly after timing technique that is
causing it?
The crank pulley is a bit wobbly...just a bit. by the way.


thanks, Geronimo

 

There are 2 guides on the crank gear 1 in front & 1 in rear these keep
the belt riding true it sounds like the front 1 is missing causing the
timing belt to rub

 

If the forward/rear crank sprocket guides are indeed separate, then
that must be what is wrong. I guess if one orders a crank sprocket,
tht is all you get...it wouldn't come with the guides? So I would
have to get it from some salvage supplier?

 

The guides are just a thin piece of mild steel. I saw this once before,
and the problem was the pin on the idler pulley bracket was not seated
properly in its guide hole (which was full of gunk). This put the idler
pulley on a slight angle.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Well, I suppose I could fabricate one from a real big fender washer,
and notch it for the index, if there is one....but isn't it cup
shaped, rather than flat?

 

I got the front end of motor apart. Found that both crank sprocket
guides are there...there is not anything wrong with crank sprocket or
anything, for that matter, that I could see, once old belt was
removed. The only thing I noticed is that the damper pulley was very
wobbly once the damper bolt was removed. I pulled it off, and find
there is NO key installed in the damper key slot!
How can the belt possibly move forward when both crank sprocket
guides are installed?
Now I have spent $75 for a gates timing belt kit, and if I install
it, the same thing could happen again, as I have not found a cause for
this.

Also, The timing belt kit kit came with a new idler/tensioner.
However I have no way at all to change the spring and its supporting
shaft over to the new tensioner. (At the ridiculous price of $75,
couldn't gates throw in a new pre-compressed spring, too?) I can't
release the pin keeping the spring compressed....and keeping it
attached to the old tensioner, as I have no way to re-compress it. I
need some sort of a compressor tool for this job. What...and where to
get it? Actually I wanted to install a NEW spring....but Rock Auto
doesn't have it. Thanks, Geronimo

 

Don't you have a U-pull yard anywhere near you? I have a scrap B21F
motor so I might even have those guides if you need them, I think
they're the same as those on the B230.

 

Yikes, what comes in that kit? Last timing belt I bought was under $20
as I recall.

 

Alll that comes with the Gates kit is the idler/tensioner and belt. I
could have gotten a kit for a lot less, but was in a hurry, and
O'reilly was the only place in town that had one. Some kit! NO
tensioner spring. I do believe that if I take the old idler/tensioner
with the still-attached and compressed spring, to Autozone, that they
have a loaner spring compressor tool, so I can get it switched over to
the new idler/tensioner. Guess I have to stick with the old
tensioner spring. There is no such thing as a u-pull-it in South
Texas, unfortunately.
You wouldn't happen to know how much the longest span on the belt
(the upper right) is supposed to deflect in the middle, would you?
That way I could at least check approx tension, because I would
imagine the belt is more prone to wander if not up to proper tension
from a weak spring. Still baffled as to how the belt could be moving
off the front of the pulleys/sprockets when both crank sproket guides
are installed! obviously am missing something. Thanks, Geronimo

 

I've never had to mess with it. I put a new belt on with everything
lined up and the tensioner bolt loose, turn the engine over one full
turn by hand and torque down the tensioner and it's good to go.

 

I got a new damper pulley key fabricated....that problem solved. It
is unbelieavable that that mechanic was so incompetent that he
couldn't figure out that that the timing had slipped way off because
the damper pulley slipped due to no key installed! He was clueless as
to why he was setting the crank timing per specs (to zero mark) yet
the car would not run!

A guy at work who used to own a auto repair shop didn't have a
clue how to change over the tensioner spring to the new
idler/tensioner pulley. I took it to Autozone, they have no tool to
compress/hold the spring while it is changed over to new pulley. Took
to OReilly's and they say there is no special tool for this, you just
use a vise. Well, how are you going to get the spring removed with a
vise when one of the jaws of the vise would have to be pushing on the
other side of the plate on which the compressed spring is pushing?
You have to have something like a miniature gear puller, with two
claws, and a nut to turn on the other end of the compressor tool, to
further compress the spring, and later to release it after
re-installation.

Upon looking closer at the old idler/tensioner pulley assy, the
pulley is fine, but its mounting plate is a bit bent up, the bends in
the platform / plate the pulley is on should be 90 deg. bends.... but
they are more than 90 deg. The steel is much too thick to bend, so
it really has to be changed. Could be causing a misalignment. So I am
dead in the water for now. I guess I have to take to an auto garage
and get a mechanic to do it?

Thanks Geronimo

 

I'd just go to a wrecker and get a whole new tensioner, in years of
working on Volvos I've never had to replace one, I don't know how so
much stuff got trashed on that car, '92 sounds rather young to me, even
though when I think about it, it is 15 years old. I've never owned a car
that new though.