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

Reply to
geronimo
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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

Reply to
Glenn Klein

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?

Reply to
geronimo

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.

Reply to
Mike F

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?

Reply to
geronimo

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 tim>ger>> Its a b230FT 4-cyl turbo. Well, I got the car running again by timing

Reply to
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.

Reply to
James Sweet

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

Reply to
James Sweet

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

Reply to
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.

Reply to
James Sweet

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

Reply to
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.

Reply to
James Sweet

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