atb

Any thoughts on this? All help appreciated.
This is from the OB track car ('79 4.5L). As can be seen, the tensioner pulley sits closer to the engine block than the crank gear. The shoulder bolt has the thick washer on it, and there is a snap ring behind the pulley.
Any other guesses as to what needs to be done to get the pulley over the crank gear?

Lizard928

Bent sholder bolt.

atb

The bolt looked okay (straight), but maybe it doesn't take much.
Any other possibilities?

Here's what it's doing to belt alignment on the cam gear.

Mrmerlin

the tensioner roller is tilted slightly forward ,as Colin mentioned a bent shoulder bolt ,
it can also be the bushings on the tensioner arm and the tensioner roller bearing may also be worn and it tilting,
this drives the belt into the rear of the harmonic damper and eventually wears down the belt till it fails. If you pull out the pivot bolt and if there is any doubt of it being bent replace it .
this condition usually stems from an overtensioned belt

Lizard928

I would replace the shoulder bolt, and bushings regardless.

Or go to a porkensioner.....

Tom. M

Is this the one you got from Ken? If so, then both the first and second bolt are bent? Or is it possibly a worn crank gear keeping the belt riding forward? Could the boss on the water pump be a cause of the misalignment?

atb

I don't really see a tilt when looking at the roller, part of that may be the off- angle of the camera shot. It IS very clear that the entire pulley looks like it needs to come forward about an eighth of an inch so that it sits direclty above the crank gear doesn't it? Even if the belt were running on the very back of the crank gear, it would still be overhanging off the front of the pulley. I guess I should double check that the crank gear is all the way back on the crank snout.

Dave928S

So would I. Had exactly the same misalignment problem on a friends car .. shot bushings and slightly bent bolt. I think that shoulder bolt, with its stress concentration at the step, is a design weakness anyway ... and it's a use once item.

Stromius

Any chance Adam the cupped washers are missing on the crank gear?