Hello.  I recently picked up an 88 GL-10 turbo for 300 bucks and have been tearing into it for a couple weeks now.  Major issues were a cracked radiator, partially broken exhaust manifold and the infamous melted/shredded timing covers.

I removed the whole front end of the car and ditched the covers, noticing that the old (somewhat shredded up) timing belt had been riding over the inside edge of the driver's side cam sprocket by about 1-2mm. 

After replacing the timing components and dialing in the timing, I noticed that the belt is STILL walking off toward the engine!  Everything is in place properly (I've done this before and am totally sure of the procedure) and the belt looks bang on on all the other sprockets.

Is it possible that the head/cam was reassembled wrong?  It looks like the head gaskets have been done (excess sealant in some places), so I'm wondering if someone monkeyed up the shaft?

Any help or related experience would be great, and thank you ahead of time.

the crank shaft should have metal guides (discs) which align the belts.

Might have this backwards...

 

Too much tension the belt walks in

 

Not enough the belt walks out

the crank shaft should have metal guides (discs) which align the belts.

This. same withthe oil pump sprocket. Perhaps the crank sprockets are stacked in the wrong order, misaligning the belt

This. same withthe oil pump sprocket. Perhaps the crank sprockets are stacked in the wrong order, misaligning the belt

Could be.  It has been messed with before for sure.  I put the sprockets back on the way they were, but that could have been wrong.  Any obvious indications of which one goes on which?

The crank sprocket with dished area goes on first. The dished area is for seal clearance.

 

Check the tensioners for trueness. I had one that was bent slightly, caused the belt to ride off center.

Found it, I think.  Got under the car with it running, noticed some shaking at the oil pump sprocket.  Looked closer with the motor off and it looks like the toothed outer ring is off center from the middle of the gear.  Like when a harmonic balancer walks off.  Now, is it possible to find the sprocket on it's own, or do I have to buy (and replace) a whole oil pump assembly?