Wiped out I-shaft bearings

[belchfire]

Something else I found on the "fire in the hole" engine was the I-shaft bearings are toast. The bearings are manufactured in layers and upon removal, it looked like there was a separation. The only thing keeping it together was the shaft itself. There was enough interlocking of the edges so that it didn't disentergrate but it's obvious that things were not happy. I noticed that the seal had a drip and as mentioned before, the cam belt was chewed in half (longitudinaly). So, How come? The crank & rod bearings are good enough that I will be re using them. Oil pressure has never been good when hot and I thought that that was causing my rattling lifters but new ones cured that. Are both brgs fed from the same gallery? BTW the holes were lines up properly so it's not that.

[rabbitman]

I think the belt will chew like that if the tensioner is turned the wrong way since it kinda pushes the belt into stuff. Clockwise is the way to go.

IM bearings have a hard life so flaking is common. Is it both or just the outer?

[belchfire]

The belt seemed OK for the first 25k or so then, surprise!  The IM shaft looks like it's the same as a gasser as there is the bump for the fuel pump (the block has a block-off plate too). This would drive the dist. as well as the oil pump. On the diesel, the vacuum pump and the oil pump. The turbo diesel pump has more poop so is going to put more stress on the shaft. I didn't think that it would be that much. Does this happen a lot or these just bad quality bearings? Didn't think that the tensioner made that much of a difference but if you say so, then I'll do it CW from now on.

[wolf_walker]

Overtightening t-belt kills most of those IM shaft bearings, usually show up as really low oil pressure at hot idle.
That big cogged belt really don't need to be overly tight.  Common mistake that has ruined a lot of perfectly good motors.
I drove a 1.6TD with 3psi hot at idle for 30K miles, it jumped to 30psi hot with some RPM.
It was badly worn out, the whole thing.  But it never quit and still turned in 38mpg@70mph.

[belchfire]

That does make a lot of sense but the whole reason for the rebuild was that the crank sprocket jumped a tooth. I'm going to try to fabricate a guide to prevent this from happening again. Rabbitman's suggestion on tensioner rotation might shove the belt further right and create more engagement.