While replacing the main seals on a B18 that was out of the car, I discovered that the timing gear on the camshaft had a good sized chip out of one of the teeth. I replaced it with another gear off of a parts engine I had in the shop. When I got the engine back into the car and started it, I noticed a noise that I initially thought was a wet belt. When I saw that the belt was dry, I thought it may have been a dry bearing in the generator or the water pump. I took the belt off, and started the engine. The noise was still there.
Is it possible that the used timing gear is making noise because it is wearing-in to a new crankshaft gear? Or is there something else I may have screwed up while putting it back together? Again, the noise is a constant kind of a "shhhh..." sound almost like a wet belt or gear noise in a transmission. It was a fiber gear, not steel. It concerns me, but I hate to have to take the timing cover off.
I would greatly appreciate any ideas or advice.
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1966 122s, 1968 142s, 1969 144s, 1979 245dl, 2001 V70 XC

Hello,

Do you reuse a stock front timing cover that uses a felt seal?

If yes, did you center the timing cover so it doesn't rub on the seal sleeve surface on the end of the crankshaft?

There is a special tool for this, but I don't have it, so I do it by eye and then use a feeler gauge to make sure there is clearance around the entire seal sleeve.

FYI, I sell machined timing covers that accept a modern lip seal and although centering is still important, I have my timing covers machined all the way through so rubbing on the seal sleeve on the end of the crankshaft is impossible.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

I used a cover machined for a modern seal that I had in my parts bin. I didn't know there was a need to center it. Perhaps I'll take a look. Do you suppose I'll be able to do it without removing the radiator?
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1966 122s, 1968 142s, 1969 144s, 1979 245dl, 2001 V70 XC

Do you notice if the machinist went all the way through or did he only machine enough to install the lip seal?

If he went all the way through, then the seal sleeve can't rub on the front timing cover.

I pulled the cover and observed that it had not been machined all the way through. I could also see that the rubbing had occurred at the bottom of the opening. Because the cover rests on the oil pan, I don't see how it could be adjusted downward.
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1966 122s, 1968 142s, 1969 144s, 1979 245dl, 2001 V70 XC

You can only really center the cover correctly with the pan off. Same with the rear seal housing.

Your theory about the noise is very reasonable. Although a replacement comes with the steel crank gear they aren't a matched pair so a new fibre gear can be swapped in if you're happy the crank gear is OK. What might be happening could be down to the amount of wear to the bronze thrust plate. This will have an effect on how the teeth run together. The old fibre gear would have settled into the wear pattern of the plate and the new one might now be tight or loose. Slightly tight would be my guess. With luck it could settle down after a bit of mileage. In the mean time I don't think I'd thrash it too much!