Jim_H

I know the passenger side (1) gear needs replaced. I am thinking of replacing the drivers side (2) because I am SC'ing and don't want to worry about what's going on and there is a little wear starting to show in the middle.
The oil (3) and crank (4) gears I could use some input on. They are not sharp but are shiney. I believe they are cast? Thanks for any input!

Bill Ball

Either the photos just don't show it or I am blind to what you consider wear. When the aluminum cam and oil pump gears lose the annodization, which usually begins in the center, the tops of the teeth get polished VERY shiny, develop dishing and sharp edges. I cannot see any of that here. You say they are shiney, but it does not show - must be the angle. The wear looks amazingly even. True, if the annodization is gone, wear can progress rapidly, so I get your concern. These just look too good to replace.

Your oil pump gear appears to be a steel replacement, judging by the rust on the front face. The edges of the teeth look rather nicely rounded and I see zero dishing. Even if it is the original aluminum gear, it looks fine, although not the right coloring. The steel crank gear looks good too. Let's get a few people with more sensitive eyes to agree or disagree..

JP Rodkey

I don't get it either. I've recently seen some bad ones, and yours aren't even close. If they were mine, I'd keep them and sleep like a baby.

Jim_H

Thanks Bill. I tried to take the pics at an angle so the flash wouldn't reflect. I may need to take more pics.

Bill Ball

Please do. Now, it could be your belt has been so perfectly tensioned that the wear pattern is even. If so, I would leave them alone.

Oh, I said the oil pump gear was a replacement. It would be for my 89 which had an aluminum gear from the factory. Yours may be an original steel one - I'm not sure when the factory changed over to steel. Still - looks good.

UKKid35

If the red marks are the 45 BTDC indicators, why are they so far from the TDC indentation?

FlyingDog

Just out of curiousity, is seeing any silver on a gear bad? I have a used oil gear with a little silver to replace my severely grooved and shiny silver gear. Is that a bad thing?

SharkSkin

The one in the first pic seems to have some exposed aluminum -- white metal color. If so, ditch it. The second pic looks OK, but check all the way around. If the anodized coating seems thin, or is broken through in spots, you may want to replace it. But from that second pic, I can't see any obvious thin or worn spots. It may be OK.

Big Dave

Uh....here's a BAD cam gear...I wish mine looked as good as yours!

Mine are visibly dished....they slope down toward the middle of each tooth.

Bill Ball

I had some wear on my oil pump gear, like you describe. It wasn't bad. I left it until the next TB change because I didn't have the part. It held up well despite the fact that my belt was apparently over-tensioning, as I had quite a bit of wear on new cam gears (which actually left me wondering if the current annodization is not as hard).

The rule is that wear is rapid on the aluminum gears after loss of annodization, but if the belt tension is not set too high, the gears will wear slowly.

The problem with the oil pump gear is that it can't be inspected when you retension the belt every 15K miles. The replacement oil pump gear is steel, which is less subject to wear.

So, this boils down to a WYAIT question. If you changed the TB a while back and noticed the slight wear on the oil pump gear, but left it alone, don't worry about it. If you are getting ready to do the belt and see wear, change it.

atb

Jim,

Man, those gears are toast. Order up some new ones dude. Hey, since your old ones are done anyway, do mind sending them to me. They would make some nice paperweights.

Fastest928

Replace the cam gears // once the anodizings wears off, accelerated wear will occur.

Also, alwyas good to use 1 red mark on the left, two on the right and three on the crank gear .. just to be sure

Marc

heinrich

Passenger gear needs replacement.Others are just fine.

borland

If you change the cam sprockets as Devek suggests, your in for removing the valve covers and doing a cam timing adjustment as well.

I'd say your car will go safely many miles without replacing them. Just make sure you use the belt adjustment tool correctly.

Fastest928

No, you can transfer the position of the timing gear to another gear by using 5mm screws and carefully noting their position and swapping gears. Remember, the spyder is fixed on the cam!

Marc