I recently built a 385 stroker and put a Pro Form noisy gear drive on it, the thing that I have noticed is that at idle I can hear a tapping noise coming from the timing cover area. It almost seems like the reverse idler gear is bouncing back and fourth and maybe I am hearing it hitting the timing cover!? Is this normal? I set all my clearences up correctly.

Befor you pull it apart, check the balancer, they will hit the cover sometimes.

they can rub on the block and they can also rub on the timing chain.

Well I checked and the balancer is clearing the timing cover just fine.
I think Brad must have been drinking when he said it can rub on the timing chain lol.

I have another question for ya Brad, how do you turn your URL into a hyperlink on this particular message board?

haha I ment cover but Marty already said it so it doesn't matter ;)

Well I guess I'll just drive it and hope its fine :rolleyes: I love the gear drive whine, but the tapping sure drives me nuts.

Do you have a cam button on that set up?? My car had a P/J gear drive on it & it needed to have a button installed even with the hyd. cam...

If you put your finger on the timing cover can you feel it tapping on your finger??


Just some food for thought graemlins/thumbsup.gif

It has a thing called a "thrust bearing assymbly" it goes in the center of the cam gear and out towards the timing cover with a small clearence I cant remember like .005" or so. Is that the same as a "cam button"? I will feel the cover for a tapping tomorro, good idea!

What kind of cam are you running ?? I made the mistake of putting a cam button on a hyd cam, with a double roller. graemlins/clonk.gif It also is tapping the cover(sounds like a cowbell). When I put my finger on the cover, I can feel it hitting & the sound pretty much goes away.

I think I'm going to tear it out of there. BTW, It didn't make any tapping noise with the gear drive in it...

Its a 268XE hydraulic :rolleyes: You would think the directions would say not to use it with a hydraulic cam, maybe they just made a mistake.

Hopefully someone a little more knowledgeable will chime in, but I think that you do need to use that thrust bearing with the gear drive setup, I just wonder if it needs to be shimmed to take out the slack. I was told by comp cams that a hyd cam can move front to back by as much as .08" & with no chain on to hold it back, you need to run the thrust bearing. But if there is slack in it, how can it not hit the timing cover??

I don't know, just thinking out loud....
Please let us know what develops of it, like I said I am toying with the Idea of removing the button from my car, just can't stand to hear that niose! graemlins/thumbsup.gif

I haven't fired mine up yet, but my Edelbrock gear drive cam with a cam button. I'm useing a hyd. cam and installed the button since it came with the gear drive and it was in the instructions.

Originally posted by ssal396:
I just wonder if it needs to be shimmed to take out the slack. I was told by comp cams that a hyd cam can move front to back by as much as .08" I actually even shimmed the thrust bearing out, I went and found a stainless washer and ground down the O.D. so it fit in the center of the cam gear behind the thrust bearing, which gave me the proper clearence. I can see a cam moving back and forth, but this tapping noise is always there and is very rapid, I have a hard time believing its the cam moving back and forth. It sure seems like it is the reverse idler gear and the excessive clearence that I was supposed to use with it. Im just gonna leave it like it is, if it actaully breaks some day I'll tell ya lol