Cam gear change question Harley Engine Discuss Cam gear change question in the Harley Tech & Harley How-to forums; I just completed changing my twin cams from chain drive to gear drive. It's running fine and I don't hear any winning sound but I do hear a clicking sound ...

I just completed changing my twin cams from chain drive to gear drive. It's running fine and I don't hear any winning sound but I do hear a clicking sound now that sounds like a tappet nocking. Can any body tell me what might be causing that and if it will hurt any thing. I can live with the clicking as long as it don't damage any thing. Thanks for any info.

[Buzz Kanter]

When do you hear the sound?

All the time, low revs, high revs, hot, cold or always?

[shovelmike]

Excessive backlash in the gears can sound like a lifter but I don't think it could damage anything. Did you use adjustable pushrods? Make sure adjustment is right. If it is a lifter problem it would be easy to change if you have the quick change pushrods.
Let us know how it goes. Ride safe and God bless. Sincerely: Shovelmike.

[JCourneyaP]

If your a running a hotter cam you will hear a bit more knock. How many miles on the motor before you changed the cams? Using the same tappets?

I used andrews gear drive with stock twin cams, new lifters, and adjustable push rods. The clicking starts after the engine warms up. I followed all the directions to the letter. I just want to know whats causing the clicking and if it will hurt any thing. Thanks for any more info on the subject.

[evoKENevo]

Andrew's gear-drive with STOCK twin-cams ???

I meant there as close to stock that Andrew makes.

[evoKENevo]

OK..assuming all else was done right (which is further than I've gone with a TC engine) I'd suggest (as others have) that you go back and readjust your push-rods...noting it's not hard to lose count of the adjusting nut flats (six per full turn) and you may be just off (loose) a little on one or more push-rods. Or,it COULD be that you did'nt allow enough lifter bleed-down time between adjusting other push-rods and/or starting your engine,etc..and bent one a bit. The latter of which would,in effect, shorten it that much..possibley repairable if done carefully.

And,uh,yeah....I "done-that",my 1st time..duh !?!

[shovelmike]

Originally Posted by crzrlou

I meant there as close to stock that Andrew makes.

Which cams did you use? Andrews made a TW12G which is very-very close to stock, but they evidently only made a limited number of them and they sold out quickly. Were you able to get a pair or did you move up to the TW21G's. Those are higher lift and longer duration...a little more noise but very worth it. Torque, right where I need it.

I checked my push rods and I found that I had forgotten to tighten one of the pushrods locking nut. Lucky I didn't run it very long. After I corrected my dumb mistake it runs great now. Thanks for all the advice.