Hi,
I'm installing a gear drive in my '02 TC and now have the cams installed in the cam plate. What I'm seeing at this stage is a very minor amount of interference during about 3/4 of the rotation. Based on the S&S instructions they say to measure the backlash after the plate has been installed. From my perspective I really can't see how I could measure .0005" of backlash while trying to hold the cams still.
Does anyone have a better sugestion for measuring backlash on both the inner and outer gears? Somehow I think the inner gears is a feel thing of whats right. I'd like to hear back from anyone who has had experience doing this. Thanks.
I tried like crazy to measure the cam gears, installed, to the gear, and I think I wound up going through the lifter hole to the cam lobe. I finally got the magnifying glass out and looked for movement on the outer. Most popular dial indicators are going to show increments of .002, so if you have slight movement, on one gear while holding the other, you have clearance. However you do it, check in 4 places, 90 degrees apart.You will rotate it several times to center the oil pump,(use evo lifter block centering screws to center) so recheck it then.I think you are speaking of interferance with the cam plate in your hand? If so, you can't judge by this. The other end of the cams must be centered for an accurate assesment. Also, you could bolt a small tab to the driven cam, and measure that way, but becareful of the bolt length and how tight you tork it- I did not do it this way, but think it should work. Think it out b4 you do it! Are you changing the inner cam bearings? I am a mechanic, but not a pro bike mechanic, so consider this a suggestion. Has anyone told you how much noise to expect? Wines a little,but not bad. Good luck, and check it twice. And then again.
If you can feel this condition of interference just rotating the cams in the support plate the center to center is off on the bearing bores.They should spin easily.Your plate could be warped also.Check the plate and the center to center distance,if your inners are tight your outer gears will also be in a bind. S&S makes smaller outer gears but you have to buy them separatley. You should probably replace the cam support plate.
Pancho -I will check the warpage, thats something that I should have done since the support plates are known to warp. I don't see any specs in the manual for CTC for the bearing bores; do you happen to know it?
Also - not to confuse the situation the cams do rotate freely in the support plate but I feel metal to metal contact through much of their travel.
94 -I do have the Jims tools to replace the inner cam bearings. Some of your other thoughts should help when I get to the end. Your comment about the gear whine interested me. From what I've heard if it clicks its likely too loose but won't do any serious damage. If it whines a lot it is too tight and needs to be corrected. That said I'd rather get it right up front.
and whines a lot is the key- it will whine some even correct. not annoying, but you will hear it. you are well on your way. what cams did you select? are you reusing the original plate? just curious...
The cams I'm using are Headquarters HQ0039. You can check the specs on their website at head-quarters.com. I plan on reusing the plate unless I find a problem with it. I do need to check the warpage.
I did the top end last winter including porting, larger valves, springs, ignition and 9.5 pistons. I ran it with stock cams last year as I didn't have either the cash or ambition to go further. So naturally this year I had to finish what I started.
I know I read somewhere that Harley had some issues holding the tolerances on the support plate center to center. It may have been Andrews. Near as I can tell I'm coming up with 2.030 for center to center.Wish I could give you a definite answer. I think harley also used color coding on thier outer gears to adjust for the tolerance.When you say metal to metal do you mean like it's scraping something or you can feel each tooth as it contacts. I checked my gear to gear lash at the cams by just holding one cam gear and moving the other turning it every 90 degrees to check it in four spots. You should be able to grab one cam and spin it like a top with two fingers.Mine went together like that and had .001 backlash on the outer gear set. The whine is just audible at idle and makes a sweet sound under power.S&S can give you the answers you're looking for.
I recently had to check the gear lash on a set of S&S 585g cams.
The inner cam to cam gears were impossiblt to get to behind the Fueling cam support plate that was being used.
I found that using the little 3/8" long battery bolt spacers installed between the support plate and the engine case on every bolt except the ones with the hollow locating dowels allowed the inner cam bearing journals to enter the inner bearings by about 50%. Plenty enough to hold them in place for lash measuring.
I only snugged the bolts to hold the plate in place so as to not warp it or strip threads in the case.
This gave me plenty of room to get at the gears and measure the lash with a .0005" dial indicator.
Hopefully this info can help anybody else dealing with this difficult access issue.
The problem with measuring lash off of the cam lobe is the movement at the lobe will be different than the actual movement at the gear teeth.
You are right, if not done carefully. I rotated the cam so as the flat, or the ramp, was my point of contact. Then moved cams only enuff to check backlash. In this short amount of movement, all you get is the backlash. Any further and you get leverage. Great idea on spacing the plate out. That's a much better way.
Checking back lash in a TC gear drive 
Linear Mode
