This is from one novice to another. Hopefully one of the experts will likely jump in here. I just set up my first set of new gears a week ago, but can offer an opinion.

The pattern does appear to be too much on the top face of the ring gear teeth. It would be better if it were closer to the flank. Adding shims to the pinion should move it.

It also would be nice to move the contact pattern on the drive side closer to the heel. That may or may not happen when you add shims to the pinion. (One source I looked at said that part of the pattern is not as important as the contact pattern between the face and flank and that one often can't obtain a perfect pattern there.)

Your backlash reading range seems large. The reading should be more consistent and not vary by .004. Take the reading near the heel of the tooth (as you appear to be doing) and try to eliminate all slack in your set up.

How is your preload, both on the pinion and carrier bearings?

 

Preload on the pinion is snug, about 20 in. lbs drag. Carrier preload is past snug and a slight drifting is needed to install the shims. Carrier won't come back out without some help from a wood handle to pry slightly. The BL is consistant when I rotate the gear and come back to the same tooth and measure again but does range as I said from .006 to .010.
Todd

 

Try adding about .006 to the pinion shim and try it again. Post more pictures. It looks like you are doing everything else right. Keep the pinion bearing preload consistant when you are changing ponion shims.

 

Here are the pics after the .006 pinion shim increase. BL was .006 to .009 this time.

 

Now it looks like it is a little too deep. Take about .002 out and check it again. Lightly oil the gears so that they are not dry. This will help make the pattern easier to red and allow the gears to run against each other easier. Always turn the ring gear against the pinion, not the other way around.

 

The orginal pattern needs about .003 LESS shimming behind the pinion gear. About a .031 shim should do it. The pinion gear is too deep. The backlash measurement should be scribbed into the side of the ring gear with Richmond gears. The backlash should not be fluctuating between .006-.009. While it maybe in 'spec', it sounds like you may have some runout in the carrier. As it warms up, this is going to increase. Or, you don't have enough carrier bearing preload and the set up is walking. I would think of changing the carrier. Also, Richmond is a fine durable gear set. They can be noisy. I don't install them in anything but strip/street race cars and 4 wheelers. I will always try and steer a customer away from them in a daily drivers.

 

Let us start again, I changed the tip on my dial indicator and used a little more finesse. The BL is .007 - .009 average. First pictures I used a .037 pinion shim and the second I used a .033 shim. Looks to me like the best I'll get is close to .037 which by the way sets the pinion depth at 2.455 where the pinion gear says it should be.


http://mysite.verizon.net/res1hxvw/037.jpg
http://mysite.verizon.net/res1hxvw/037coast.jpg
http://mysite.verizon.net/res1hxvw/033.jpg
http://mysite.verizon.net/res1hxvw/033coast.jpg

 

The .037 looks a lot better than the .033, although the pinion possibly could be a little deeper. If the .040 was too much shim, that doesn't leave too much room in between - unless you want to try .038 or .0385. If you can't find the right combination of shims for that fine an adjustment, I'd be tempted to call it "good enough."

 

It still doesn't look right. It's times like this that I wish I could get my hands on it. The coast pattern with the .033 shim looks deeper than the coast pattern with the .037 shim, which is completely backwards. If you have the time and patients try going .005 in both directions just to see what happens. I have been far enough off on the first try that I couldn't tell which way I needed to go and just had to take a big step in both directions. If you don't want to mess with it any more then try the .037. Don't be suprised if it is noisy.

 

Okay, after reading the replies I spoke with a machinist friend and he asked me why I was checking the BL at a point of the tooth which was not making contact. He said the BL should be checked at the point where the teeth make contact because the outer point of the ring gear travels farther then the inner point. So I checked the BL again and sure enough it is .002 less when checked at the point where the pattern marks are. My shop manual shows the dial indicator out at the outer tip of the tooth. Which should I go with? I want it to be as right as it can and I am in no hurry to get it finished.

 

I check them where you were checking it. I use a finger type indicator, which is easy to move around, but the plunger type is hard to set up in the right position. It just about has to be checked where you are checking it if you are using a plunger type indicator. Just be sure that it is set up so that the plunger is traveling in the direction of the ring gear rotation.