Jerry,

I stock Motive and US Gears.

The first set of gears I installed were Motive, because US hasn't made a 4.10 489 case ring and pinion in 3 years.

The 4.10 Motive ring and pinion had a good pattern, but if I set the backlash tighter than 0.012" the pattern suffered. You told me you were running a manual valve body and wanted to run minimal backlash to avoid "clunking like the original third-member had", so you returned the new third-member and I installed a set of 3.91 US Gears (free of charge) which set up at 0.008"-0.010" backlash.

Several months later, on 9/12/10, you E-mailed me:
"I still get gear clash when anything other that full throttle runs. I'm going to go with a cope or a&a transmission this winter with stock valve body with a transgo shift kit (to minimize shift harshness)". You also asked "do you think i can get .06-.08 backlash to help the clunk,clash issues?"

I replied:
"Realistically, I doubt 0.002" tighter backlash will help. It will probably just result in gear howl. You may want to look into the condition of the internal parts in your transmission or driveshaft as ring and pinion lash seldom results in the degree of gear clash you describe."

That was the last I heard until I read this post.

I guarantee:
1. I installed US Gears. They are clearly marked "made in USA" and they have a small shield stamped on the ring.
2. Backlash was set 0.008"-.010". US Gear specifies 0.008"-0.012".
3. Pinion preload was 14-19 inch lbs rolling torque (which is stiff to turn). I also preload carier bearings (also stiff to turn). I do not set new bearings "easy to turn" because whey will run LOOSE when fully broken in.

All these specs are right out of any service manual or gear installation manual.

I would like to know:
1. Did you install any different drivetrain components like you said?
2. If so, what changes did you make (transmission, driveshaft, spool, axles etc...)?
3. Did the third-member I built howl?
4. If you still had problems, why didn't you contact me further?

Cass