Gear Set Up

[rush]

I have been studying the differential rebuild instructions and am wondering about the pinion gear setup with the ring gear. The TM makes no reference to the pinion to ring gear set-up like you have with a Dana style axle. Is this correct? It only makes note of the back lash adjustment with the adjuster caps.

[MasterYota]

Regardless of the make, its still a ring and pinion setup. If there is no point by point install reference, then I would measure the new pinion bearings against the old ones, re-install all the shims that where in the old setup, and then re-assemble following the instructions that are provided. I would be looking for an acceptable gear tooth mesh (pattern), and the appropriate backlash. Adjust the shims according to what you find. Thats about all that can be done.

If your still unsure, have a read through setting up other drop-out style differentials such as the Ford 9", Toyota 8" or Lancruiser diffs, or even the Gm corporate 14 bolt. While the specs will be no good, the assembly pratices might prove usefull.

A tip that I use when setting up gears, is to achieve a pattern that is deep and tight between the ring and pinion (within reason). I do this for the reason that both the ring and pinion want to move away from each other under load. The pinion wants to drive up and out, and the ring is natually forced away from the pinion. The bearings and caps all do their part to keep everything inline, but some movement does occur. If the r/p are set up just a tad tighter, when under load that movement will bring the r/p out to stock specs.
I've used this technique for several diffs I've assembled, and never had a problem with them; and thats under hard offroad useage, with big rubber, big power, and lots of gear reduction. I'm not saying its the only way, or even the correct way, but it works for me.

Good luck.

[rush]

Regardless of the make, its still a ring and pinion setup. If there is no point by point install reference, then I would measure the new pinion bearings against the old ones, re-install all the shims that where in the old setup, and then re-assemble following the instructions that are provided. I would be looking for an acceptable gear tooth mesh (pattern), and the appropriate backlash. Adjust the shims according to what you find. Thats about all that can be done.

If your still unsure, have a read through setting up other drop-out style differentials such as the Ford 9", Toyota 8" or Lancruiser diffs, or even the Gm corporate 14 bolt. While the specs will be no good, the assembly pratices might prove usefull.

A tip that I use when setting up gears, is to achieve a pattern that is deep and tight between the ring and pinion (within reason). I do this for the reason that both the ring and pinion want to move away from each other under load. The pinion wants to drive up and out, and the ring is natually forced away from the pinion. The bearings and caps all do their part to keep everything inline, but some movement does occur. If the r/p are set up just a tad tighter, when under load that movement will bring the r/p out to stock specs.
I've used this technique for several diffs I've assembled, and never had a problem with them; and thats under hard offroad useage, with big rubber, big power, and lots of gear reduction. I'm not saying its the only way, or even the correct way, but it works for me.

Good luck.

Roger, good info Masteryota .

I wouldn't consider myself a master by any means in diff set-up, but have tinkered on a few, GM 14 bolt full float being my favorite! The dodge set-up in the m37 is a little different. It has the normal bearing next to the pinion gear, and then a double bearing out by the yoke end. The inner bearing next to the gear and center bearing obviously take the thust loads in a combined effort. The manual does not mention any thing about shimming for engagement into the ring gear. (like danas do) And if you did shim the pinion, it seems that you would have to do it in two spots. Under the large bearing race and the double bearing race.

[pwdave]

take the caps & carrier off, put a straight edge katty cornered across the cap mating surfaces, with a dial caliper measure the depth of pinion face to your point and duplicate that. that will set the pinion depth into the ring gear, without this measurement being right the pattern will not set no matter what you do, Dave.