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Wanted to get some input my gear pattern. 2 series 3.73 motives orange box. I put in a pinion spacer and the best preload I could get before the next .002 shim was 20in lbs turning. Going down by 2 thousandths spiked the preload to almost 40in lbs
2.291 pinion depth (2.292 was etched on the head). Factory carrier had no shims besides the thick plates at each end of the outer race. Factory pinion shim was .028, new set needed .033 for 2.291. I put reinstalled the carrier with the motive ring gear with the same thick plates on the same side and no shims, backlash came out to .0065 so I moved on to the pattern and this is how it came out. Might have to recheck with thinner paint, I tried to keep it thin but looks thick in the pics
To go from 20 in.lbs. to 40 in. lbs. is not a large jump. And if they're new bearings that 40 in. lbs. will diminish very quickly as the bearings wear-in (which they're supposed to do). The contact between the race/rollers/race still have to establish their relationship to each other and as that is occurring,preload lessens. I've had preload go to 0 after use/mileage.
First couple Qs' on the pinion, new bearings ?, by 'pinion spacer' you mean the solid spacer not a 'crush sleeve' ?.
Yes, marking compound/paint too thick. Too much will smear and cover the true pattern.
Pattern seems centered so backlash looks good but being the pattern is at the edge of the tooth, seems more pinion shim is needed.
I would re-mark thinner as everything currently is and see the pattern. And more importantly, don't look at the marked teeth, look at the carried-over marking paint on teeth that were bare to see a true pattern.
To go from 20 in.lbs. to 40 in. lbs. is not a large jump. And if they're new bearings that 40 in. lbs. will diminish very quickly as the bearings wear-in (which they're supposed to do). The contact between the race/rollers/race still have to establish their relationship to each other and as that is occurring,preload lessens. I've had preload go to 0 after use/mileage.
First couple Qs' on the pinion, new bearings ?, by 'pinion spacer' you mean the solid spacer not a 'crush sleeve' ?.
Yes, marking compound/paint too thick. Too much will smear and cover the true pattern.
Pattern seems centered so backlash looks good but being the pattern is at the edge of the tooth, seems more pinion shim is needed.
I would re-mark thinner as everything currently is and see the pattern. And more importantly, don't look at the marked teeth, look at the carried-over marking paint on teeth that were bare to see a true pattern.
It is with new bearings and a solid spacer. Well I don't have the tools too remove the pinion while saving it, because it is the new Timken bearings. I do have a 20 ton press from when I did bushings front and rear, maybe I can get the big bearing splitter and set it up some how in the press but from what I could see, the bearing splitter would push against the rollers in the cage and not the race and I'm afraid it would damage the cage.
Also do you think I should drop down .002 on the solid spacer go back up to 40in lbs for preload? All the preload numbers I came across in the forums for new bearings range from 15-30in lbs
Is the pinion depth number more of a guide then if I need to add a shim for deeper tooth contact? It seemed you to make sure no mater what stay at that depth because it is etched into the head, + or - .002
Last edited by Dark_Side; Apr 27, 2021 at 07:09 PM.
The pattern is different and true with the thinner coating. Before it looked like the pinion needed to come out (add pinion shim) to go further into ring gear, now it doesn't and looks good as is. I would run that.
Pinion depth number is based on the gear manufacturers setup/fixture. Any variance in the rear ends' housing dimension may necessitate going away from their recommended dimension.
Even your new thinner coating is too thick but irrelevant since you established a good pattern. All the pattern threads I participate in, I'm always recommending thinner and observe the unpainted teeth.
Last edited by FirstYrLS1Z; Apr 27, 2021 at 07:49 PM.
No not yet. I work 10-12hrs driving 450 miles a day for FedEx freight so not much time during the week. I got the diff cover on and gear lube in though. I think I'm going to spray paint it so the red umi sway I just got will contrast real well with it.
Finally got it all finished up Saturday. It passed the test drive with no issues. I might hear a small whine but only right in between the accel and decel.
Here is some progress pics of putting it back together
I like the white of the springs contrasting with the black of the housing.
Thanks, ya they were pretty rusty for only about 3yrs old strano springs and sprayed them with flat white cause it's the only white I had. I thought about the blue can I've got but figured it would be easier with the white
3 years ago, 2018, I had the complete rear out to make room to make easier replacing all the rearward brake lines. The hard line just before the flex line that jumps over to the rear end rusted thru. I acid cleaned the springs and POR-15'd them.
At the time the 3.23 rear end came out after a few years of use and the 4.56 rear end was going back in.
The rear brake line project was I converted all the hard lines to -3AN with 3/16 stainless steel tubing. No more metric bubble flares and tiny OEM double flare fittings.
Last edited by FirstYrLS1Z; May 3, 2021 at 04:05 PM.
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Gear pattern check 
