Differential Setup

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So Im setting up the new differential for my CVLX. Ford 8.8 Ford Racing Master install kit Ford Racing 4.10 R&P Torsen T2-R carrier So I discovered that this Ford racing kit came with the new design high torque inner pinion bearing and race first used on the GT500. Reading around about this, supposedly there is supposed to be a shim behind the race because the bearing is shorter. Then I read also that the Timken bearing and race used in factory builds needs the shim and the Koyo bearing supplied, shims up like the old style bearing. The kit did not come with any such shim regardless. My thought is that if the shim is missing and supposed to be there then the result would be that I would need a lot of shim between the inner bearing and the pinion head. Because whether the shim is between the housing and the race or between the bearing and pinion the end result is the same. So, Since I was unsure of if the shim was supposed to be there I didnt start with the .024 pinion shim that was on the 2.73 pinion and went with .035. After installing the pinion and then putting the carrier I adjusted the carrier shims to bring it to .011 backlash. Then I patterned it and got this. So I went back to the Ford racing install instructions and I must have misunderstood what I was needing to do to correct this pattern, so I added more pinion shim. I readjusted the carrier to .012 backlash and did another pattern. A lot worse. Im having trouble visualizing how adjustments in the shims change the pattern. The instructions have a pretty basic drawing of some gear teeth and Im not sure what side is which. So, Im thinking I should have gone the other direction with the pinion shim. Probably towards the factory shim. Am I right or am I wrong?
 
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Thats one of the jobs I leave to the experts (if you can find an expert) the difference between a happy gearset and one that dies young is not very much.
 

Colt45ws

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Originally Posted By: Rand
Thats one of the jobs I leave to the experts (if you can find an expert) the difference between a happy gearset and one that dies young is not very much.
Very informative.
Originally Posted By: Highline9
Add more pinion shims.
? The bottom picture is every pinion shim that came with the kit. I think it was like .080 total shim. If I need more shim then Im gonna have to find the shim that goes behind the inner race.
 
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When you lay your grease/marking compound on thick, it is hard to tell exactly what is going on. Drive heel, coast toe- need more pinion shim. 012-015 is preferred backlash, 008-015 allowable. Personally, on new ring-pinion installs I shoot for about 010-011. Nominal/starting pinion shim is 030. Clean off all that marking goop, take a new pattern with very little compound, with drag on the carrier. Worry about the drive side/convex side of the ring gear for now. You can stack shims on the pinion without problem. Not a fan of the thin carrier shims (I like the thick Ford factory cast iron shims). Hard to do without having a pinion depth gauge. I got spoiled in the shop.
 

Colt45ws

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Originally Posted By: punisher
When you lay your grease/marking compound on thick, it is hard to tell exactly what is going on. Drive heel, coast toe- need more pinion shim. 012-015 is preferred backlash, 008-015 allowable. Personally, on new ring-pinion installs I shoot for about 010-011. Nominal/starting pinion shim is 030. Clean off all that marking goop, take a new pattern with very little compound, with drag on the carrier. Worry about the drive side/convex side of the ring gear for now. You can stack shims on the pinion without problem. Not a fan of the thin carrier shims (I like the thick Ford factory cast iron shims). Hard to do without having a pinion depth gauge. I got spoiled in the shop.
I pulled a bunch of pinion shim out and it actually looks a lot better. I didnt take a pic, but I think if I tighten up the backlash Im at then it will be pretty close to good. Im going to get more marking compound tomorrow and reset it all. A little container came with the kit, but there was very little in it and it was drier than the Nevada desert so I couldnt use a paint brush like I had tried. I ended up using a screwdriver to kind of push it around. I started with the factory shims, but it was at 0 backlash with them. Also, really tight.
 
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Colt45ws

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So, to bring this back up. I Got some GM gear marking compound and revisited this after sitting untouched for months. After getting a pattern and comparing it to several places, I determined that I probably needed to move the ring gear closer to the pinion. I cleaned up all the existing compound and reshimmed the carrier, moving a .010 shim from one side to the other. This tightened up the backlash to .010 and moved the pattern from the heel towards the toe, so it was more centered, but now it looks really deep in the gear, which Im reading is the pinion being too deep. So I need to pull shim back out of the pinion. This is a relief and makes me want to actually work on it again. If I keep pulling pinion shim out, I may reach a point where I can use the factory cast iron carrier shims. When it was too tight with them, I had that pinion way in there.
 
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