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Eaton Tru Trac, Motive gears 4.10’s in a 67 C10 housing.
Pinion depth set with T&D Machine pinion gauge. Pinion head called for 2.751, and 3 different areas of the pinion read 2.750.
Backlash set at exactly .0085. Motive says .007-.009 is spec.
The yellow compound was a tad thick, so that may be giving me a bit of and issue as far as pattern, but I did hook a drill to the pinion nut and ran it around 1,000 rpms to get the pattern.
Gears meshed nicely and didn’t make any noise running them with the drill.
IMO, it looks pretty good. Pinion shim may be just a hair too much (thrust contact patch closer to ID of ring gear), but I wouldn't mess with it. This is probably worth a 2nd opinion.
IMO, it looks pretty good. Pinion shim may be just a hair too much (thrust contact patch closer to ID of ring gear), but I wouldn't mess with it. This is probably worth a 2nd opinion.
I posted over in the 67-72 C10 and the general consensus is the pinion might be a tad deep (needs less shim?) but it’s in spec. It’s also only a toy, the truck may see 1000 miles a year so it’s not going to see a ton of use.
The question becomes how much shim to pull out if I decide to tweak it….003-.005?
I agree with it looking a blond hair deep, but not too bad.
When you spun it to check pattern, did you hold a hand on it for resistance or let it free spin ? (needs resistance)
Yellow paint too thick...add a touch of oil to it and mix well.
Iran the second pattern with the axles in it, no drag on the ring gear outside of that. I’m thinking some resistance on the ring gear should change the pattern a bit.
03-28-2024, 07:47 PM
4.10 gear pattern check! 
