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After 12 years of abuse a couple of teeth decided to come off the pinion of the old mule, not unusual with power and abuse over time.
So the L82 Kid wanted to test a spool so this is what he built in my shop. It will be interesting to see how it responds on the street but this is not a road car that will be driven more then 30 minutes at a time, more like 10 seconds at a time. He did a good job and got a nice pattern.
If you need a spool I would use a 12 over a 10 any day of the week. The gears are Tom's and for those that don't know they are special made since stock 12 bolt gears won't fit. This is matched to 1480 axle and 31's on the side. The Kid did a job I would use and I doubt the RG bolts are going to back out like some 12's I have read about in the past. If he doesn't like it I still have some of Tom's NOS 10-17 x 30 spiders and a new USA made bare case on my shelf he can use.
The best part was I didn't have to build it and just played ball with the dog.
Angular pattern, 2 cut straight teeth, lash is different for the 2 cuts, this looks like an DANA diff. Pattern is center on both the Drive and Coast, if it's spins smooth you are probably dialed in but check the lash for that gear set. Axle face shows chamfer still and light wear.
There are GM covers. Muskegon Covers, and Knockoff of Muskegon covers.
The GM covers are date coded starting around 68 if I recall correctly. The 63-4 covers had metal vents and a 1"-20 machine plug, that leaks a lot. The 65-79 had plastic vents and 3/4 npt plugs that work much better at sealing.
The Muskegon covers have thicker flanges and lower ears. The stock cover ears being thinner will snap off if the spring is not correctly loaded or you hit a pothole. The last I know of they are still made in the USA.
The knock off covers are just that, imported copies of Muskegon. I have seen issue with the holes not lining up or the side wall too close to the holes on the few I was given to use.
Gary, backlash measures .006-.007". How much torque should it take to spin the pinion yoke? This one seems a little light for having new bearings. It spins smoothly.
Last edited by RatRacer; May 23, 2021 at 02:32 PM.
book spec on pinion is 14-19, probably 15-20 plus 9-10 for the total preload. Spec is in the same ranges as the irons and will loosen up when the diff is broken in, that will drop to about 5-7
book spec on pinion is 14-19, probably 15-20 plus 9-10 for the total preload. Spec is in the same ranges as the irons and will loosen up when the diff is broken in, that will drop to about 5-7
The measurements are in in/lb. You need a 0-30 dial in/lb TW
My in/lb torque wrench starts at 20in/lb and that's about where it breaks over. My factory service manual specs 30 in/lb for the pinion alone, so I'm assuming it should be up around 40+ when spinning the carrier and axles.
Last edited by RatRacer; May 24, 2021 at 01:57 AM.
The old Mule gets a Spool
