Hello All, I was in the process of cleaning my housing and replacing axles bearings when I discovered what appears to be a spun race. Based on the attached pictures what are your thoughts? I've had two people look at it locally and one says "install 2 new races and let it go" and the other said the housing needs to be replaced. Any input would be appreciated. Thanks
I have seen that before and just used new bearings. Might not of had enough preload on the bearings. Did the carrier slide out or did you have to work at it to get it out of the housing. They should be really tight and usually take a couple long pry bars to get it apart. Joe
It doesn't look like there's much of a spin that happened. If that's all that's wrong. I'd probably run it based on those pics. I'd also check out the rest thouroghly as well before deciding
The spin marks are just on the surface; there doesn't seem to be material removed from the caps or housing when checking by the "fingernail method".
If you have access to a good micrometer and a dial bore gauge, it would be easy enough to figure out what's going on here.
I would use a bearing retainer compound on the cap after it's installed and shimmed properly. Just clean the surfaces and put a little on. See the article below. Make sure the cap to housing mating surfaces are true and clean. Maybe a slight touch with a file. http://www.machinebuilding.net/ta/t0418.htm
I agree that it doesn't look that bad yet. I'd probably stick the old race in there about 2/3rds of the way, and torque the cap down, Tap the race with a hammer and block, and see if it moves easily. Do the same with the new one. Probably could get by with just the locking compound.
Take a center punch and put a couple of stake marks in the housing . Put new bearings back in and run it.
With the caps torqued @ 25ftlbs the I.D. is 2.893" on both sides. The O.D. of the P.S. race is 2.8915" the O.D. of the D.S. race is 2.891"
I did a test similar to that earlier. With the caps torqued (@25ftlbs) I attempted to slide in the race and it would not go. Then I removed the cap, installed the race and re-torqued. I could get some slight movement out of the race (rocking back and forth) but could not get it to move enough to rotate or slide out.
Set the preload correctly and you will be good to go. Read any GM shop manual with 8.5 rear axles for instructions on setting up gears. 1973 and up should do you.
There has been movement. I would take the caps to a good machine shop and have them use a Sunnen rod cap grinder to accurately remove .0005-,001" from the face contact side of the caps. This will tighten up the OD of the bearing and not distort the caps.
Case looks fine. I have taken a bunch of rear ends apart that looked the same. Wash the surface off with brake clean as well as the outside of the races.. All of that will disappear. Sent from my Moto G Play using The H.A.M.B. mobile app
I have tun worse than that, and forgot about it, until years after sold the vehicle. I once had a Dana 60 in a 4x4 rig that showed a spun pinion race. I ground two notches in the edge of the race, coated it with red Loctite, put it in, and staked it. I drove that rig that way for 215,000 miles like that. I sold it two year ago. It is still doing just fine. The carrier should not have slid out easily. Those bearings need preload. You might need to re-shim. On Dana axles I use a case spreader to make room for a tightly fit carrier. Once the spreader is released, the preload is set. On other axles, I tap the carrier in with a plastic deadblow hammer.
Thanks for all the great info. With a lot of your suggestions in mind I'm going to proceed with the rebuild. Before completely gutting the housing I stuck the carrier back in and torqued it down to check backlash. I measured .019" So I'm wondering two things - Is the backlash out of spec because of possible gear wear? Is the backlash out of spec because of not enough shim on the ring gear carrier side? (The carrier can easily be installed with all factory shims by hand)
My first question is how do you know that all the you have are all factory shims ? That seems like a big assumption.
What was it that prompted you to take it apart? Were the carrier bolts torques tight when you pulled it apart? I think they should have been 85-90ft lbs ish, or did you use impact and can't tell.
Not an assumption at all. I'm the 2nd owner of the vehicle and have known the original owner all my life. He's the kind of guy that never forgets anything. He told me the only rearend work ever done to the car were axle seals and a pinion seal back in 1998.
It's a 40 year old rearend that's never had anything really done to it. I took it apart initially to just replace the axles, axle bearings and seals. I removed the carrier unit in order to clean the axle tubes better. After removing the carrier I noticed some slight pitting in the carrier races along with what appears to be a spun race. Since the only thing left was the pinion it was logical to remove it and inspect the bearings and races too. They suffer the same issues as well.
The specs on the caps are 55ftlbs. The only time I ever use an impact on a rearend is to remove the pinion nut. I didn't check the torque when removing the bolts. Just used a 1/2" ratchet.
You might want to check with a bearing supplier as to what those races are supposed to be. The information should be available online. Also check to see if they sell an oversize race. Bearing retainer compound should work. From their site: Loctite ® 609™ Retaining Compound, Cylindrical bonding Loctite ® 609™ is a low viscosity, rapid-curing anaerobic adhesive that augments the strength of press fit assemblies or slip fit assemblies up to 0.005"in diameter. Adds up to 3,000 psi holding power. Recommended for parts that will need subsequent dismantling, i.e., retention of bearings onto shafts and into housings.
As far as the carrier shims, I will recommend a Super Shim from Randy's Ring & Pinion or a similar unit. I had sold many of these kits to local builders and even a couple Chevy dealer shops. https://www.ringpinion.com/b2c/ProductDetails.aspx?ProdID=8289 If your axles are 28 spline, this should be the correct kit. Instead of screwing with a sack full of factory shims, you just simply add or subtract shims in the interlocking shim shells. The light duty gear builders I worked with loved these! They're not that expensive. There may be a 4WD shop in your area that may keep a kit like this in stock. Another note. If the rearend has a lot of miles on it, take the time to put in a new gearset and bearing kit. The odds of going back together without a howling ring & pinion set are not in your favor.
Yep! We're on the same page brother. My rebuild kit is Yukon and I ordered the Super Shim kit as well. I've heard a lot of good things about it.
All the factory shims I have seen are one piece cast iron ground to the correct thickness, on per side. Here is a 1979 GM manual with the 8.5" rear axel. http://oldcarmanualproject.com/manuals/GMC/1979/LTService/04B/index.htm Your back lash is way off, .005" to .008".
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