Chevy rear differential BIG problem?

May 2021 4 105 Report

Chevy rear differential BIG problem?

Hello and thank you in advance.

I am referring to a standard Chevy 10-bolt, 1984, 3:73 gearing.

You know that king pin/bolt? The final one before you glue up the cover and fill with oil? The one that holds most everything together?

Well, the threads for that bolt have been eaten out. Also, maybe 50% of the meat of that area has also been removed. None of it was my fault or doing. My "repair" of over a year ago has failed. The repair consisted of a slightly larger bolt rammed into the not-so-threaded shaft bathed in JB weld (i cleaned it as much as possible beforehand) I do not have welding experience nor such tools.

This is my DD and i need to roll. I do not know of the status of this issue as i will crack the pumpkin (Nov. get it?!?) tomorrow an get an assessment in the morning... it is 7pm now and will be rising/getting to work about 8/9 am tmw.

I DO know, however, i will have steel flakes in my gear oil. Sounds like a breakfast for a robot.

Anyone have a better plan than the one stated above? Because that is what i must do, again.

No time to junk yard a gear set, nor time to install. Not going to a "shop" (that's who hogged out the threads). Only thing i can think of is trying to tap the shaft and fitting a bolt with blue threadlock. Or more JB weld. Any ideas? I need to roll. Thank you!

Update:

Thanks for your advice. I know i should have gotten a new RE before now, but of course i want a 3/4 ton set...but they run about $1,000 a set around here...and then my tire won't fit it...gah!

Cars & Transportation / Car Makes / Chevrolet

apoorapothecary

Verified answer

Have you thought about getting a heli-coil insert for the hole? Clean the damage out, and run a heli-coil repair. It should be strong enough to work fine if the repair is done correctly. You should be able to get such repair kits at an auto parts place. Just take your time. If you are going nuts with jb weld, it'd probably have been better if the whole repair was re-tapped, rather than trying to wet-insert jb weld on a bolt! That, plus I've had some better success with the jb weld epoxy that comes in the roll, rather than the more liquid-y standard jb weld. It cures very quickly (not that I'm recommending that over a heli coil).

monkeyboy

I don't think you nor the shop understand how that "bolt" works. It's very common for idiots (not you, whoever did the work before) to break off the bolt. It is ONLY threaded at the head.

With the metal gone, this isn't going to work. That shaft wants to spin (it's called the pinion shaft BTW, the gears that it holds in place are called pinion gears, not spider gears as most everyone else calls them) and that bolt is all that keeps it from rotating. If there is not enough metal to have a bolt thread in there, nothing is going to keep it from backing out, and when it does, it will shear off, your rear differential will come apart, and it will destroy itself in milliseconds.

You CAN NOT just swap differential carriers in these axles. You can TRY, and you MIGHT get lucky and not get any gear howl, but it's not likely. The gear mesh is set with shims based on the gears AND the production tolerances of the housing and the differential case. Not often are those the same between two rear ends.

10 bolts are not worth anything, particularly truck ones. You had a year to get this taken care of, you squandered that time/money, and now the solution is to buy a used one off craigslist for $150. Half ton rear ends of that vintage are not very strong, and no serious off-roader wants them. Demand is down, supply is still there, thus they are not worth much.

Mark my words...spend the time, effort, and money trying to make a broken piece work, and you will be utterly disappointed. Spend the money to do it right (replace the whole thing) and you will be back on the road in no time. Everything you know is good in your rear end (brakes, axleshafts if necessary) will swap over to another 10 bolt the same vintage, so don't even consider another option.

goto the wrecking yard and buy a new carrier.transfer your ring gear as well as the internals.basically your gonna buy a pumpkin.pop the axles out,and the 2 bearing covers and the whole assembly should be in your hands.its not model specific,just the old 10 bolt.