Continuing with my rear end rebuilding project - much delayed by the holidays and my wife's broken ankle. I got 10 new old stock ring gear bolts. Still in the box. My question is, do stock bolts use lock washers? (My rear had been previously rebuilt with non stock bolts, using lock washers.,

 

Send a PM to GTR1999. He is the go to guy for all things "rear". Jerry

 

Hi Guys,
The original ring gear bolts used black hardened lockwashers from 63-late 76. These worked pretty good for the most part, at times the bolts backed out but when GM transitioned from those bolts/washers to just a flanged head RG bolt by 77 it became more common to find RG backed out. They were not loctited in position, just torqued and if someone didn't get the torque right then they came out.

Now if you have NOS RG bolts, that's all well and good but I wouldn't use them. I would spend the $35 or so and get new ARP from Summit and use them with Loctite #271. You have to make sure the case RG holes are countersunk so the ARP's fully seat or they will back out. That was an issue with the 12 bolt failure posted here last summer.

The common master kits are not offering the best parts today. They do have USA Timkens but the RG bolts are common fully threaded gr 8's and common lock washers. Will they work, yes, will they work as good as ARP or originals? In my opinion no and I never use them. I have years ago but any performance build should use ARP's. If you want to go to the nest step call Mark Williams and get their drilled RG bolts for safety wiring. For the majority of vette builds they are not needed but they are nice RG bolts and were offered from Tom as well. They have MW etched on them.

Looks like you decided not to polish and tune the posi?

 

I pulled a rear end out of parts C-3 last year. It had been rebuild in the past and probably half of the ring gear bolts had backed out about 1/4 inch. Luck for who ever that they parked the car for some other reason. I used Gary's advice and went down and bought ARP bolts and lock tighted them.

 

Did you do any machine work to the carrier in order to install the ARP bolts? Unless there are different types of ARP bolts for this application, I believe Gary says the ARP bolts are not a direct replacement for factory bolts.

 

400 lb springs and plates installed

Casting crack - eliminated by grinding

Magnafluxing carrier

Gary - Thanks for the bolt info. Obviously what I'm doing here is nothing like one of your rebuilds. I have ground and polished the edges of the 2 carrier openings. I reinstalled the spider gears, adding .008" shim thickness behind both large spider gears. I installed new 400 lb springs and plates. The ring gear is in place, but not bolted yet. That's what brought up my question about bolts.

 

Yes, Gary had a link with pictures of what he does when rebuilding a rear end. I had my friend who is a machinist touch the bolt holes up at his home shop. I'm not going to speak for Gary, but you are trueing up the posi carrier bolt hole faces to make them perfectly perpendicular to the ring gear. so they 100% contact when Tq'ed into place. I used red Loctite.

That rear end I pulled. The loose bolts were about finger tight. The ARP bolt threads are tight just to install. Gary polishes the mating surfaces all true for a mechanical bond without micro gaps.

The posi unit gets torqued in both directions while driving and it works the bolts out over time

 

OK. Thanks for the info.

 

A lot of the posi flange RG bolt holes are sharp edged. The ARP RG bolts are 3/8-24 with .800" underhead length. They are for the 12 bolts and work on the corvette as well. I think they are 3001 but you can easily find them on summit, jegs, or direct on ARP's site. They have a small radius under the head that adds strength where as the grade 8's are square shouldered. They are also fully threaded and both GM & ARP have a should for better fit in the holes. All you need to do is get a 82* 3/4" countersink and cut in a small countersink so the ARP radius will not hit it and the bolt can reach full torque.

Here is a hole in a cleaned up stock case




Here it is after I touched it with the countersink, just in a hand drill.This is not a machine shop requirement.



ARP & GM RG Bolts. ARP offer full thread engagement



Checking bolts on comparator, now you can see the radius under head.

 

OK now I understand about the ARP bolt installation. Thanks again Gary and gkull. I will update this as I go along.