Britt2020

iTrader: (7)

I am starting a project to see how ridged I can make a 10 bolt housing. I have an idea of what I would like to do, but am also open to ideas. My idea is to fab up a tapering gusset from the center section out to about 1.5-2'' short of the bracket.

Any ideas are appreciated.

01ssreda4

iTrader: (96)

Somebody makes a bolt on kit!

Britt2020

iTrader: (7)

I'm aware of that, however it's not what I'm after. I keep reading that tube flex is the cause for most 10 bolt failures, but I am having trouble wrapping my mind around the chain of events that lead up to the failure. Any insight is appreciated.

I'm not looking for a "kit". I'm looking for input from people that have real world experience. Or if you don't have experience with it, but still have an idea of the cause I would still like to hear about it.

SladeX

Tube flex is just part of the problem. You can weld up the tubes completely and it may still grenade on you. (they are only tack welded a few spots)

The Torque arm puts a lot of stress on the housing itself. It's similar to the 12-bolt problem and 6 speed combo except because of the smaller size even an auto may grenade a 10 bolt. During a hard launch, the housing distorts a bit and deflects the pinion a bit. This is evidenced by the eventual pinion seal leak all 10 bolts seem to get.

The size problem really hits hard though the most. If you have an auburn, you may shear the spider gears during hard accelerations and turns (worm gears for torsen), if you launch hard 3 points of issue is axles breaking (some tube flex), ring and pinion (case flex alters gear contact pattern). If you auto cross, the c-clip is a weak point. All in all, its just too physically small to handle the forces applied to them on a continual or repeated basis. Add in the 10+ year age for the newest of 10 bolts and you are on borrowed time.

Britt2020

iTrader: (7)

So where you're at is that housing warp caused by the tubes/TA and over all insufficiently sized everything...I'm smellin what your sellin.

I wonder how or who rather, could test the breaking point in ft/lb of the running gear? Ever heard of this being done have any ideas of who could do it?

DANOZ28

iTrader: (1)

i will try n dig up an article i have on beefing up a 10 bolt. not that you can make it indestructable. welding the tubes is something they do however im not sure exactly what or how. (i will edit later)

ponchjoe

I believe High Perf Pontiac did an article on how bolster the 10 bolt, I will see if I can find it.

Britt2020

iTrader: (7)

I have read several articles on the topic. Seems like are more focused on adding different internals and such. My main concern at this point is finding the stress areas in the housing and tubes and mitigating as much movement of those specific areas as possible. I'm not looking to make one "Bullet proof", there is no such thing in the automotive world.

First step of this process has to be identifying the high stress areas. Above someone mentioned the TA mount as a potential stress area and I agree. I have a few thoughts on how to correct that. As far as the axle tubes go, I am in a rut.

As far as the strength of the R&P goes, there has to be someone out there with the ability to test how much energy it take to cause a failure without the added warp from the TA and tubes.

Britt2020

iTrader: (7)

I believe I have the one you are referring to. I think Jason From Texas Drivetrain is the mechanic in that article. It's a good one.

SladeX

Adding the backbrace is something you can do, but have to be careful on keeping it true. Only tack welds hold the tubes to the center pumpkin.

Whenever you weld something, you will expose it to incredible heat which in the case of even the 9 inch, will yank on the tubes and distort it.

A safer way of securing the tubes would be to complete the weld all the way around the pumpkin. Some rear end covers exist which connect to the tubes as well and provide some bracing as well.

The torque arm question is the biggest issue. With the stress laid down in that area and the "pinion" flex that occurs, I don't think there is anyway you can reinforce that spot on the stock 10bolt. As stated, the 12 bolt also suffers from this when faced with the instant torque load of a 6 speed. The base design of a torque arm with the "classic" layout of the ring/pinion means you need some serious material to be used or some kind of bracing design to hold that force in check OR you go strange s60.

1981TA

iTrader: (7)

Re: the c-clip issue - you can mod a 10/12 bolt housing to take ford-style bolt-in axles. Moser makes kits. I put them on my 10 bolt (8.5"), with an eye toward using the setup in a Road race setting. I also have a truetrak diff in the car.

Here's a couple crazy ideas, following on the OPs desire to reduce weaknesses and movement of parts that aren't supposed to move. What do you think of the following, provided you have the time and expertise to do these (not having to pay for a largely labor intensive task:

1. Replace the stock pinion crush sleeve with a solid sleeve.
2. Mod an older 8.5/8.6" 10 bolt to bolt into a 4th gen (assuming we're dealing with a dedicated drag car-no ABS worries). The bigger 10 bolt diffs are still fairly common (Roadmaster, 90s Impala/Caprice, some light trucks, etc)

Britt2020

iTrader: (7)

I wonder what help polly bushings and a TA that only applied vertical force would be, if any. I do like the solid sleeve idea.
I'm just looking to work out something with this 10 bolt design, not replace it. This is more of a "lets see what we can do to improve this rear" type project.

ponchjoe

I believe you are correct on the HPP article author. If I find out I have something different I'll let you know.
I'm following this thread because I have had the same idea since reading about the issues with the 10 bolt. Although new to the LS Fbody I'm not new to the world of repair.
It is not beefy enough to be a track star but a real world street rearend would have potential.

Britt2020

iTrader: (7)

Definitely let me know. That's where I'm at with these 10 bolts also, I'm not expecting it to do anymore than what the R&P can hold. My thing is to get the rear to the point where the R&P fails because it is past its threshold, not because the tubes are warping under load, the TA is stressing the housing or the crush sleeve is allowing slack.

Cra-Z Larry

I had a solid pinion spacer put in my 10 bolt on the last rebuild, ended up breaking the spider gears in the Yukon posi and chipping a tooth off the ring gear. It was extremely noisy!! I switched to a 12 bolt after that.
The TA seems to be the problem so change the mounts to the new Moser Fab9 style or possibly the style BMR uses on their 1st gen TA conversion. Just some thoughts to ponder!! Good Luck!

DANOZ28

iTrader: (1)

i dont see the date but article from high perf pontiac "max effort fourth gen 10 bolt" by randall d allen, i printed 2007. the article says by using aftermarket axles, TA diff cover & welding axle tubes you can strengthen by 25%. other posters have mentioned replacing C clips (with what?) & solid pinion spacer? thats all i got. goodluck!

1981TA

iTrader: (7)

The c-clips would be replaced with:

1. c-clip eliminating axle bearings, of which there are two varieties, ball bearings (very common, but recommended for drag-only NO street) or roller bearing (didn't look into these much. I think Strange makes them); or

2. Modifying the axle housing ends to take bolt-in axles.

Both approaches may require brake backing plate mods. I went the second route, plus used a solid sleeve. The rear end is getting finished up today and I'll let people know my thoughts (noise, "feel", etc.)

01ssreda4

iTrader: (96)

Bunch of work for nothing IMO. Learn to work on them (free labor), parts are cheap. Put them together with fresh bearings and solid parts, and let her ride. Some people are thinkers, or over-thinkers, and you can drive yourself crazy over every little detail. It is just that though, thinking, in a real world application it is a waste of time. I've had great luck with the little 10 bolt, built a bunch for friends too. New bearings, good stock parts, good installer, they're better then most people give them credit for. Those people downing them, miss one of my 3 steps above!

Britt2020

iTrader: (7)

As much as I don't want to, I'm afraid I have to agree here. I have sat and stared at this thing for hours now and I'm in the same place as I was when I started thinking about doing it. At first I thought it would be worth the challenge, but the more I look at it I realize that at the end of the project I will have countless hours and a hand full of money into a unit with only a 7.6 inch ring gear. It seems that it would be more cost/time effective to just rebuild it when it breaks....Sorry to all that have contributed to the idea, but I'm afraid my enthusiasm for this has run dry.

SladeX

My rear survived to 180k before breaking the pinion gear. Regular fluid changes every 1.5 years. At 160k I sheared the spider gears moving to autocross, and 2 months ago 2 pinion gear teeth finally gave.

I put in my 3.90 gears at 50k. I added 130k, countless roll runs and 200+ drag launches since 2007, so I think I got my money's worth for the 10 bolt. Only ran drag radials and streets. Launches at 3k max.

Every 1.5 years I was changing out the damn pinion seal or refreshing the bearings/pinion/ring depth due to play. In the past 2 years I retired it from drag racing as I noted some play yet again in the last pinion seal change. Instead of going through with a refresh of the 10bolt I opted to save up for a 9 inch but was forced to get the 9 inch sooner due to the pinion giving up.

Yes you can keep "rebuilding" the rear, but what's your time worth to you to keep refreshing it like I did? If you do it yourself, you may save a bit, if you have a mechanic do it 2-3 times and you may find yourself halfway to the cost of an aftermarket rear.