Dragaholic

iTrader: (180)

I was told by an old timer that 12 bolts were weaker than 10 bolts! I was like...no way! 10 bolts are a common weak link in drivetrain and thats what 95% of them upgrade to. I dont know of any big dog running quick thats using a 10 bolt. So he replies with, "all you have to do is install strong axles and theyre fine!" He also says that, "its not the ring and pinion that breaks, its the axles that twist which result in other things breaking." Is any of this true or is he full of ! I dont have money at the moment for a 12 bolt and Im in the process of doing a conversion (M6 to 200-R4) and I hear that auto guys all day long run with 10 bolts making some quick passes. Is there anything that I could do to beef up my 10 bolt for now until I get money for a 12 bolt later? Thanks and any help is appreciated!

Colonel

The axles are rarely, and I do mean RARELY, the first thing to go. It's the ring/pinion, carrier, or spider gears that let loose. You'll be throwing money in the fire if you upgrade a 10 bolt's axles.

Stock rears work surprisingly well for A4s but not so well for M6s. It's possible to run 9s with a stock rear (though NOT advised!) I would advise going to a 12-bolt once you're pulling mid 1.5 60fts or so with an A4.

Don't worry with tossing money into 10-bolt upgrades. Just save your money for a 12-bolt rear if you really need the extra strength. It is FAR stronger than a 10-bolt.

Dragaholic

iTrader: (180)

So what would make him think that? The only thing that I could think of, is that back in the day, 10 bolts used an 8.5" ring gear as opposed to the 10 bolts now. (7.X) Is that correct? If so, then I think he still beleives that they are still made like that and if they were, then I would assume that they would be stronger with a few modifications. So what makes 10 bolts so weak? Besides 10 and 12, what makes 12 bolts stronger and hold up to more power? I want to get as much info as I can that way when I see this person, I can really know what Im talking about, and actually prove something to him and make him open up his eyes! I want to be able to correct him and inform him of correct information. So no matter how much money you dump into a 10 bolt, it will never compare to a 12 bolt? Thanks Colonel for your input, let me know what you think on these next questions. COLONEL

Freak

the 8.5 inch rears are very strong, I saw an all steel 55 chevy wagon running tens going wheels up on an 8.5...

as to what makes the 7.5/7.625 weak? everything. the ring gear limits the size of the pinion, and the diff, which limits the size of all the components in the diff. in addition the axles are smaller, and necked down (problaby to save weight) the bearings are smaller (probalby to decrease friction) and the case is smaller (again problaby for weight).

You have to remember that these things were designed for a late 70s econo car, right after the gas crisis, and weight/friction were becoming an issue becasue of growing concerns of gas mileage. also with the weak motors being put into cars tat that time there wasnt much concern of breaking them, I honestly dont think there was a single car they were put in through the at least mid 80's that could stand a chance of breaking one in anything remotely resembling stock trim.

I had a 78 malibu, with a pretty hardcore 327 and stall in it, and the 7.5 managed to live behind it, but I belive a lot of that was due to the fact that I had 2.29 gears, crappy tires, and the one wheel peel.

EDIT: I agree totaly with the Col. in that 12 bolts are stronger than the 8.5, 8.2 or 7.5 ten bolts.

4thGENRETARD

A lot of guys here always mod to 12 bolts Chevy. how about the FORD 9 inch? Is it less frequently used because it would be a Mutant swap? or there are other reasons.

Colonel

Freak nailed it. EVERYTHING is smaller and weaker in the 10-bolt and he's right, there is ALOT of difference between the 8.5" 10-bolts and the puny little 10-bolts that come in these cars. The guy you're talking about is probably familiar with the 8.5". Even then, the 12-bolt is still far stronger.

I had a Moser 9" rear in my '00 at one time. It was heavier, less efficient, raised the rear of the car up, and was noisier than my 12-bolt. I prefer the 12-bolt.

ford hater

Colonel knows!! May I add that the Moser(Ford,sic) 9" rear takes approx. 10% more horsepower to operate than does the 12 bolt.

Assassin

iTrader: (3)

your switching from an m6 to a 200r4, are you out of your mind?, arent they the weakest tranny's, i've got a 700r4 out of a 88 vette that got killed the 2nd pass down the track, the first gear is great but its a pos imo

Colonel

A stock 200R4 is a POS. But, a well built 200R4 can handle some insane power, not to mention that it's highly efficient.

Dragaholic

iTrader: (180)

Thats correct...the one that I will be running is rated to hold up to 800-900 rwhp and see 8 and 9 seconds passes all day. I know that one of the members on here MikeTexaSS is running one in his Impala (about a 4500 lb. car) and he makes low 11 passes not to mention on the bottle!

Benjamin Russick

iTrader: (1)

What about the Ford 8.8? How does it stack up against the 12 bolt in terms of efficiency, weight and cost? I have over 420rwhp N/A and a bunch more on the juice and I think the only reason my 10 bolt is still there is street tires.

Classic

iTrader: (3)

I'm currently running a Ford 9'' under my car - and yes it sucks that it is less efficent, but I don't think I'll ever break that thing. If you want to see the difference between a 10 bolt and a 9'' - just check out the size fo the ring gear

KRAZY K 2000 TA

iTrader: (5)

The pinion stem diameter is smaller on the later 10's on the older 10's there the same as the 12bolt i beleive but i broke an older 10 to spit all the ring gear bolts out cover two days after dirt track motor went in my 70 chevelle

KRAZY K 2000 TA

iTrader: (5)

By the way still have the chevelle 540 cubic inches later plus a nine inch and turbo 400 with trans brake