DANOZ28

iTrader: (1)

hello, i cant decide if i'm going to part with big money for a 12 bolt next year or beef up my 10 bolt. i have an auto and will hardly ever see the track. a new 12 bolt plus alum cover plus shipping is $2500. plus labor i'm looking at close to 3k. i'm not made of doe!. thx dan

bearcatt

iTrader: (41)

Here's a article about a " built " 10 bolt.

http://www.highperformancepontiac.co...earend_rebuild

Also here's a thread from a member here, regarding a " built " 10 bolt.

https://ls1tech.com/forums/gears-axles/780254-strengthening-stock-10-bolt.html

Razor_Blade

iTrader: (8)

Like many people, I don't believe that a 7.5 is worth trying to strengthen up. The parts inside are just too puny. If you beat on it, it will eventually break. You can take it easy and they can last for a lot of street miles. So far mine has held up to 1.8 60' times in a stalled auto with M/T Drag Radials. It will break at some point.

The two things you need most to run the 7.5 are a spare in the garage and a friend with a trailer. I have both.

6spdpewterZ

oh yeah...i remember my first 10-bolt....bounced of the Rev limiter at 6k...whomp!! clack, clack, clack, clack!!!!!! oh good times!

bad2000z

iTrader: (4)

If it's hardly ever gonna see the track, don't waste your money on a 12 bolt. My car still has a 10 bolt, and I race it pretty often. It's not likely you'll break it on the street, especially with an A4. The only reason I don't have a 12 bolt is I can't afford one, so I run a "built" 10 bolt instead. It has welded axle tubes with an Eaton Posi, stock axles, and T/A Girdle.

monsterbreather

iTrader: (1)

with a 273 a4 like in your sig,id leave your 7.5 in there until, if , it gives you a problem.its lite weight!!! man, i couldnt tell you how easy it is to squash the crush collar with a half inch breaker bar..... but anyway, im in the 11s with a used set of 342s and the 273s i took out were perfect.alls good

v8juice

iTrader: (9)

built 10 bolts=A rear end that lasts about 5 minutes longer than the original untouched factory rear end.

chicane

"A waste of money" comes to mind... but I like v8juices' definition the best.

Remember... its not a question of 'if' it will... its a question of 'when' its going to fail. Modifications or not... you run a higher risk of something going wrong no matter if its "built" or not.

But for Gods sake man... dont purchase a pre-assembled unit from Moser or Strange. Call up someone like Scott at Drive Line and have him assemble the unit from the same parts. Life will be much better that way...

Horsepwraddict

iTrader: (12)

good brand gears (pro gears are less likely to break but aren't good for street use)
good axles
welded tubes
girdle cover

BlackScreaminMachine

iTrader: (17)

there is no such thing....

bad2000z

iTrader: (4)

Notice everyone who bitches about how much the 10 bolt sucks has an M6 car. An A4 car that almost never sees a drag strip will RARELY have a problem with the 10 bolt.

BlackScreaminMachine

iTrader: (17)

My 10 bolt in my A4 LT1 car lasted 3 seasons rnning 1.70 60 foots. But bottom line, they dont last.

bigsticksupra

iTrader: (3)

the axle in my 10 bolt lasted 2 passes and broke on the third with bfg drag radials.

8a8mfh

iTrader: (3)

Thats the risk you take. You say it's going to be close to $3000 for a 12 bolt. Ok say you 'beef up' your 7.5 for close to $1000 and it breaks. THEN you get a 12 bolt...you have almost $4000 in a rear thats more likely to hold up.

djsanchez2

iTrader: (14)

I was on my 3rd rearend when i got rid of my A4. No stall on DR's. Had 2.73's in the first 2. Then went 3.42's w/ a girdle cover and lasted a year, til i got my M6.
I averaged 1 year per 10 bolt behind an A4.
When i see problems with my M6 rear i'll just pop for a 12 bolt w/ 3.73's.

bad2000z

iTrader: (4)

READ THE ORIGINAL POST PEOPLE!! Why would he spend $2500+labor on a 12 bolt if he hardly ever goes to the track? How many of you A4 guys have broken your 10 bolt ON THE STREET, ON STREET TIRES? I'll admit, after 3 years of low 1.5 60' times I stripped an axle, but if I hadn't raced the car constantly it wouldn't have broke.

brad8266

iTrader: (23)

Read the damn thread title people. "Define built 10 bolt" Thats all the OP asked for. If you cant tell him what a built 10 bolt consists of and all you want to tell him is how much a 10 bolt sucks then because you arent helping at all.

hazard2k

iTrader: (10)

I personally have broken more posi units than i have gear sets. I keep replacing them with stockers though, so that’s probably most of the problem. After doing my build up http://geocities.com/duragizer444/install.html I have not experienced any problems with anything breaking. I have an M6 car that is full bolt on with a cam. I am by no means easy on the car either. Not necessarily going to the track, but I am always slamming through the gears as much as possible.

I would start with a good posi unit, either the eaton or auburn. Defentily use a girdle / stud kit. Upgrade the axles if you think you are going to get good enough traction to break one of them. Personally I opted to save my money and re-use the stockers. If putting in new gears, I would also use a solid pinion spacer to avoid having problems with a crush sleeve.

Good luck with the build
-Jeff

8a8mfh

iTrader: (3)

The first reply provides a link to as much information as he needs. In fact theres a comment in the link to another post here that says we see this question every other week.

The rest of the posts here are just motivation to get him to swap to a rear he'll never have to worry about, he asked the question, he's obviously concerned about it breaking.

All it takes is one trip to the track on street tires, street tires can = bad wheel hop. Wheel hop can kill a rear just as quick as power.

I'm sure there are plenty of people who have screwed around and wasted close to $3000 on broken 7.5's.
My theory is take that chance and someday you may have $6000 invested in rear end work before you have something thats strong enough to last, that last $3000 being a 12 bolt swap. Factor in towing charges from the track to your house too. Thats $300 for me.

BlackScreaminMachine

iTrader: (17)

Just a FYI i am one of the few that suffered wheel hop at the track with a 12 bolt w/ tru trac diff and broke that, Wheel hop can break anything. Mods in sig, I maybe make 330 rwhp.