JEB99TA

iTrader: (32)

I've installed a HD Eaton posi unit and factory 3.73's. How much stronger is my rearend over the old 3.23's and Zexel-Torson posi? In other words, how much power do you think the heavy duty Eaton will hold over the stocker?

mzoomora

iTrader: (36)

The diff case is stronger now, but the ring and pinion are the new weakest link.

Edit- NM I just re-read the post. The 3.73's are going to be weaker than the 3.23's and putmore stress on the rest of the diff. They multiply more torque and the pinion is smaller.

JEB99TA

iTrader: (32)

My car is an A4 and I'm on street tires, so, I think I'll be OK ... just considering going back to Nitto's on a VHT treated track, but, I think something will break if I push it with about a 8 second burnout on Nitto's. Relo brackets will add to the stress ... with the pinion angle being steeper. Think I ought to push it?

... just can't afford a 12-bolt after dropping $13,500 on this new motor and a another $3,500 on a FLP racebuilt tranny.

99PontTA

the eaton is much much stronger than the torsen....youll never break it....it doesn't have the small gearing thats so easy break in the torsen.The weak point now like was said is the R&P....and the axles.INSTALL A STUD GIRDLE if you really want to add strength to the rear!That should be everyones 1st mod!

DONAIMIAN

iTrader: (18)

That depends on what torsen. The torsen T2R is the strongest diff you can put in a 10 bolt.

99PontTA

lol i seriously doubt he pulled a T2R out and replaced it with a eaton

JEB99TA

iTrader: (32)

No, I took the old stocker out and replaced it with the HD Eaton. Ironically, a MAC supporting girdle cover WAS my first mod ... ... saving for a 12-bolt now but I wnat to make the 10-bolt last until I can afford the 12-bolt. I guess if I just keep street tires on it I will prob be OK.

racer88

It's the luck of the draw with broken rear ends. You are putting down more power than I was on Nitto's when I had my 10 bolt. But A4's don't get the shock that the M6's do launching. If you are on Nitto's you should be fine. They hook and they spin depending on the track. I mean they spin as they hook if the track is so so. I ran 4.10's in my 10 bolt and did burnouts all the time to alot of hard 2nd gear hits on the street and I got over 60 passes with that rear with 4.10's even cut a 1.74 60' on it.

I have friends out on MT ET streets with 10 bolts and A4's and they are just fine. I would tho get a T/A Girdle if you can for added support.

JEB99TA

iTrader: (32)

Hey again! ... already have a MAC rear girdle cover that's actually a little stronger/thicker than the T/A girdle cover. I see a lot of people here spraying 150-200 shot hole shots with a 10-bolt (A4's mostly). I see people consistently running high 10's on the 10-bolt, as well. These are generally the 'exception' and not the 'rule'. It doesn't seem so much like a crap shoot. It seems more like either the rearend was set up professionally or it wasn't.

A lot of good answers here. My motor is in now and will be tuned and tested next week. With street tires, I don't think I'll hook good enough to break the rearend or spin an axle. Even though I did finally have them weld in subframes and relo brackets. I guess I'll go ahead and do a little 150 dryshot so I don't get beat up by the new Z06 C6's. As long as I don't spray through the gears, I should be OK I guess. What are your thoughts? My new AFR cam has a degree of advance ground in, so, the PCM should pull the other other 4-5 degrees. Think the rearend will handle this on street tires? Remember, the 3.73's are the harder factory gears and I have replaced the stock Zexell-Torsen with a HD Eaton posi unit.

JEB99TA

iTrader: (32)

Oh yeah, this is totally irrelevant, but, my tranny is toast, so, there goes my rearend money. Oh well, I guess someone decided I needed a new FLP level 5 ... LOL! It'll be in this week ... will have to depend on the HD Eaton posi for now.

racer88

That's cool! My Man just got his car back together 4L80 with a Yank 3600 stall and everything is working. We'll see how the car does Weds night on street tires

Mine on the other hand is fine but Heads are out for the time being this is if the dog's ultrasound isn't good Thurs and he needs surgery to remove a stone. If it's good then I will see if there is enough $$ leftover to order the heads after buying the shaft and 15" DR's for the street.

Other than that, my driveshaft is going on and I will be launching it hard in the likes to see some mid 1.6 shorts.

chicane

Thats funny....... I think everyone should put a real differential in the chassis before they stuff a bunch of HP and TQ into it and start blowing everything else up because of it. Besides, a girdle is a bandaid that doesnt really work. Installing a steel main cap with larger studs on just the drivers side cap alone, is ten times better than a girdle.

That doesnt fly either. Anytime you try and stuff 10 pounds of **** into a 5 pound bag.... it makes it weaker. The less moving parts the better and dont get me wrong....... I love Torsen differentials. I have used them for years, but in a flimsy 7.5 10 bolt.. !?!! uh, no.

AN Eaton, hands down is the strongest differential you can put into a 7.5".

99PontTA

a girdle works just fine and you can do it in the driveway...how many newbies are gonna change a bearing cap and studs?????

chicane

So tell me how it works just fine ??

And a good newbie will pay someone that knows what they are doing to do just that.

DesertFox

iTrader: (2)

Whats the difference? Im a newbie.

Josh

99PontTA

the stud girdle reinforces the entire case and main caps by supporting the center of the carrier bearing caps and holding the case from deforming under heavy loads.Its a heavy cover plate replaces the stock cover.The stock cover does nothing but hold the oil in....the girdle holds the case in tension preloading it from sudden shock loads.Its like flexing your stomach muscles before someone punches you.

Replacing the carrier cap and bolts does nothing to reinforce the case deforming under heavy loads but does reinforce the carrier bearing cap from pulling and stretching ...actually both things would be good to do EXCEPT....other parts in the rear will break if you push it too hard......but those mods will make a stock 10 bolt behave with a stock engine for a long time.

Hawkcmc

iTrader: (1)

Everyone's first mod should be a 9 inch.

CMC

chicane

First off, you are dealing with multiple dissimilar metals..... all of which grow at difference rates. If the entire unit was constructed of the same material, I might actual believe that one could control the actual pre load applied to the caps them selves. The girdle does nothing for the case itself..... its aluminum and only used in circumference which is not where you need any help.

Secondly, its the caps that fails. If you replace the cap with a quality ferrous material and use fastners that clamp the laod.... you will increase the strength of the peticular component by a much greater amount than some uncontrolled and growing...... bolt on cover.

Lastly. Its a flippin 7.5". You could throw all the money in the world at it and its still gonna brake. Period.

The designer/engineer of this product is a friend of the differential business I once operated. He built it as an idea to make some money. Well guess what ? He sold the rights to it.... and did. Simple metalurgical principals proove that this product can do just as much to hurt the differential as it can do to help it. It really comes down to how its set up....... and that is a trial and error concept that most, if not all of the individuals who purchase it..... will attempt to do.

Its a great bandaid to the known fact that if you add hp/tq.... the 7.5" differential will fail. Its never been a question of 'if'.... but 'when'.

DJ's Z

iTrader: (10)

So...is purchasing a TA cover and stud girdle really just to help prolong the life of the ring gear and pinion rather than truly strengthen the rear end housing?

What about with a 12 bolt? Does it also need better quality material in the caps and is a TA cover/stud girdle just a waste of $$$ ?

DesertFox

iTrader: (2)

Thats some good readin'.
Thanks,
Josh