I have decided against getting an aluminum flywheel since the primary use of my car will be drag racing and street terrorizing, so that has freed up about $400 in the budget. I'm gonna be picking up some 4.10's, and i noticed something interesting while i was flipping through the catalog at my work. There is a complete bearing and seal rebuild kit that i can get for like 80 bucks. Will getting this kit actually extend the life of my poor rearend, or is it not worth my time???

Any info would be greatly appreciated,

trav

 

The bearing kit is pretty much a given requirement when swapping out gears. FYI

 

they only way to be nice to a 7-5/8 rear end is to not dump the clutch,launch on sticky tires @4000rpm.i still cant believe GM used this rear end EVER in a car that has power,they could have continued the 8.5 from 71-81 that sucker takes some abuse............

 

that really sucks that shattering my rear end is more or less inevitable. Oh well, i can get the 4.10's, gear kit and have them all installed pretty cheaply. So i am just gonna go as long as i can, and just not be surprised when it happens. By the way, i assumed the bearing and seal kit went hand in hand when a gear swap happens. I was planning on picking up the kit regardless of what people said, i was just wondering if it was actually gonna extend the life of my rear end.

thanks for the replies,
trav

 

IMO it's really a crapshoot with the rear ends. Provided you don't have extreme amounts of power you might get by for quite a while. But then I know a guy that's managed to break his rear end a couple times with only a couple bolt on's. On the other hand, I've got over 200 passes down the track on mine, over half of those on drag radials w/ an M6. Guess I got a "good" one. The only mod I've done to mine is put a girdle on it and keep a fresh change of fluid in it annually.

 

Take that $400, and put it in a side bank account where you can put money in, but can't pull the money until you've reached a certain amount. I did this with my bank (maybe its because i live in a small rural town) but once i get $2600 saved up im getting a Strange bolt-in 12 bolt 3.73 posi rearend...just an idea...might take awhile, but is well worth it.

Dave

 

the best advice I have heard yet. Not to mention, putting those 4:10's in your 7.5 is gonna make the rearend even weaker, because the thickness on the ring and pinion teeth is a lot thinner. I broke my 7.5 with just 4:10's and headers, and drag radials. Soon after, I got it rebuilt, put my stroker in the car, and BOOM again, on street tires this time. Keep in mind this never happened at the track, this was all street stuff. I learned that no matter how much money you put into a 7.5, in the end its still a 7.5. Dont waste your money, save it and put it towards a 12 bolt. Especially with an m6.

 

this is a crappy situation i'm in. The whole reason why i want a gear swap is when i'm at the end of the 1/4 i'm either slamming into the rev limiter in 3rd gear or just barely getting into 4th gear. Looks like i am more or less stuck running my high 12's until i save up for a 12-bolt.



trav

 

you could always run a taller tire...or bump up the rev limiter...

 

as far as costs go a few guys have installed the ford 8.8 from the stang,put gm mounting brackets on and fab-up a torque arm mount this can be done for 600.00 or less....................

 

autos really help out the life to the rear. not as much of a shock when you launch

 

http://www.thirdgen.org/newdesign/te...nguprear.shtml

 

bumping up the rev limiter isnt really an option, it's already set at 6800RPM. I can get the 4.10's and have them installed for about 300 bucks. I think i am going to have them installed, make about 10 runs, and once i get my 12.5 or better i will take it easy and save up for a 12-bolt. Luckily i work at checker auto parts and i work with a lot of commercial customers, so i can swing some deals..thats why i can get the gears and have them installed so cheap

I really appreciate all the replies!!

trav

 

THings to improve the life expectancy of the 10 bolt:

Crush sleeve eliminator (aka solid pinion spacer)
High quality (GM Motive or Strange) gearsets
Torsen differential
Girdle cover with the bearing preload caps.
Bearing cap stud kit

Question: Does Moser make beefed up axles for the 10 bolt? You never hear of it because anyone needing an upgrade buys a 12 bolt, but I have seen axles fail on a 10 bolt and with the above modifications beefed up axles would be the last remaining piece to the puzzle.

Even with all the above, with enough HP and the right clutch and sticky tires you are going to break it.

The question is is it worth $2500 for a 12 bolt or are you willing to spend $500 to put in a new diff and gearset everytime they break. That's 5 replacements for the same cost.

I'm swapping in a 6 speed this winter. My 10 bolt stock survived dozens of dead hook launches on ET streets, and with 3.73s, solid pinion spacer, cap studs, and girdle its survived about a dozen more. But I'm selling the ET streets and moving to drag radials because I am afraid to pop the 10 bolt and with a baby on the way I can't be dumping $2500 on a 12 bolt out of the blue.

So...I won't be launching at terribly high RPMs needless to say. Street Twin plus 360rwhp plus stickies = short life for the 10 bolt.

 

i'm in the same boat you are. I'm gonna be running a spec stage 3, 4.10's and nitto drags. I just hope to get 10-20 runs out of her without breaking, so i can say that i ran 12.5 or better. Once i get my 12.5 or better, i plan on taking it easy on her for the rest of the summer and save up for a 12-bolt. it really sucks to have such a weak link in our cars, but meh, what can you do.


trav