7.5 Rear

[lt1 kenobi]

Can they be built up to hold at all?? I really don't have the cash to spring for a GN rear end right now... I'll be around the 400/400 mark.. The car will see the track occasionally on drag radials... NOT SLICKS. What can I do to build up the rear?

 

[megaladon6]

the weak point is the ring and pinion. the axles are next.

 

[85 Cutlass Brougham]

It all depends on how much power you are really making. The drag radials could be enough to kill it. This is not a strong axle in any way and will not take too much stress. What you have is a tug of war between the weight of the car and it's inherent inertia and the power of the engine that is trying to overcome it. The axle, etc is the rope between the opposing sides and if it is thin enough, it will snap. In my opinion, it is not worth the money to beef it up. By the time you get a good diff, axles, etc in it, you could have bought a 8.5. By the time you buy and build up an 8.5 with all of that stuff, you could have had a 9 inch. However, a stock 8.5 with a decent diff in it should be more than up to the task in stock form, provided you don't throw nitrous at it in any large amount.

 

[KrisW]

the weak point is the ring and pinion. the axles are next.

I always break the axle shafts first!

They can take 400 hp if you run good 28 spline axle shafts (like Moser) and a 4th gen f-body Zexel torsen posi unit. Beyond 400 hp it's a crap shoot.

As stated above, for the money spent on axle shafts and a used posi, you'll be around 600 bucks + and then you could've started on an aftermarket setup like the ford 9" or 8.8"

I'm not rebuilding any more 7.5s.

 

[megaladon6]

I always break the axle shafts first!

I'm not rebuilding any more 7.5s.

if you're breakin' the axles, why do you need to rebuild it?

 

[beeterolds]

my Cutlass ran 13.30s with street tires..it was reliable..as long as you dont beat the crap out of it..

 

[KrisW]

I always break the axle shafts first!

I'm not rebuilding any more 7.5s.

if you're breakin' the axles, why do you need to rebuild it?

I mean in the context of repairing them in any fashion. The last one I had the pinion nut was coming loose and leaking oil. Tightening the nut is the most I'm willing to do to them now.

If you are upgrading to stronger axles and swapping the diff carrier to a posi, you should replace the bearings, right? That's what rebuild means to me.

 

[megaladon6]

gotcha.
i agree with your def, of a rebuild.

 

[beeterolds]

ive seen guys go deep into the 11s with the 7.5/7.625 the pinion always goes first...as long as u use gears from a good aftermarket manufacturer like Richmond that heat treats them youll have no problems...as long as you dont do brake stands or run slicks all the time..

 

[1980Gbody]

summit has a set of forged axles for around 200 for the 7.5 inch g body rearends

i was thinking about those axles richmond ing and pinion gears and a posi system because i also cant afford a 8.5 or a 9 inch right now
how well would that hold up