One wheel perl on a 342 posi

[WILLIAM FLYNN]

My 81 Z28 has had a upgrade, I put a 383 stroker replaced the 5.0,109K 305 .
All new drive line except a recently rebuilt rear.

The rear differential was rebuilt in 2014.
Stock 342 posi.

Now the HP has tripled and Tq is 460 on engine dyno.
I occasionally get the passenger side only spinning, I've witnessed this from the rear view mirror leaving a distinctive black stripe.

Any thoughts if I can save this rear ,maybe a build change or rebuild.

I'm definitely going currie or Quick performance, likely the mini tub and possibly 4 link.
It's a costly project.

Feeling like rebounding/ recouping first from my 20K investment in 383 ,tremic TKX 5.
Frame connector, all the new parts that go along with the rebuild.
Radiator, electric fans ,serpentine belt system.
AC,pro flo 4.

 

[Gary S]

Check the preload on the posi clutches. If the clutches are worn, they get loose and slip. There are good threads posted here in the past that tell you how to check it out at home yourself.

 

[earnhardtgm3]

Replace the posi unit with a good aftermarket one and upgrade to 30 spline axles..

 

[73Z L92]

Kind of depends on long term goals.
If you are serious about the 9" and four link I wouldn't spend a nickel on you current rear end.
But I've had really good luck with Detroit Trutrac and as said above 30 spline axles in 10 bolt Camaro rear ends. I also have the axle welded to the center section by local pro welder.
Seems that both Currie and Quick get very good reviews.

 

[muscl car]

I've got a Quick Performance Ford 9"axle in my Camaro and it has alot of high quality parts in it
. The housing has been braced and has an oil drain on the bottom of the housing . The axle tubes are billet steel and has big bearing ends and also has billet spring perches


The center chunk has a billet aluminum pinion support and has aluminum carrier assy .


The pinion yoke is billet aluminum for 1350 u joints and I have billet aluminum 35 spline carrier with a billet full spool . The axles are high strength billet steel 35 spline axles with 1/2 inch wheel studs . I'm running disc brakes also available from Quick Performance

I also had another center chunk made with the same components but the ring and pinion is mfgd with a softer billet steel so it can absorb the shock load of 3500rpm transbrake launches . The ring and pinion gears are 3.89 ratio



This axle is rated for 1500 plus hp and I only had to pay $4200.00

 

[muscl car]

Found some pictures of the Quick Performance Ford 9"axle prior to installing it in my Camaro . The center chunk with the Anodized blue pinion support is soft ring and pinion for drag racing launching off the Transbrake

 

[2ndGenCrazy]

The 8.5 is fine for your current engine. I raced my 73 with stock axles and went 11.60's @ 116 around 1990 or so. I would upgrade to Moser street axles if doing that today. 1.63 60' with an ATI 8" converter. I would say that the manual transmission changes the equation though. A Ford 9 is the ultimate if your going to upgrade. You will likely move the failure mode to the transmission/clutch.

 

[hd_cat]

My 81 Z28 has had a upgrade, I put a 383 stroker replaced the 5.0,109K 305 .
All new drive line except a recently rebuilt rear.

The rear differential was rebuilt in 2014.
Stock 342 posi.

Now the HP has tripled and Tq is 460 on engine dyno.
I occasionally get the passenger side only spinning, I've witnessed this from the rear view mirror leaving a distinctive black stripe.

Any thoughts if I can save this rear ,maybe a build change or rebuild.

I'm definitely going currie or Quick performance, likely the mini tub and possibly 4 link.
It's a costly project.

Feeling like rebounding/ recouping first from my 20K investment in 383 ,tremic TKX 5.
Frame connector, all the new parts that go along with the rebuild.
Radiator, electric fans ,serpentine belt system.
AC,pro flo 4.

The least expensive route would be to rebuild the posi, which can be done without the need to redo the gear set-up, new clutches and springs AND new posi additive. The next level would be to use an aftermarket posi with whichever gearset you choose, and aftermarket axles which should be available with a greater number of splines than the stock 28-spline units. The '73 has a Strange Crate 12-bolt unit with 3.73:1 ratio and 33-spline axles, cost was $2700 a few years back...

 

[WILLIAM FLYNN]

Fantastic advise guy,affordable route for now is to change clutches,do additive with fuild .

 

[besserspat]

Yep start with what you have, improve it before slapping a bunch of parts ( that are now getting increasinglly made of chinesium) together in hopes to go faster/stronger.

Lots of guys here running low 10s high 9s on 8.5 10 bolts. Simply with welded tubes a new carrier and 30 splines axles... but for the street and if you are using any sort of street tires , those will be the fuse for your driveline and the tires will lose traction before you snap something...

Landy's or Grumpy's style wannabes with manual transmissions are usually the ones that can explode pretty much any drivelines even on the street...

Peter