I have a 9 bolt posi 3.45 rear end in my 87 GTA. I want to know who hard it is to switch to a 10 bolt. Will i lose the disc brakes in the rear? How do i get posi again since the 10 bolt isn't? PLEASE HELP

 

Also i was wondering if i keep the 9 bolt, i called DTS about the 3.70 gears, they are $312 but they told me i need to pull the pumpkin cover off to see what bearings i need. What are they talking about? And last, when i drive the rear end sounds like i'm dragging something but i'm not, i was told it's the gear pinion? GM discontinued it, so if i keep the 9 bolt and buy the 3.70, will that fix the noise?

 

I did this in my 88 GTA, it took about a good 6-8 hours with two people, but it wasn't that hard. I would recommend using power tools though. I couldn't find parts for the 9 bolt excpet gears, so I scrapped it for a 10 bolt. They install just the same as you take them out. Once you un bolt the shocks from the rear end it will drop out. Then it is a matter of uninstalling the driveshaft, torque arm from the rear end, rear trailing arms, sway bar, panhard bar. With the breaks, just disconnect them from the rotors. The breakline that runs across the rear end is held in by a couple of 10mm bolts, and just some clips that need to be bent out. Then it should come right out. Let me know if you need any other advice.

 

Thanks for the advice, so basically it's not hard but time consuming, i can keep the rear disc brakes? Do you still have posi traction?

 

When you purchase your rear end, make sure it is a posi traction, disc brake rear end.

 

The disk brakes won't work on the drum axle. The backing plate mounting is different between drums and disks. To convert the drums to disk you'll need to modify how the disk brake caliper mount attaches to the drum axle. You're better off either finding a disk brake 10 bolt or converting over to drum brakes. If you find a disk brake 10 bolt the all you need to do is bolt it in and swap over the calipers, lines etc.

------------------
Stephen's racing page

87 IROC-Z Pro ET Bracket Race Car and knocking on the SuperPro ET class
383 stroker (carbed) with double hump cast iron heads and pump gas
LS6 Big Block buildup now in progress

Best results before the engine blew up
Best ET on a time slip: 11.857
Best corrected ET: 11.163
Best MPH on a time slip: 117.87
Best corrected MPH: 126.10
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!

Member of the Calgary Drag Racing Association

 

ok, with help from everyone so far, i've found a place besides DTS that has gears for the 9 bolt. Reider racing. The gears are $12 cheaper and the bearings are alot cheaper. So i have access to the parts i need. I was quoted $175 to have someone put the gears in and new bearings, since i can't do it myself. Oh also the gears from reider are 3:73, DTS has 3:70, i know not really a difference but i thought i'd just ad that in. So now i have to decide if i want to keep the 9 bolt or still go with the 10 bolt and put 4:10 in. Anymore advice?