need ur help please.i have 88 gta with a 9 bolt well i blew it up.my buddy has 89 gta with a 9 bolt.now i now that it will bolt right in.but my question is there any differences any the brake setups or anything i should now before i start this.thank for ur time

 

Disc to disc or drum to drum? Your 88, if it's a disc brake rear, should have 10.5" rotors and single-piston Delco-Moraine iron calipers. How about the 89? 11.7" rotors and single-piston alum calipers? If so, you'll need its proportioning valve.

JamesC

 

both rears r disc.but his still useing the calipers.so can i just use my set thats on my rear

 

1989 9-bolt rear brakes are a vast improvement over your present set-up. I would go with the 89 11.655 rotors and PBR aluminum calipers.

 

If I understand everything correctly, yes, but you'll have to swap your backing plates and hard lines onto the 89 rear.

JamesC

 

thanks for the help .r those backing plates prest on or bolted on. its been awhile since i have been to the garage...

 

Bolted.

JamesC

 

Don't you have to press the bearings off of the axles to get the caliper brackets off?

 

Nope,caliper bracket swap an easy job-fixing the axle
seals though does require pulling the axle bearings.
The bracket for '88-earlier has round dust sheild
attached while '89 up PBR does not-so that is a way
to tell them apart if calipers are missing.

 

Yeah, about the only special tool you'll need is one of the slide-hammer type axle pullers that you can rent from most parts stores. Once you undo the four bolts from the backing plate, just attach the axle puller to your wheel studs and yank the axles out. Then you'll be able to remove the backing plates. Man, if I were you, I'd really make an effort to talk your buddy out of the 89 brake setup. As stated above, the PBR aluminum calipers and larger rotors are leagues better than the 88-older style discs. The standard, drum brake style master cylinder is what you'd need for the 89-up rear discs. The 88-older, 4-wheel disc cars use a unique master cylinder that has a different fluid volume compared to the 89-up disc cars and all drum cars. So you'd have to get the drum style m/c and of course an 89, 4-wheel disc proportioning valve. That is, if you can actually talk him out of those brakes. Btw, if you had trouble getting your hands on an 89 disc PV, the standard drum one works ok with the PBR discs too.

 

If you use your brakes and remove the PBR brackets I might be able to use them. I have an '88 9 bolt for sale and it seems that I might be able to sell it easier if it had the later brackets on it.