88IROC350TPI

This is driving me completely nuts. I have a Dana 44 that is setup to use 89-92 disc brakes but I can't find these brakes anywhere.

At first (some may remember) I tried adapting my '88 9-bolt discs to this rear but thats failed. It *could* be done but it'll involve lots of welding/cutting work (not worth the effort). The backing plate bolt holes do NOT line up (like I had previously thought - and even measured ...but they are just slightly off).

Nobody has a complete 89-92 disc brake setup. All I can seem to find is little bits and peices.

Is there any other solution to this? Is it just that the 9-bolt has a different axle bolt pattern than 10-bolt/Dana44 or is it that the Dana 44 has a different pattern and uses a special backing plate?

Here is a picture I took of the backing plates. I *need* brakes for this car. Is it possible that I could use pre-89 10-bolt discs or do you think I'll be in the same boat?

PLEASE throw me some suggestions here. I hate having this car sitting on jackstands only because I don't have rear brakes.

88IROC350TPI

Sorry for all you dial-up people (me included) but here they are installed on the rears

This is the dana 44

88IROC350TPI

Here is my 9-bolt

RB83L69

The old garbage cast-iron brakes are the same on both 9- and 10-bolt cars. IMHO you'd have to have a head full of rocks to go to extra effort to downgrade a PBR-equipped rear to that dysfunctional crap. Don't go there.

You need to get a whole rear from somwhere. Watch the boneyards for a 90-92 car to come in, and snarf the rear the minute you see it. Nobody in his right mind is going to sell those brakes apart from the rear, unless the rear is majorly trashed somehow. It may require some patience.

OBTW, when you find the rear, you can sell the axles for a pretty penny.... everybody's trying to find those too, and they all have the same problem as you.

If I was you I'd put the 9-bolt back in until I found the other rear end.

88IROC350TPI

The 9-bolt is finally broke. I drove around with it making noises for a year and 2 weeks after I bought the Dana 44 it started making a very very loud sheering sound (my car is cursed...)

Is it possible to use 4th gen disc brakes? I see them for sale all the time and remember reading it was possible on here. My only concern is that the Dana 44's bolt pattern is different than regular 10-bolt's so NO backing plates would fit?

88IROC350TPI

I found someone selling 89-92 calipers and rotors but they said they don't have the caliper cradles/carriers. Will they be hard to find or can I get them from GM or something? Did they also change the brake lines in 89?

Sorry for all the questions but this is all pretty confusing.

Thanks,
Chris

Jon92TA

Check this out in the tech article section:

https://www.thirdgen.org/newdesign/t...reardisc.shtml

88IROC350TPI

Can somebody with a 10-bolt disc rear measure the backing plate bolt holes for me? I'm never going to find 89-92 brakes so I need some way of adapting older style ones. The 9-bolt's axle bolts are spaced farther apart than the Dana 44's. I'm hoping the 10-bolt will be the same as the Dana.

I'm getting really despirate here....

thanks,
chris

ebmiller88

iTrader: (7)

Just contact AndyZ28! He can get you the whole kit, ready to go with brake lines and all.

Ed

Fastcamaro87

88iroc350tpi

what measurements do you need? i can go measure mine because it is still all apart from my adjustable proportioning valve and line lock install, let me know if u need me to measure it for you

Matt

88IROC350TPI

On your rear there should be 4 bolts on the end of each axle (behind the caliper mounting plate). I need to know the distance between all of them (from like the middle of the bolt itself). Don't just measure 2, measure all 4 because they aren't perfectly square shaped.

If you can do this it would be greatly appreciated!

Thanks,
Chris

ebmiller88

iTrader: (7)

Look here, second post.

https://www.thirdgen.org/techbb2/sho...=backing+plate

HTH...Ed

PS: It's a good thread to read for more info on the backing plate issue.

88IROC350TPI

Thanks ebmiller88 that helps confirm weither the bolt pattern is the same on my Dana 44 as a regular 10-bolt. I'm going to go measure it right now.

My new plan is to use pre-89 10-bolt discs now (until the same I can find some better brakes). I am assuming (hoping) that pre-89 10-bolts have the same axle bolt pattern as 89-up?


...........going off to the "shop" to measure now.

e-man

Just drill new holes in the in the backing plate.I did this to use my PBR that were on the stock 9-bolt when I switched to a 10 bolt.I made a tempate out of card board and just drilled new holes not a single problemand took 20 min.

88IROC350TPI

I was thinking of doing that except it seems the flange (the thing you can't get off without removing the bearing) wont sit against the 9-bolt backing plate properly...

ebmiller88

iTrader: (7)

Contact AndyZ28. He has backing plates for sale that fit both 9 and 10 bolt rears and maybe Danas. I've never seen one so I don't know.

Ed

BretD 88GTA

I wouldn't go thru the effort of installing the '88 9-bolt brakes. The cast iron calipers are not as good as the 89-92 PBR calipers. Not to mention that the '88 and earlier cars have the rear calipers set up in an "opposing" postion. The driver's side caliper sits on the trailing edge of the rotor while the passenger side sits on the leading edge.

Every rear disc brake car produced from 89-92 received the PBR rear calipers. They must be available somewhere. Lots of people have converted their pre '89 cars over to the PBR rear set-up so it is doable. The calipers should be easy to come by. It's the carriers that could be tricky. One of the guys in my car club installed a Dana 44 rearend on his '92 IROC. I'd contact him (he goes by JERRYWHO) on this site or AndyZ28 and/or do a little more searching.

Another option would to be to buy the Baer rear disc brake kit. It will have everything you need but it will run around $700+. Provided the Baer brackets fit the Dana rearend.

88IROC350TPI

I was doing some more thinking/inspecting today and I *could* use my 9-bolt brakes. I'm going to have my friend weld up the backing plate holes and then re-drill them for the Dana 44's pattern. Then I'm just going to shim the axle flange so it sits properly against the axle

Yeah, I know pre-89 style brakes are "crap" but when you are poor they sure do work fine......

wuter

You can grab the calipers off a 93-97 4th gen. they are pbr's and will bolt right up, this is what i have on my car now.

Z28ricer

iTrader: (2)

If you have the brake mounting plate in those pics, which im guessing you do unless you pulled it off the net, that looks like a pbr caliper plate which is the hard part, you can easily get the calipers and mounting cradles along with rotors and ebrake cables, email me, i might have most of it or at least be able to help u find it.

89firechicken

i'm not sure of the dana but i have a 8.5 rear for my el camino and i pulled the brakes off a old caddy i haven't fitted them yet but a little fab work never hurt those caddy brakes are 11" rotors with a 5x5 bolt pattern. if you were to use that setup you would have to get aftermarket rotors withthe third gen bolt pattern.

ebmiller88

iTrader: (7)

(deleted)

Ed

88IROC350TPI

I'm going to drill new holes and have my friend make a shim for the gap today ...i'll keep yas updated. Here are some pictures of the problems

88IROC350TPI

Here is how far the bolts are misaligned ...its not that bad at all. The biggest problem should be the shim ...the 9-bolt backing plate is much thinner than the one off the Dana 44 thus leaving a gap.

RB83L69

Whatever you do, DON"T SODOMIZE THE REAR END TO DOWNGRADE THE BRAKES!!!!!!!!! At least if you're going to rig your brakes so you can put the garbage ones on your primo rear end, do it in such a way that you don't destroy the rear end, and can put the right thing on it some day. Do any necessary ...... ummmm, alternative engineering to the backing plate, NOT the rear end.

You've got a $1000 worth rear end there. There are lots of people that would love to find one of those and would pay good money for it. If you aren't willing to do what it takes to install it right, then please sell it to someone who is; don't hack it and turn it into trash by cobbling inferior brakes onto it in such a way that the rear is damaged or destroyed by being altered in any way.

88IROC350TPI

You are right. I am not going to hack away at the rear in any way. Just my 9-bolt backing plates. I'll be keeping an eye out for a good priced PBR brake setup for now on but for now I just need to get this thing moving. I could not lay a finger on the rear itself because I do realize its worth a lot of money.

Z28ricer

iTrader: (2)

I'd give 1k for that axle in a heartbeat, anyway if you have the brackets in the first pics, they're for the pbr brakes, get yourself a set of used 3rd or 4th gen calipers 89-97 , the 92 parking cables, a set of rotors, and the caliper carriers, i know i have a set of carriers i'd sell u cheap, maybe the calipers, but no rotors or parking brake cables, you're wasting time trying to put the crappy irons on there.

Justins86bird

Have you looked into using the rear brakes of an LS1? Don't know if the backing plate bolt pattern is the same as what it is on the Dana44, but it might be worth checking out.