Problems with Jeep DIsc conversion??

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superdart

Shade Tree Tinker Gnome.....
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Has anyone at all had problems installing the 95-99 Jeep GC rear disc brakes on their A-bodies?

I was getting ready to order axles for my 29 spline upgrade from Doctor Diff, and he indicated that he has heard lots of people having issues with the conversion. I want to make sure I am not going to have issues before I order these axles. The plan was to order them with the smaller Jeep centering register to eliminate the need to grind out the rotors.

Anyone?
 
Subscribing to this thread. I've heard its nearly a direct bolt on for the 8.25 rear. 8.75 might be different ?
 
8.75 is very different. I am working to convert my 8.25 over and will take notes and pictures as I go to settle this once and for all.
 
Superdart,
I had issues.

I went out and bought all of the hardware specified, even the caliper mounting brackets were from the same year (1995) as the brake parts I picked up. However, grind as I might, I couldn't get a single damn wheel I own fit on the hub.
The problem I had is that the caliper mounting bracket had those ears (which the brake pads slide on) and they interfered with the wheel fitting on the hub of the axle. When I tried to spin the tire, I could hear and feel the wheel hitting those caliper mounting bracket ears. I even put the c-clips and pin back in the center section (to push the axle out as much as possible), but it didn't help. I'm sure I was only off by a little bit, but even if I got it to clear, those tolerances would be mighty tight.
If somebody else has run into this issue, please speak up. I tried both 15" rallye wheels and 15" and 14" stock steelies. Nothing cleared it.
Anybody else have this problem? Or a remedy for it?
Just my young gun two cents.

Mike
 
Aint that the way it goes ? inexpensive upgrade in one thing leads to an expensive upgrade in another. I think you will meed aftermatket wheels at 17 inch.
 
I'm in the process of doing this swap now on my Dakota with a 8.75, but I'll be running 20" wheels out back. I'll also most likely run a 20" wheel and drag radio combo. I'm pretty sure the Grand Cheerokee's have 17' wheels stock as well. This is most likely the issue.
 
MTAndrews did a really good post on this. I don't recall what he did for wheels. Maybe he'll chip in here.
 
Hmm..I wouldn't have thought 15" wheels would have a problem clearing 11" rotors, especially since the B body 11.75" front rotors clear 15" wheels fine.

I guess I am gonna find out. ](*,)

Luckily I have very little $$ in Jeep parts (all junkyard stuff at this point). I did the smart thing and ordered my new axles with standard registers and IF the jeep junk fits, I will just grind out the rotor. I am also running Draglites, so that may effect fitment.
 
Hmm..I wouldn't have thought 15" wheels would have a problem clearing 11" rotors, especially since the B body 11.75" front rotors clear 15" wheels fine.

I guess I am gonna find out. ](*,)

Luckily I have very little $$ in Jeep parts (all junkyard stuff at this point). I did the smart thing and ordered my new axles with standard registers and IF the jeep junk fits, I will just grind out the rotor. I am also running Draglites, so that may effect fitment.

I think the problem is in the height of the caliper. Those front calipers have a very low profile.
 
I went ahead and got to work fitting the back plate on the axle.

Jeep back plate center hole: 2.81"
A-Body housing diameter: 2.85"

I needed to open up the hole on the back plate just a little. I used a stone wheel on my angle grinder and opened it up just enough to get the back plate on. It is a very tight fit...no hammer needed, but no slop either. Also opened up the dust shield.

One issue I did have was the bolt holes. I couldn't tell if they were slightly off on the back plate, or a different diameter (metric?). The holes in the back plate were 25/64. I just reamed them out ever-so-slightly with a 13/32 bit and the plate fit.

With the backplate, dust shield, caliper carrier and housing installed, I bolted up a wheel ( Weld Draglite 15x8 ) and checked my clearance. No issues whatsoever. I was easily able to reach in and slide my finger between the caliper bracket and wheel. Mind you the wheel is bolted right to the flange....there is no brake rotor installed, which would actually push the wheel out another 1/8" maybe. If my wheel flexes that much I have some serious issues.

Withtire.jpg


Frontside.jpg


Backside.jpg


Clearance.jpg
 
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