Disc Brake Change Over

[Jeepster19]

Can anyone give me the specific year span on the Grand Cherokee disc brakes that will fit my 98 Xj?I thought the jeep liberty would fit also,correct me if I'm wrong.I'm only asking because I don't want to pick the wrong year and waste my time& money.My Xj has a Chrysler 8.25 as shown.http://i573.photobucket.com/albums/ss179/jeepster19/c2e3d71b00008849bee4cac7b35344c2.jpg

[xjrev10]

To add to this question...

Will disc brakes off a Aluminum D44 ZJ work on a 8.25? I would guess the tubes are the same on the 44 as on the 35 so the center holes on the backers will still have to be hogged out...

To the OP:

Yes. Libby brake parts are direct bolt on. Backers, rotors, calipers. ZJ parts do take some mods to the backing plates do to a D35 having smaller axle tubes then a 8.25. 8.25 has 3" tubes. I believe D35s have a 2 3/4" tube..

[nickxj94]

it dont matter on year i think 96 to 98 i got mine from a 97 zj, and yes the liberty will bolt right up.

[07Negative]

The ZJ is not just a simple bolt in. There is a little more work involved. That's why Teraflex has their kit. Which is 98 Ford Exploder parts.

[89Laredo]

Buy an 8.8...
Honestly if you do it cheaply I think you would have about the same amount of money into it. Theyre cheap.

[nickxj94]

Buy an 8.8...
Honestly if you do it cheaply I think you would have about the same amount of money into it. Theyre cheap.

I would have done the 8.8 with disc but there made of gold down here in Arkansas cheapest one I could get even at pick and pull was $250.00 and I had to pull it. So I got the Zj stuff for $90.00 got lucky and it had new pads and ebrakes And rotors :D

[89Laredo]

I got one swap ready and welded for 200.

[bluedragon436]

I would have done the 8.8 with disc but there made of gold down here in Arkansas cheapest one I could get even at pick and pull was $250.00 and I had to pull it. So I got the Zj stuff for $90.00 got lucky and it had new pads and ebrakes And rotors :D

Yeah I'll def be going the ZJ route, as 8.8's here are not cheap at all, even pulling them yourself from the JY.. Then I still got to get all the brackets and have someone weld them all one... In the end for me the ZJ conversion will work just fine and be cheaper in the end... especially cause regardless which build I did, I'd still replace the rotors, pads & shoes on the rear end to make sure they are for sure good.. unless I hit a kick ass deal like you did Nick with the new parts already there..

[07Negative]

8.8 is over rated. And it's too narrow. You want to avoid running spacers. If you're on 33's or even 35's, build up a 8.25 and your fine. Just build your 8.25" unless you damn well know you're going to be mashing on it with some 35's or larger. Sure you'll be $2500 into, but so what. Besides, its the front that's weaker of the 2 axles. Wait until you build or buy a front axle. You'll be selling your limbs to make it happen.
I think people just read into the hype of what others are doing and think they need to do the same thing and they don't even wheel much nor do they wheel like some of the cats running larger axles.

[Jeepster19]

it dont matter on year i think 96 to 98 i got mine from a 97 zj, and yes the liberty will bolt right up.

Any idea on the year range for the liberty?The backing plates will fit on with no modification?What about the parking brake cables& the proportioning valve?

[Jeepster19]

The ZJ is not just a simple bolt in. There is a little more work involved. That's why Teraflex has their kit. Which is 98 Ford Exploder parts.

No ford parts for me on my Xj,it will break down for sure!!!Lol

[07Negative]

You can use from 02' to 06' liberty. The backing plate is 3.8" while the XJ is a 1/8". You'll need longer bolts by about a 1/4". That's pretty much it.
Your Jeep wont break down b/c of a rear brake conversion. But I can understand your opinion on Fords. You have a Toyota transmission.
Before swapping brakes. Look for stats on piston size. Also don't forget to pick up a proportioning valve from a ZJ. You'll need the guts from it. Or you can buy a new adjustable valve. The piston size is the same as the ZJ as it is on the Liberty.

[Jeepster19]

Will a 99zj parts work?There is a guy who is parting one out,I just want to make sure the zj stuff will work before I buy,if I decide to go the Zj route.Will the parking brake cables work off the liberty or will I have to get them from something else so they will hook up?

[Ringo]

I have installed an 8.8 in my 1999 xj. If you are energetic and have some money in my opinion it was worth it. Parts availability out the wazoo. Mine came out of a 1999 mercury mountaineer. I also used the rims off the mountaineer. The rims have the correct bolt pattern same as the XJ and rim offset was perfect. Clearance all around. I installed a new ring & pinion to match the front diff. Installed new kevlar clutch pack in the rear and bam, good posi action. Their are other things you have to do when installing any disc brake conversion setup. proportioning valve has to be switch from conventional brake system to disc brake proportional valve system. the Pressure is needed to be higher to actuate the disc brake. The conventional brake drum uses less pressure to operate. Haven't broke a Ford rear yet and run 650 hp in my 69' camaro at 9.9's in the quarter. Got to give it to FORD on this one.

[07Negative]

I'm not sure about the 99'. I've read about 94-98.

[Jeepster19]

I've heard the same too.If anyone knows if the 99 will work,let us know.Knowledge is power!:D:D:D

[XJ Wheeler]

I'm not sure either but the '99 grand is a WJ, ZJs ended in '98. Just to clarify.

[Jeepster19]

Thanks for the info.:D:D:D Nows it's time to find a donor!:D

[bigjim350]

Somebody said that the ZJ D35 rear disc isn't just bolt on to the 8.25. True, but it is still SUPER simple. All you have to do is use a die grinder (or whatever you can find) to open up the hole on the backing plate so it fits over the axle tube. Also it by no means has to be a perfect hole, the bolts will center it up just right. Also I have no idea if the wj d44 disc work, but if they did im sure it would be easy to find a writeup about it, which it isnt....

[4.3LXJ]

WJ D44 are a different animal. They have a little drum brake inside the disc for the electronic positraction

[07Negative]

Disc brakes wont fix a already shitty situation. If the drum brakes are working the way they are intended to. Disc conversion is completely pointless. If you've got 31" tires on stock axles and your braking system is dialed in. Maintained the way it should be. I'd be hard pressed to have someone tell me they can tell the difference between the two. Let alone make it worth their time and money.
But chances are if the OP is anything like many of us. He's not doing Hells Gate on his way to work. And if he was. Then there are other things to consider. Even if you're a concerning individual wanting better stopping power. There are indeed other was about it.
I'd like to see a actual and factual stat on stopping power with a rear disc conversion to make it worth the while. What about brake torque or thermal capacity? What if a single piston caliper doesn't equally distribute force on a brake pad across the surface of a rotor? I don't know what that's called. Doesn't a drum shoe make more positive contact under force than a single piston caliper?
So why not look at other components of the braking system? Your asking a OEM braking system to perform outside of its limits (depending on the particular setup of course). Sure a 29" tire vs a 30" tire might not have much of a impact on a OEM setup. But beyond that? Even if you equate the tread type of the tire. I'm sure there is some difference. Now blow that up to what some of us are doing. 33's or 35's with mud terrain. Disc are not going to make a difference on their own. Brake fluid temp goes up. The higher it goes the less efficient it becomes etc.
If I'm not mistaken. An XJ's braking is codependent on its steering setup. The pump at least.

[bluedragon436]

From what I read most of the 99's have the Aluminum D44 which is why they don't list the 99ZJ as a swap option.. I would think if it still has the D35 then you should be fine with using the brakes.. I don't see why they would have changed the brakes on the D35 for the last year they used it.. I know that it is said the 99 is the WJ only, but I have three people I work with at work that have ZJ's and their titles say 99 on them... so I'm assuming this is what you're going off of when you ask if your friends 99 ZJ that he is parting out will work..

[Jeepster19]

I've heard that the disc brake kit from teraflex is basically ford explorer parts.Has anyone ever tried the parts off an explorer?I thought they had a 8.8 rear axle.I was just wondering because there is a guy parting out a 98 explorer locally.

[bigjim350]

The backing plate on the 8.8 has a different bolt pattern where it mounts to the axle. You could re-drill the holes on the backing plate and make it fit though. I think the terraflex kit comes with a d35 disc brake backing plate, with 8.8 calipers and rotors.

[xjrev10]

WJ D44 are a different animal. They have a little drum brake inside the disc for the electronic positraction

What about the ZJ AD44?

[4.3LXJ]

Not sure. I know about the WJ 44 because I had a wrecking yard try to succor me into buying one for a huge amount of money because it had a "locker" in it