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8.25 disk brake swap

Jeepguy91

Jeepguy91

NAXJA Member
NAXJA Member
Location
Warsaw, IN
We are planning on getting our parts to do the zj disk brake swap on our xj and want to make sure we are getting exactly what we need. I haven't found anywhere what axle the brake parts can come from. Does it matter if its the Dana 35 or the Dana 44? I think that is about the only thing that I really haven't gotten all the info on. Just need to know what axle to get them from.

Thanks,
Ben
 
I'm pretty sure i got mine off a ZJ with a D35.

Not even sure if ZJs came with a D44.

You honestly only need the backing plates. I bought new calipers and pads and rotors. Just be sure to grab the calipers from the Junkyard as there is a core charge on them and you can get some of your money back if you decide to buy new calipers.
 
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You can get the ones from the dana 35 or the 44a they are all the same. Don't to grab the internals from the proportioning valve too. Be careful you don't lose the little spring inside. If you are just grabbing it from a junkyard then get the whole proportioning valve and then worry about pulling the guts out of it when you get home and can disassemble it on a bench.
 
a>
After installing the thicker ZJ rotors, I found the 8.25's wheel studs were too short, when used with Factory alloy wheels.
I got a new set of longer studs, from Napa, same size as the front hubs.
You could also use the studs from the ZJ donor or punch them out of a set old front hubs.
http://www.flickr.com/photos/lwade/4379679967/in/set-72157605049387729

4379679967_b585082d51.jpg
 
Not sure if you are interested in the Libby Disk conversion but here is what I did .

I Used the disks from a Libby with the 8.25 rear axle with libby e-brake cables .
I got the backing plates online from a wrecking yard since I couldn't find any local and got the rest New.

I used the ZJ soft brake lines because they screw right into the libby caliper and the stock XJ metal line.
The libby Lines are crimped where it turns into hard line instead of being two piece like the xj and zj so they would be more work for no reason .

The only thing I would do different is I paid good $ for new libby e-brake cables and one side is long .
It is in a big loop zip tied up out of the way and causes no issues.
However someone posted some in my build thread that are cheaper and a more appropriate length.


The Lugs are long enough but I have steel D-Windows not the stock rims .

I didn't do the Prop valve and still had greatly improved braking .

i am not sure wich are more effective the Zj or Libby Disks , but the minor inconvenience of widening a hole on the Zj is the only real install difference Afaik .
 
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The disks themselves are almost identical ... And the same as the TJ disks I used. The calipers are the same. Really for my swap it came down to what I had available.

I used ...

95 ZJ backing plates
06 TJ calipers
06 TJ pads
06 TJ rotors
95 ZJ parking brake shoes
06 TJ brake hardware kits.
 
Make sure you swap wheel studs! It was pointed out to me yesterday when rotating my tires that I have less than 1/2" thread engagement in my lugs! The tech as Discount Tire said each lug should have 10 full turns before tightening down... I have 4.

I have the Libby axle shafts from my donor axle, but I haven't checked to see if the studs are compatible with TJ Canyon wheels. I suspect they are, but I won't speculate. Either way, looks like I found my next project!
 
lazyxj said:
You could also use the studs from the ZJ donor or punch them out of a set old front hubs
Click to expand...

do NOT re-use wheel studs, they are meant to be installed once. when you punch them out and put them in again somewhere else the knurls on them are already smashed down. just think for a minute how much of a pain in the ass it would be to take off a lugnut if the stud was spinning in the hole.
 
Mega bump for this thread:

Anybody know what size studs for bolting the zj backing plate onto the c8.25? I know they need a different size (longer?). I've had some junkyard parts sitting in my garage forever and just got around recently to cleaning them up. I'm rebuilding the calipers and have pads and e-brake shoes. Still need to grab some longer studs, rotors, and then figure out the e-brake cable solution.
 
DeftwillP said:
Mega bump for this thread:

Anybody know what size studs for bolting the zj backing plate onto the c8.25? I know they need a different size (longer?). I've had some junkyard parts sitting in my garage forever and just got around recently to cleaning them up. I'm rebuilding the calipers and have pads and e-brake shoes. Still need to grab some longer studs, rotors, and then figure out the e-brake cable solution.
Click to expand...

When I Did Mine I Went To The Dealership And Picked Up Kj Liberty Studs. They Are Yhe Same Press To Fit Size Just longer
 
Yeah, the consensus seems to be that 99+ front studs, zj studs, or kj studs would work. I'm not too concerned with that so much as the bolts for the backing plate to the axle housing.
 
DeftwillP said:
Mega bump for this thread:

Anybody know what size studs for bolting the zj backing plate onto the c8.25? I know they need a different size (longer?).QUOTE]

Yes, a bit longer, You're going from mounting a piece of tin to the axle to a cast iron support plate for the discs. So figure on another (EDIT) 1/4".
I went down to the local Farm and Fleet and picked up some. Grade 5. I dont recall the diameter. The writeup for 8.25 Discs to a 8.25 axle (From a Liberty) says to just use the Liberty ones.
Should be the same backing plate, just a smaller axle tube hole on the ZJ.

~Ron
Click to expand...
 
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