WJ Swap

Deadman 94 xj · May 6, 2010

I just got done with it. For those interested in this, there's a lot of talk about re-drilling the WJ rotors to fit. I didn't like that idea so came up with 96 Crow-vic rotors which worked perfect with 99 unit bearings.

Here's a great writeup:
http://www.jcroffroad.com/WJ.html

I went over the knuckle with mine. Doing it this way allowed the track bar and drag link to end up about perfect. No bump steer or DW with this setup and it seems to travel a little better. Maybe because there's less opposing forces between the two bars now.

1996 Crown-vic rotors:

Knuckles need to be reamed if you're using one ton TRE's

On a scale of 1-10. The stock brakes, running 35's, were a 4. After the swap the brakes are easily a 10

. I still need to replace the steering with DOM and tube adaptors so there's not so much exposed thread on the TRE's.

Shown here is the JCR steering. The WJ swap tightened it up like it was when it was stock.

XJPhoenix · May 6, 2010

Nice!

Just a couple of questions... Did you have to weld a spacer on? Or did you just use 99 XJ unitbearings bolted straight to the knuckle (and the Crown Vic rotors)? Any caliper/rotor troubles? Did you use the stock calipers?

Deadman 94 xj · May 6, 2010

Thanks.

I did weld the JCR spacer to the knuckle. I don't think there's a way around that one, unfortunately. Make sure the welds are good because this spacer becomes what holds the unit bearing in place, along with the three bolts. I don't think it's extremely critical, but something to keep in mind.

I also put .25" spacers between the caliper bracket and where it bolts to the knuckle. You can either weld the spacers in place or use 2 .50" washers, stacked, on each bolt. There are 2 bolts / caliper.

After doing that, the caliper slid right on the rotor like it was stock. No troubles at all.

I used the Teves calipers and Napa premium pads.

Wheels are 15" with 3.75 back spacing. No problems with fitment there at all.

The only reason I mention the 99 unit bearings is because there's a depth difference between those and the earlier models. I'm not positive it wouldn't work with a pre-99 bearing but this is what I did and it worked perfectly.

Rotor comparison:

1999 WJ rotor:
# of Bolt Holes : 5
Bolt Circle Diameter : 5"
Brake Rotor Diameter : 12"
Brake Rotor Discard Thickness : .97"
Brake Rotor Thickness New : 1.03"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.84"
Height : 2.5"
Maximum Lateral Runout : .004"

2002 Crown vic rotor:
# of Bolt Holes : 5
Bolt Circle Diameter : 4.5"
Brake Rotor Diameter : 12.44"
Brake Rotor Discard Thickness : 1.01"
Brake Rotor Thickness New : 1.11"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.83"
Height : 2.59"
Maximum Lateral Runout : .004"

2003 Sport track Rotor:
# of Bolt Holes : 5
Bolt Circle Diameter : 4.5"
Brake Rotor Diameter : 12.01"
Brake Rotor Discard Thickness : .97"
Brake Rotor Thickness New : 1.03"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.84"
Height : 2.6"
Maximum Lateral Runout : .004"

And just for shits & giggles
the stock 2000 cherokee rotor:
# of Bolt Holes : 5
Bolt Circle Diameter : 4.5"
Brake Rotor Diameter : 11.03"
Brake Rotor Discard Thickness : .89"
Brake Rotor Thickness New : .96"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.84"
Height : 3.06"
Maximum Lateral Runout : .004"

_______________________________________________________

I wanted to use the 02-03 sport tracks but they wouldn't accept the unit bearing. So I went with the 96 Crown vics.

1996 Crow-Vic
# of Bolt Holes : 5
Bolt Circle Diameter : 4.5"
Brake Rotor Diameter : 11.45"
Brake Rotor Discard Thickness : .98"
Brake Rotor Thickness New : 1.03"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.83"
Height : 2.6"

XJLI · May 6, 2010

Nioce.

good info.

kastein · May 6, 2010

Just FYI, the 99 unit bearing bit isn't quite right. It was a mid year switchover, 99.5 or so up are the unit bearing you're using, 99.5 down are the other one.

'00 and '01 and probably other year TJ unit bearings are the same as 99.5 up XJ unit bearings.

Deadman 94 xj · May 6, 2010

Regardless of the mid-yr bearing switch, 99 unit bearings are the late bearings according to my local NAPA. I placed a 99 bearing and a 97 bearing side by side and saw the difference. I just happened to be running late model bearings anyway so this just happened to work out.

kastein · May 6, 2010

NAPA is wrong then. I have personally pulled 98-down (and 99.5) style unit bearings from a 99 after comparing them to a 2000 sitting next to it at the JY. The parts catalog agrees, ask the dealership for a printout of figure 005-210 from the 97-99 catalog. Unit bearings are listed as one part number for "composite rotor (1997-1999)" and another for "full cost rotor (1999)" which indicates both types were used in 1999.

NAPA's system will also tell you that all XJs came with a 3 speed Chrysler automatic, and give you a completely wrong filter/gasket kit intended for the 30RH or A999/904. It has no idea the AW-4 ever existed, I had to look it up on RockAuto and then go back and ask for the specific part number I needed. I don't trust their computer system any further than I can throw it, luckily I caught that before I'd dropped the pan on my (at the time) only vehicle!

Deadman 94 xj · May 6, 2010

Well, it's safe to say that 2000 and later unit bearings are what I used here.

Deadman 94 xj · May 6, 2010

Correction:

What kastein posted is correct. I used what I thought were the late model bearings but after doing a little research, they are 99 bearings used for composite rotors. So that would be 99.5 earlier if I'm right.

This is what happens when you have a 97 axle on a 96 cherokee and were told that the axle had late model bearings on it. I guess I thought I was buying late model bearings all this time!

That said, either bearing should work. You may not need the spacers between the caliper bracket and the knuckle if you use the late 99.5 and newer unit bearings. I would go ahead and use these bearings anyway though because the rotor may come in contact with the knuckle.

Shown here is the 1999.5 to 2001 unit bearing on the left, 1990 to 1999.5 unit bearing on the right:

You can compare the pick above of the bearing I used with the bearing on the right of this pic. Looking at the center measurement, you can tell that the one on the right is what I used.

Sorry for the misinformation.:rof:

BarFlyFisherman · Jul 22, 2012

Deadman 94 xj said:
Thanks.

I did weld the JCR spacer to the knuckle. I don't think there's a way around that one, unfortunately. Make sure the welds are good because this spacer becomes what holds the unit bearing in place, along with the three bolts. I don't think it's extremely critical, but something to keep in mind.

I also put .25" spacers between the caliper bracket and where it bolts to the knuckle. You can either weld the spacers in place or use 2 .50" washers, stacked, on each bolt. There are 2 bolts / caliper.

After doing that, the caliper slid right on the rotor like it was stock. No troubles at all.

I used the Teves calipers and Napa premium pads.

Wheels are 15" with 3.75 back spacing. No problems with fitment there at all.

The only reason I mention the 99 unit bearings is because there's a depth difference between those and the earlier models. I'm not positive it wouldn't work with a pre-99 bearing but this is what I did and it worked perfectly.

Rotor comparison:

1999 WJ rotor:
# of Bolt Holes : 5
Bolt Circle Diameter : 5"
Brake Rotor Diameter : 12"
Brake Rotor Discard Thickness : .97"
Brake Rotor Thickness New : 1.03"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.84"
Height : 2.5"
Maximum Lateral Runout : .004"

2002 Crown vic rotor:
# of Bolt Holes : 5
Bolt Circle Diameter : 4.5"
Brake Rotor Diameter : 12.44"
Brake Rotor Discard Thickness : 1.01"
Brake Rotor Thickness New : 1.11"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.83"
Height : 2.59"
Maximum Lateral Runout : .004"

2003 Sport track Rotor:
# of Bolt Holes : 5
Bolt Circle Diameter : 4.5"
Brake Rotor Diameter : 12.01"
Brake Rotor Discard Thickness : .97"
Brake Rotor Thickness New : 1.03"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.84"
Height : 2.6"
Maximum Lateral Runout : .004"

And just for shits & giggles
the stock 2000 cherokee rotor:
# of Bolt Holes : 5
Bolt Circle Diameter : 4.5"
Brake Rotor Diameter : 11.03"
Brake Rotor Discard Thickness : .89"
Brake Rotor Thickness New : .96"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.84"
Height : 3.06"
Maximum Lateral Runout : .004"

_______________________________________________________

I wanted to use the 02-03 sport tracks but they wouldn't accept the unit bearing. So I went with the 96 Crown vics.

1996 Crow-Vic
# of Bolt Holes : 5
Bolt Circle Diameter : 4.5"
Brake Rotor Diameter : 11.45"
Brake Rotor Discard Thickness : .98"
Brake Rotor Thickness New : 1.03"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 2.83"
Height : 2.6"

Did you use Teves calipers for a 1996 Crown Victoria as well?
Did you require the Crown Victoria's caliper mounting brackets as well?

RNMedic · Aug 9, 2013

old post, new question. with the 96 rotors do you get full pad contact???

VAhasnoWAVES · Aug 10, 2013

Deadman 94 xj said:
I did weld the JCR spacer to the knuckle. I don't think there's a way around that one, unfortunately. Make sure the welds are good because this spacer becomes what holds the unit bearing in place, along with the three bolts. I don't think it's extremely critical, but something to keep in mind.

just for clarification...

WELDING THE SPACER TO THE KNUCKLE IS CRITICAL.

the load of the hub is on the bore fitment, NOT the bolts. i forget the exact numbers, but with the 1/4" spacers there is very little fitment of the unit bearing into the knuckle itself. not welding the spacer to the knuckle is asking for a disaster.

WJ Swap

Deadman 94 xj

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XJPhoenix

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Deadman 94 xj

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XJLI

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kastein

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Deadman 94 xj

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kastein

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Deadman 94 xj

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BarFlyFisherman

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VAhasnoWAVES

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