XJ 44 Build Redux

Alright, so this is the second incarnation of this type of axle to go under the rig. Little backstory here, I'll show you version one.

Here is the start of the first one.



I set is up with Superior 4.88s, Detroit TruTrac, Alloy USA Alloys, and TeraFlex Discs.







The Tera kit didn't last long. I don't have the pics handy at the moment. But basically the spacers deformed, pushed the backing plates in to the rotors and just destroyed the kit. I sold the backing plates and alloys to a friend at that point and just threw the stock drums and shaft back on.

A couple months later I hit the road for Colorado Fest 2007 at the end of July that year. We were about 10 miles out of Montrose headin' down the highway when the back starts poppin bad. My first thought is I spit a joint on the shaft. Just as I start to tap the brakes and move right, off the road, the rearend locks up. Did a 180º spin off the highway at 70 mph. Slid right into someone's driveway between a 6' deep drainage ditch on either side of it. Had my angel with me that day.



Basically the TT has a block that serves as a centerpin. It just bolts in to the TT. When my installer setup the gears, he (speculating here) saw the block was already bolted in and didn't check the torque spec on it. So after time it worked it's way loose. Until right outside of Montrose it let go and sent that chunk of steel bouncing around in the diff. Chewed teeth off of both gears, twisted the splines, and took out a chunk of the inner webbing. The drivers side end flange also had an incurable leak, so I just scraped it.











Well my XJ was my DD at the time and I needed to be mobile asap. So after we got back from the trip we swapped a D35 under. I drove this way, without 4x4 for a little more than a year. In the meantime I acquired another stock 44 and started over.

End result is as follows:

Powder Coated Semi-Gloss Black
33 Spline Alloy USAs
ARB
Precision 4.88s
Yukon U-Bolt Yoke
Crane Cover
Wilwood Disc Brakes
Custom Stainless Braided Lines
M.O.R.E. Ebrake Cables







:guitar:

I'm digging the brake setup, any more info on what was involved doing the wilwoods?

Nice job

Imjosh said:

I'm digging the brake setup, any more info on what was involved doing the wilwoods?

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Yeah, I bought them and bolted them on........

Kittrell said:

Yeah, I bought them and bolted them on........

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Sorry I thought since this was the tech section you might wanna give some more info on it, my mistake.

Imjosh said:

Sorry I thought since this was the tech section you might wanna give some more info on it, my mistake.

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Well what would you like to know? There was no modification, I took them out of the box and put them on the axle. You asked what was needed, and there was nothing needed. Figured my answer eluded to that.

That's about as much tech as one can give on how to bolt on brakes. Maybe a service manual could be of help to you?

Is it a kit available from wilwood or is it a kit that someone else puts together?


I don't need a how too on discs brakes, excuse me if my original post wasn't specific enough.

Imjosh said:

Is it a kit available from wilwood or is it a kit that someone else puts together?

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There is no "kit" available for a "XJ 44". But we got lucky. XJ 44s share the same flange pattern as the small bearing Ford. And lucky yet again that the XJ brake backspace is 2.5". The Ford small bearing came in two backspaces, one of them happens to be 2.5". So basically the only difference between a Small Bearing Ford end flange and an XJ end flange is that the shafts use different bearings. So you just order the Wilwood kit for a Small Bearing Ford and a 2.5" backspace, it will bolt right on.

Also on a technical side note. I believe that my Tera brakes failed due to a warped spacing ring. But I believe it warped because it was too large. Every swap I have ever read about, for putting disc brakes on a XJ 44, included a custom spaced ring. This ring was included with my Tera kit. I had everything installed and bolted up. However it looked as if the retaining plate was bowed in the middle. I wasn't too sure how it was supposed to go together and I could not 100% tell with everything mounted up. As the space to get to the retaining plate is almost inaccessible with the internal ebrake hardware. So I just ran it as is, and the brakes failed. When I put it back together, I ditched the separate ring and plate and had the rubicon retainer plate modified to fit the XJ end flange. When I bolted the shafts back in, same thing, retainer plate with the built in spacer ring was visibly bowed out in the middle. About a week later I took the discs off and went back to the stock drums.

Now fast forward to a year later. Installed everything and the rotor is very hard to turn. I had the rubicon plates modified again, and went that route. Wilwood sent some retaining plates, but the lip was considerably less than the Rubicon plate, ergo I did not use them. There is a visible gap between the backing plate and the end flange. The gap is on both side and not consistent. Realizing that the retainer plate and the axle seal are responsible for the gap we are seeing, we take it back apart. And here is what we discover. The seal for the set 10 bearings used on the XJ shaft protrudes past the end of the flange. Coupled with the depth of the spacer, the retainer plate is pushed very far out. I cut the rubicon plates off and used the supplied Wilwood plates. Everything spun freely and worked as it was supposed to. Now I am not going to say that Tera Flex, MadXJ, etc. are all wrong. But in my personal experience, that spacer is too large and does not work as intended.

Rubicon retainer plate against a seated set 10 bearing seal. The gap seen here is almost twice as thick as the backing plate.

Thanks

Imjosh said:

Thanks

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No problem, I'll dig up the part number if I can.

Edit: Got it, 140-9282 or 140-9282-D for drilled rotors. It's the Dynalite Pro Series

Back when I bought them, I went through Revolution Brake. I had a good experience with them.

Revolution

However, it looks like Summit has the best price at present.

Summit

Great info DJ, thank you! I'm starting up a D44 build, so I'm finding this info particularly interesting. I might have to hit you up when I get around to doing it. :thumbup:

So... I take it you didn't need to do anything with your master cylinder or anything like that? Do the discs provide a substantial increase in stopping power of the drums?

Wow, huge calipers compared to the TJ units. Prop valve mods?

XJEEPER said:

Wow, huge calipers compared to the TJ units. Prop valve mods?

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Not yet. The braking is better than the drums. But I can't even get close to locking them up, or hugging the steering wheel. I am thinking prop mods are in order. Maybe something along the lines of the adj. Wilwood piece.

XJEEPER said:

Wow, huge calipers compared to the TJ units. Prop valve mods?

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Proportioning valve... that's what I meant, not master cylnder. :doh:

I have been following my old XJ's progress with the new owner. Here is some solid information regarding the Wilwood kit. This is need to know for anyone who might be considering the kit.

T&A-XJ said:

So it has came to my attention that the Wilwood disc brake kit is NOT a bolt on deal. While it is close and will work right when everything is perfect, there are some issues that should be adressed for our imperfect real world.

1st of all: The Wilwood supplied axle bearing retainer plates do not have a deep enough lip to tightly seat the axle bearing and seal. The stock plates are flat to use in conjunction with the drum brake backing plates that are .125" thick. The Wilwood backing plates are .25" thick and are supplied with retainer plates with a .0625(1/16th") lip. This leaves a .0625" gap allowing the axle shaft, bearing, seal and rotor to shift back and forth. While .0625" of play doesnt seem like much I believe it damaged the seals and the gap increased over time. When I removed the shafts last week there was over 1/8" of end play. Again doesnt seem like much however, due to the extremely tight tolerances on the non-floating brake caliper it created a big problem.
Simply put the old backing plates are .125" the new Wilwood backing plates are .25" thick for a differance of .125" so the retainer needs to have a .125" lip to correct the issue.

2nd issue: The rotor was already offset to the outside and almost in contact with the caliper. In a perfect world the rotor should be centered in the caliper as to allow both sets of pistons (on either side of the rotor) to travel the same distance away from the caliper and clamp the rotor. This did not seem to cause any issue I noticed but in the event of a bearing failure, possibly a warped rotor or in this case the issue above^^ and instead of the pistons taking up the slack it was transitioned directly to the caliper and its bracket. Over time this fatigued the bolts which hold the bracket on and snapped them off...

Fix for issue #1: At this point I have not located a bearing retainer with .125" lip to keep proper pressure on the bearings so I am having a set of Rubicon retainer plates #5083678AA machined down to have the needed .125" lip. The Rubicon plates have a .225" lip which having tried is much to thick and will not work.

Fix for issue #2: The Wilwood kit has a spacer between the backing plate and the caliper mounting plate. The supplied spacers are .482" in thickness and I will be having these machined down to .388" to move the caliper outward and center the rotor.
For those interested the opening in the caliper is only .1875(3/16th") wider than the rotor.

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I am running the rubi plate with crown vic brakes... hopefully its not messing anything up.

ausi02 said:

I am running the rubi plate with crown vic brakes... hopefully its not messing anything up.

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I ran the rubi plates with my first 44 on the Tera Flex brake kit. The spacers they supplied were the same width. The Rubi plates were too thick then. When you torque the plates down, they start to bow. This happened with their spacer and a stock D44 retainer. A redrilled rubi retainer, and again with a rubi retainer and my Wilwood kit. You can see it here.



I don't know who came up with that spacer dimension. But in my experience, it is too deep for the XJ D44.