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MJ D44


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so saw this link: viewtopic.php?f=4&t=18653

 

which brought me here: http://www.jeepforum.com/forum/f126/mov ... rs-864839/

 

thanks to wahoosteeler, sent the seller an e-mail and he said its in a garage and I can come look at it. he is also going to send me some pictures. if the pictures look good i'm most likely going to get it. (it has 3:55's which is what i am looking for)

 

anyways, the real question is this: He said that the axle does not have any brakes on it, but he is also selling "ZJ backing plates, e-brake hardware and calipers, maybe even hoses. Just pick your favorite pads and rotors."

 

so do I want to get that also? or can i get drums to set up with?

 

$100 bucks sounds like a deal. but if I can't get brakes..

 

Daddio doesn't like the idea, but I thinks its a good one.

 

please leave feedback.

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Our 96 ZJ on 30's stops ALOT better than the 98' XJ on 31's.

 

Ft brakes are identical, rears are ZJ discs vs 9"x2.5" drums for the XJ.

 

I'd give a braking advantage to the ZJ rear disc setup,

 

but the ZJ's emergency brake setup is junk (IMHO).

(little tiny brake shoes inside the rotor hat).

 

Just had to crank the adjusters down (= dragging), just to get it to pass inspection.

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I don't know what he's smoking, but disc brakes don't use backing plates. If it were me, I'd pay the cheaper price and skip the partial disc brake stuff he has, and use the money to put stock 10" x 2-1/2" drums on it, the way it was meant to be. I'm sure that's a minority opinion among you young whippersnappers who didn't grow up during a time when drum brakes were not only adequate, they also worked. The problem with drums in recent years is that the manufacturers started skimping, so they made 'em too small to stop the vehicles they were on.

 

THe primary advantage to discs is cooling, for less brake fade. That's a factor only if you race, or if you drive a LOT in mountainous terrain. For normal purposes, the MJ D44 10" x 2-1/2" drums provide PLENTY of braking. And they don't require changing the booster and master cylinder, which would be necessary to get the discs to work properly.

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The ZJ rear disc brakes do use backing plates. They double as dust shields for the main (disc) brakes, but they are backing plates for the parking brake, which is a tiny little drum brake inside the rotor hat. No backing plates/dust shields, and there's nothing for the parking brake to mount to.

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i see any brake upgrade as a good upgrade for the xj/mj of early model years.

The "standard" rear drums for the XJ/MJ in the "early" years (through 1989) were 10" x 1-3/4". After 1990 Chrysler went to 9" x 2-1/2" ... wider, but the contact surface was located 10 percent closer to the center of rotation, so the larger brakes had a shorter lever arm. Dumb.

 

In short, the D44 10" x 2-1/2" drums ARE a huge upgrade over either of the "standard" drum brakes on the XJ/MJ.

 

Beyond that, both vehicles suffer from rear braking issues caused by their respective proportioning valves. In the MJ, the height-sensing valve doesn't let the rears do any work unless the bed is heavily loaded. That won't change if you switch to rear discs, and if you address it by removing or recalibrating the proportioning valve -- you won't need the discs. In the XJ, the proportioning valve gets gummed up and cuts off ALL braking to the rear wheels. Once again, changing to discs won't help, because they won't be doing any work, either. But they'll certainly look ultra-cool and high tech while they're doing squat to stop your vehicle.

 

If you feel a need to upgrade your braking, be sure you understand what part of the system isn't performing before you start throwing parts (and money) at it.

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I wouldn’t buy anything for any amount of money until I know exactly what I’m getting. The add says the axle is “as is” so, I suspect there are hidden problems, so are you able to rebuild if necessary? Or pay someone to diagnose and fix whatever the potential mysterious problem is? Photos won’t tell you much.

 

So my question would be, why even worry about an incomplete brake package? Good luck! :popcorn:

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The "standard" rear drums for the XJ/MJ in the "early" years (through 1989) were 10" x 1-3/4". After 1990 Chrysler went to 9" x 2-1/2" ... wider, but the contact surface was located 10 percent closer to the center of rotation, so the larger brakes had a shorter lever arm. Dumb.

 

In short, the D44 10" x 2-1/2" drums ARE a huge upgrade over either of the "standard" drum brakes on the XJ/MJ.

 

Beyond that, both vehicles suffer from rear braking issues caused by their respective proportioning valves. In the MJ, the height-sensing valve doesn't let the rears do any work unless the bed is heavily loaded. That won't change if you switch to rear discs, and if you address it by removing or recalibrating the proportioning valve -- you won't need the discs. In the XJ, the proportioning valve gets gummed up and cuts off ALL braking to the rear wheels. Once again, changing to discs won't help, because they won't be doing any work, either. But they'll certainly look ultra-cool and high tech while they're doing squat to stop your vehicle.

 

If you feel a need to upgrade your braking, be sure you understand what part of the system isn't performing before you start throwing parts (and money) at it.

 

 

 

While you are 100% correct in pointing out that there are many parts to consider while upgrading the brake system on any vehicle, I must say the rear discs (Explorer) made the super steep stuff we do out west way more safe when having to back down. My first (ignorant) experience with this was when I first got an XJ some years ago and immediately upgraded the rear axle to an 8.8 and without touching the prop valve, MC, or booster, I could stop WAY better and roll in reverse down steep angles with way better control than I could with the drums.

 

Today I have eliminated the factory MJ setup and run drums with an XJ prop valve and a WJ MC/Booster set up. I have an adjustable prop valve sitting here at the house waiting for my Rear D60 to go in with explorer disc brakes. :cheers:

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