Tips for '06 Rubicon axles into a '01 TJ

[waynehartwig]

I own AllJeep.com, and do several axle swaps each month. The most popular are Ford 8.8's and D44's put into TJ/ZJ/YJ/XJ's; in either my shop, or shipped to their respective home.

I registered just to chime in here. Most of you probably have no idea who I am, and some of you might think I have no idea what I'm talking about and will wish I just went away. Some of you will appreciate my experience, knowledge, and willingness to share it with you.

Swapping in D44 axles, front and rear, into a TJ with D30/35 combination is completely bolt in, other than the front driveline being too long and the possibilty of having the wrong u joints. ZJ's have no issues with driveline lengths.

The front D30 knuckles out (brakes, steering, etc) will bolt right up to a Rubicon D44.

The rear M35 (and even CHY 8.25" for you XJ guys) brakes (backing plate, etc) will bolt right up to any newer version D44. CHY 9.25" as well. The brake offset on these axles are the same, regardless if they are disc or drum. The stock TJ e-brake cables will work, with $5 worth of adaption parts; basically you loop the end and use a cable clamp.

In a drum brake TJ, the master cylinder and proportioning valve will need to be changed - yes, they are different! There are modifications that you can make to increase their usability, but you are also disabling their built in safety features. The drum brake master cylinder is different from a disc brake master cylinder, as they do have a check ball in them to keep fluid at the wheel cylinder. If this is used on disc brakes, it will cause them to drag and etc. With the correct parts, you will not need an adjustable proportioning valve.

The Rubicon D44 axles do not use D30, or M35 axle tubes! This is a nasty rumor that is completely false. If you don't believe me, the next time you have all four axles on your garage floor, get out the measuring tools and check it for yourself! The front D44 is a true D44, from inner knuckle (not including the knuckles - inner knuckles out are special for Jeep, not even true D30) to inner knuckle, includes the axle tubes, pumpkin and the pumpkin contents. The rear D44 is a true D44 all the way through. Both pumpkins have been machined differently to accept a different style of carrier than standard D44's. However, a standard D44 carrier will work in a Rubicon D44, but not vice versa.

I welcome all questions, and will answer them all. info@alljeep.com I will also sell you any and all parts you need to make this work, even complete axle assemblies custom built. I will also sell you another adjustable proportioning valve at cost if you seriously think it will help you, TJeeper. I also don't hide behind aliases (absolutley no offense to those that do use aliases for whatever reason), and use this same user name EVERYWHERE I register to. Ebay, PayPal, other forums, etc. So if you see this username elsewhere, chances are very good it is me. If you hear the name elsewhere, it is most likely me.

Anyway, flame on!

[scherf68]

I have not changed out the proportional valve and don't seem to have any problems. What should I expect or should be experiencing with discs in the rear now?

[waynehartwig]

I have not changed out the proportional valve and don't seem to have any problems. What should I expect or should be experiencing with discs in the rear now?

The proportioning valve only proportions the fluid, and stops fluid going to the rear, let's say, when a line breaks or is cut (for those of you with crazy ex wifes) - rather than losing all of your fluid each time you hit the brakes.

If you remove the rubber o ring, like others like to do, defeats this safety feature! and applies half of the fluid to the rear, and half to the front.

Since drum brakes have a smaller bore than a caliper does, you simply don't have enough fluid going back there. Replacing it with a valve from a 4 wheel disc vehicle, like a ZJ for example, will actually give you better braking performance. BTW, performance does not necessarily mean stopping power....

[scherf68]

so do I need to change it out? send me a quote for pv through pm. Thanks

[scherf68]

Also, how is the weather up there in Spokane, miss that place.

[TJeeper]

In a drum brake TJ, the master cylinder and proportioning valve will need to be changed - yes, they are different! There are modifications that you can make to increase their usability, but you are also disabling their built in safety features. The drum brake master cylinder is different from a disc brake master cylinder, as they do have a check ball in them to keep fluid at the wheel cylinder. If this is used on disc brakes, it will cause them to drag and etc. With the correct parts, you will not need an adjustable proportioning valve.

Since you are such an expert, maybe you could post up a picture of this "check valve" in the MC. Then maybe you could post the pictures of the difference between the MCs from drum brake TJs and disc brake TJs. And yes, I have disassembled both and do know what I talking about.

While you are there, maybe you could post some pictures showing the difference in the combo valves from a drum brake TJ and disc brake TJ. I have disassembled both of these also. Here's a hint: the residual check valve is in the combo valve, not the MC.

Patrick

[waynehartwig]

so do I need to change it out? send me a quote for pv through pm. Thanks

Yes, you should change out the PV, $100 to your door. This is a genuine Jeep part. You might be able to find one cheaper localy, in a wrecking yard or etc.

The weather up here is cold. I've been here for a bit over a month, and I can't remember the last time it was over 30*! We still have snow on the ground from the last storm almost 2 weeks ago, which only dropped about 4". ..Rooftops are also still covered.

[scherf68]

When I was stationed up there in 87-88 it didn't get over 20 degrees for 2 weeks, the trees were frozen icicles. Let me check in the yards first, will get back with you.

[waynehartwig]

Since you are such an expert, maybe you could post up a picture of this "check valve" in the MC. Then maybe you could post the pictures of the difference between the MCs from drum brake TJs and disc brake TJs. And yes, I have disassembled both and do know what I talking about.

While you are there, maybe you could post some pictures showing the difference in the combo valves from a drum brake TJ and disc brake TJ. I have disassembled both of these also. Here's a hint: the residual check valve is in the combo valve, not the MC.

Patrick

You are correct, the MC does not have the check ball in it and it is in the proportioning valve. My bad. I'll give you that one. However, the proportioning valves are different. Each one may physically "look" the same when you take them apart, but there are differences. Orifice sizes, check ball weights, etc.

[TJeeper]

You are correct, the MC does not have the check ball in it and it is in the proportioning valve. My bad. I'll give you that one. However, the proportioning valves are different. Each one may physically "look" the same when you take them apart, but there are differences. Orifice sizes, check ball weights, etc.

Try again. There is no check ball inside the combo valve. The residual check valve is a spring loaded mechanism with a brass fitting and a plastic ring. Both valves are the same size, and the springs are the same thickness with the same number of wraps. I did not measure the inside of the valve with a micrometer, but the ID of both the in line and out line are are the same.

This was hashed out about 4 years ago when the Rubis came out with the rear discs. There were quite of few of us who had done rear disc conversions and were curious how DC changed the system to compensate for the new rears. Obviously it makes sense they would change out the combo valve to reduce the residual pressure, everyone worried about the higher pressure causing the rear discs to overheat. The conclusion was DC didn't change anything.

The fact of the matter is my Jeep worked perfectly with the stock drum combo valve. No heat build-up with the rear discs, the F to R bias was perfect. I could press the brake pedal to the floor and not lock up the front brakes (a problem with 35s) and the rears would not lock up until the last few feet of the stop. I realize we all modify our Jeeps, and mine might not behave the same as someone else's, but until I read this thread, I had yet to hear about anyone complaining about the rear discs locking up first with an unmolested drum combo valve.

If you have some different information, post it up. Show the pictures of the different residual valves. The combo valves I have are from my '99 and from an '03 Rubi. Maybe someone sold me the wrong combo valve? Maybe DC changed it after '03? Who knows, but you are the first person to say they have seen a difference between the two valves, so show the proof so I can let others who are doing rear disc conversions they need to change out the combo valve.

[waynehartwig]

When I did my rear disc conversion with ZJ rear brakes, the original combo valve worked fine on my Jeep. I could only lock up the rear brakes at the end of a very hard stop- pedal to the floor.

If the rears are consistantly locking up before the fronts, you will need to plumb in an adustable proportioning valve..

They did have different part numbers.

Why do I need to take pictures or etc, when in this thread alone you have proved they are different. Trust me, I do not have an adjustable prop valve in my Rubi, and I do have 4 wheel disc brakes. FYI a prop valve only works in a panic stop situation, not slowing for a stop sign.

[TJeeper]

Why do I need to take pictures or etc, when in this thread alone you have proved they are different. Trust me, I do not have an adjustable prop valve in my Rubi, and I do have 4 wheel disc brakes. FYI a prop valve only works in a panic stop situation, not slowing for a stop sign.

Because you are 4 years late to the game for something already proven.

And if you were paying attention, you would know I am running a hydroboost, not exactly stock, hence the need for the adjustable proportioning valve.

[waynehartwig]

And if you were paying attention, you would know I am running a hydroboost, not exactly stock, hence the need for the adjustable proportioning valve.

Unfortunately, I have been paying attention....:zip:

[wwprice881]

Hello I just put a DANA 44 Locker system from a 2004 Rubicon into my 2006 Wrangler.
When you mentioned thet the wires coming back from the lockers to you dash where the 12v LED's are, does this have to be connected to make the lockers actually work?

I am in the process of wiring this and only one of my two pump is working. So I have just bought a new dual pump to replace the old one that has one no working.

Right now I am in the process of wiring the Lockers and any help would be appreciated. I do have questions on how you wired you relays. Did you put in dual relays? I did

Hope t hear from you

[JpPassenger]

Hello I just put a DANA 44 Locker system from a 2004 Rubicon into my 2006 Wrangler.
When you mentioned thet the wires coming back from the lockers to you dash where the 12v LED's are, does this have to be connected to make the lockers actually work?

I am in the process of wiring this and only one of my two pump is working. So I have just bought a new dual pump to replace the old one that has one no working.

Right now I am in the process of wiring the Lockers and any help would be appreciated. I do have questions on how you wired you relays. Did you put in dual relays? I did

Hope t hear from you

The sense leads coming from the axle itself don't need to be connected. They only provide positive feedback that the locker is engaged.

I did not notice any relays in the factory manual schematic. Not that they don't exist, but I did not notice them.

I did not use relays. Just 20A switches.

Good luck,
Greg