D44 disc conversion

[ftpiercecracker1]

Been sitting on D44 for a while now and finally got around to putting it in.

 

Currently have a chry 8.25 which I also did a disc swap on to great success and would also like to swap to discs on the 44.

 

After much research, both on this site and elsewhere it seems there are two budget oriented options.

 

 

95, or similar, Crown Victoria/Marque

https://naxja.org/forum/showthread.php?t=1045256

 

 

Or

 

 

Ford explorer 

https://comancheclub.com/topic/57351-dana-44-disc-brake-conversion/

 

 

I don't like the Explorer because of how little material is left after hogging out the holes on the backing plate.

 

The Crown Vic does not need this but instead needs the center hole slightly enlarged. After which there is still ample amounts of material left.

 

 

For those who have done this how was your experience? Any unforeseen complications? I'm using wheel spacers so longer studs shouldn't be an issue. I have already ordered the TeraFlex spacers. Now I just need to make a decision as to which option to go with for the rest of the parts. I will be sourcing everything I can from the JY.

[ghetdjc320]

Is this going on an mj 44 or a later model 44?

[ftpiercecracker1]

8 hours ago, ghetdjc320 said:

Is this going on an mj 44 or a later model 44?

 

 MJ 44

[agamble]

I went with the Ford 8.8 backing plates and calipers paired with ZJ rear disc rotors when I did this conversion. Have not had any issues. 
 

I went with the setup I mentioned as all I could read up on the conversion showed  Ford explorer rear discs read to be the best for this conversion as the spacing on the backing plates is closest to the D44.

-  95 - 01' Ford 8.8 rear discs backing plate has a 2" x 3 9/16" bolt pattern

-  86 - 90 MJ/XJ D44 has a 2" x 3 11/32" bolt pattern

This gives a horizontal difference of 7/32" between the two backing plates. The explorer backing plate need the holes to be inwardly elongated 7/32" for them to bolt onto the D44 housing.  A dremel with a carbide bit made quick work on elongating the Ford 8.8 backing plates. Remove about 1/8"  inward side of each hole. I used the retaining plate to measure when I had removed enough material. 

 

When selecting rotors I had read of some using explorer rotors and others going with ZJ rotors. The difference between the two is practially negligible. I read of some people getting some brake pad drag when using the Ford 8.8 rotor. But the main issue with using Ford 8.8 rotors is the center hole. The D44 axle shaft will not fit through the center hole without widening it. About .015" needs to be removed from the inner surface, a flapper wheel could probably take care of this. I went with the ZJ rear rotors due to the two issues that I read about the Ford 8.8 rotors I went with the ZJ rotors. 

 

[ftpiercecracker1]

1 hour ago, agamble said:

I went with the Ford 8.8 backing plates and calipers paired with ZJ rear disc rotors when I did this conversion. Have not had any issues. 
 

I went with the setup I mentioned as all I could read up on the conversion showed  Ford explorer rear discs read to be the best for this conversion as the spacing on the backing plates is closest to the D44.

-  95 - 01' Ford 8.8 rear discs backing plate has a 2" x 3 9/16" bolt pattern

-  86 - 90 MJ/XJ D44 has a 2" x 3 11/32" bolt pattern

This gives a horizontal difference of 7/32" between the two backing plates. The explorer backing plate need the holes to be inwardly elongated 7/32" for them to bolt onto the D44 housing.  A dremel with a carbide bit made quick work on elongating the Ford 8.8 backing plates. Remove about 1/8"  inward side of each hole. I used the retaining plate to measure when I had removed enough material. 

 

When selecting rotors I had read of some using explorer rotors and others going with ZJ rotors. The difference between the two is practially negligible. I read of some people getting some brake pad drag when using the Ford 8.8 rotor. But the main issue with using Ford 8.8 rotors is the center hole. The D44 axle shaft will not fit through the center hole without widening it. About .015" needs to be removed from the inner surface, a flapper wheel could probably take care of this. I went with the ZJ rear rotors due to the two issues that I read about the Ford 8.8 rotors I went with the ZJ rotors. 

 

 

 

Thanks? This is just a copy and paste from the threads I've already read, the source what information I do have and what i have linked in my initial post.

 

Did you do this conversion?

 

The elongated holes in the Explorer backing plates leave very little material between the inner hole for the shaft and the mounting holes. 

 

But if that lost material is inconsequential and the overall performance and ease of install is greater than the Crown Vic, I'll go with the Explorer option. 

 

I was hoping someone could give testimony as to their direct hands-on experience with using one or the other. Or if there is some other easily sourced option I haven't found yet.

[agamble]

Haha, the copy paste you’re referring to in my response is indeed copied from my thread(s). I have it on my build thread and I put it in the DIY section of this forum here as well. So,  indirectly this was me saying I’ve personally done the conversion and currently run the setup on my Comanche. Why reinvent the wheel so to speak. I’ve already provided my first hand insight.
 

If you elongate only one side, yes it leaves very little material. But if you take material from both sides when you open the holes there still is substantial material. 

[ftpiercecracker1]

3 hours ago, agamble said:

Haha, the copy paste you’re referring to in my response is indeed copied from my thread(s). I have it on my build thread and I put it in the DIY section of this forum here as well. So,  indirectly this was me saying I’ve personally done the conversion and currently run the setup on my Comanche. Why reinvent the wheel so to speak. I’ve already provided my first hand insight.
 

If you elongate only one side, yes it leaves very little material. But if you take material from both sides when you open the holes there still is substantial material. 

 

 

Gotcha, thanks for the clarification. I didn't bother to look at the author.

 

I'm going to re-read your thread. If I have any questions I know who to ask now. 👍

 

I was leaning towards the Explorer just for the sake of symmetry anyway.

[ftpiercecracker1]

Been looking for a bearing and seal kit for the D44 and finally found one that specifically says for MJ/XJ Dana 44.

 

https://www.ebay.com/itm/152948634321

 

Ordered. Should be here Saturday. Hopefully everything is as it shows.

[ftpiercecracker1]

Resurrecting this thread.

 

Trying to pin down a backing plate and spacer issue.

 

Ordered a set of ring/spacers from someplace I can't remember. Ring OD fit the backing plate ID well enough. The "length", if you imagine this ring as a extremely short pipe, is fine. Another way to look at it is the height of this as a short cylinder.

 

The issue is the wall thickness or the ID of the ring. It just barely catches the outside edge of the lip seal.

 

Several month later I broke down and ordered a set directly from TeraFlex as is suggested in agamble's write up. PN 86261

 

 

The issue with the TeraFlex rings is their OD is far smaller than the ID of the backing plate.

 

It was my understanding that when the seal and bearing are fully seated the seal should be essentially flush with the axle tube flange. This means the smaller teraflex ring would be floating in midair. Help tightly up against the seal by only the pressure of the retainer plate. 

 

The depth from the face of axle tube flange to the shoulder where the bearing will rest is .9 inches.

 

The thickness of the bearing and seal is 1.1 inches.

 

Meaning, even when fully seated the seal will sit slightly proud of the flange face. 

 

It seems to me I need a ring/spacer that has the OD of the backing plates ID and the ID of the seal.

 

Also, am I correct about the seal sitting flush with the flange face when fully seated?

 

 

 

 

 

TeraFlex ring does not fit the ID of the  plate.

 

 

Mystery ring fits backing plate, but the rings ID just barely has contact with the lip seal OD.

 

 

 

Axle tube depth to shoulder. 

.95 inches

 

 

 

 

 

Lip seal and bearing thickness.

1.1 inches

 

 

 

 

 

[ftpiercecracker1]

Yes, I have the same spacers.

 

You bought backing plates directly from TeraFlex?

 

I could not get in contact with teraflex as there "contact us" page has been corrupted. I searched for a number and never could find one. Even tried contacting one of their dealers.

 

I am using junkyard Ford explorer backing plates as. I'm basically following agambles writeup.

 

 

 

 

If it comes down to it I can have my brother custom make them. I was just hoping i wouldn't have to bother him.

 

 

 

[AZJeff]

I put a complete Teraflex kit on my D44, and although its' been a few years, I seem to remember the spacers that Teraflex provided were of an incorrect dimension.  I cannot remember for sure, but I seem to think they were too thick.   

 

I am going to go check my records to see what instructions I gave the machine shop that altered them for me.

[yungupgrade]

https://teraflex.com/1991-06-dana-chrysler-rear-disc-brake-conversion-kit.html

 

From a quick google search. Maybe this is a knockoff? Either way almost 800 for a conversion kit seems like a lot

[87MJTIM]

1 hour ago, yungupgrade said:

https://teraflex.com/1991-06-dana-chrysler-rear-disc-brake-conversion-kit.html

 

From a quick google search. Maybe this is a knockoff? Either way almost 800 for a conversion kit seems like a lot

The same conversion kit is available on Morris4x4 for $40 less

 

https://www.morris4x4center.com/teraflex-rear-disc-brake-kit-jeep-late-model-bearing-pocket-tf-4354420.html

[87MJTIM]

20 minutes ago, saveevryjp1998 said:

So the more I thought about it, the more I realized I had these sets before COVID and the better info on the subject was yet deeper in the archives here. More/better info on disc backing plates found mixed in here. I think I paid around $225-250 a set of backing plates shipped to my door at the time I ordered.

 

Those brakes look pretty familiar... where have seen those before?

[Airborne Janitor]

I converted to discs on my XJ's D44 many years ago, before any "kits" were available. I converted them over with ZJ parts and backing plates. I "think" I used TJ Rubicon backing plates. The problem was that the "spacer" on the backing plate was slightly too thick, causing too much compression on the outer seals and causing them to leak. I ended up having to machine "maybe" .010 off the spacer to where they wouldn't crush the seals. This was almost 20 years ago, wish I had better details.

[yungupgrade]

19 minutes ago, Airborne Janitor said:

I converted to discs on my XJ's D44 many years ago, before any "kits" were available. I converted them over with ZJ parts and backing plates. I "think" I used TJ Rubicon backing plates. The problem was that the "spacer" on the backing plate was slightly too thick, causing too much compression on the outer seals and causing them to leak. I ended up having to machine "maybe" .010 off the spacer to where they wouldn't crush the seals. This was almost 20 years ago, wish I had better details.

Looking to do this mod myself but I can't really justify almost 800 for a brake conversion kit, probably will have to go the junkyard parts route

[HeavyMetal]

Does everyone find that the OEM prop valve setup works well for rear discs?

[Airborne Janitor]

7 hours ago, HeavyMetal said:

Does everyone find that the OEM prop valve setup works well for rear discs?

 

When I converted my XJ I also swapped in a ZJ prop valve (52009061AB)

[ftpiercecracker1]

So me and my brother (the machinist) final looked at the axle the other day, took some measurements, did some hemin and hawin. 

 

Rather than make completely custom spacers, I'm just gonna use the teraflex spacers and tack them onto the retainer plate and let it ride.

 

An interesting bit of information.

 

The overall thickness of the bearing, seal and spacer will result in .020 of crush once the retainer plate is fully torqued down.

 

From what we can tell the face of the axle seal never sits completely flush with the face of the axle flange. 

 

Hoping to get the axle put together this coming week.

 

I'll reply here with the result.