There has been talk recently of swapping a d35c for a d44a, and a write-up was requested by a few. If anyone catches mistakes or think something is wrong, please speak up. I have personally never done this. Also, someone who has please comment on whether you will need to use a driveshaft that was with a d44a, or if the stock d35c driveshaft will work.
This assumes the following:
1. The d44a you are swapping in is the same gearing as your front end (all d44a are 3.73 ratio from the factory. d30s in ZJs are 3.55 in in some I6 and 3.73 in the other I6s and all v8s.)
2. The d44a you are using is from a ZJ or if it from a WJ you have already modified/changed the coil buckets to accept the ZJ coil.
3. The brake lines on the d44a are in good condition and have the rubber line that runs from the tee on the axle to the hard line on the body attached. This can be extended using a rear brake line from a 78 ford f250 if my memory serves me correct. It should be 2” longer.
Reasons you would want to make the swap:
1. D44a is stronger than the d35c and can handle up to 33”+ tires stock.
2. D44a comes with disk brakes and you are doing a disk brake swap anyway, so want to upgrade at the same time for a comparable price.
3. You regearded your d30 front to 3.73 from 3.55 and instead of having new gears put in your d35c (100 for gears +2 00 for install) you opt to do the d44a swap.
1. On a level surface chock the front tires. Jack up the rear of the Jeep and place jack stand on the unibody directly in front of the lower control arm mounts.
2. Remove both rear tires.
3. Unbolt the top (body side) of the track bar. Head is a torx t55 and nut is a 18mm (need open end to hold nut as a box or socket will not fit due to bump stop cup)
4. Unbolt the bottom of the shocks. 15mm head, 18mm nut.
5. Unbolt sway bar links. 15mm nut (need deep socket or box/open wrench), 15mm bolt.
6. Using a floor jack on the center of the diff, or 2 stock bottle jacks with one in the center of each axle tube, lower the rear axle until the springs unseat.
7. Disconnect the driveshaft from the pinion yoke. 8mm bolt. Jeep in mind that if you have the stock slip yoke on the tcase the driveshaft is now free.
8. Disconnect the brake line hose at the hard line on the body using a line wrench(cant remember size sorry)
9. Disconnect parking brake cables from axle. (I’m unsure if the d35 with drum brakes has a parking brake setup that is the same as a d44a. consider this before swapping)
10. Unplug wheel speed sensor wires at body.
11. Unbolt coil spring retainer on bottom. 13mm
12. Remove coils.
13. Unbolt lower control arms at axle side. 21mm bolt, 21mm nut. (you may want to crack it loose while the jeep is still sitting on all 4 tires. They can be a bear if they are rusted at all and are usually very tight.
14. Unbolt upper control arms on axle side.
15. Axle is now free, slide out and admire your work!
16. To install d44a, reverse steps.
Note: The t55 track bar bolts are notorious for causing problems. The heads easily rust and cause the torx to strip. Feel free to replace them with grade 8 hex head bolts. I think they are size m12.
'98 ZJ on 37s and tons
'97 Cummins 2500
If you have 4.5"+ or so of lift the a stock d35 DS will work, but you will need to use a 1310-1330 hybrid ujoint.
I'm at 3" of lift and I had to shorten my d35 DS about 1.5" and use the hybrid ujoint
The parking brake cable from the d35 drum brake setup will work with the 44a. I just chose not to do it on my swap.
I just replaced a blown 35 to with another 35 but the bits I have to contribute should work regardless of your swap ingredients. Couple things:
The ABS disconnects are under the rear seat on the driver's side. There's a red plug and a black plug. Unplug them both push the grommets through the floor.
The upper control arm mount also is a torx (not a T-55) but my experience with them has taught me to ignore them and put a big set of Vice-grips on the head and put a ratchet on the back side nut rather than bother with the torx. That technique worked fine on both sides.
I managed to get the axle-side T-55 bolt to back out of the captured nut on the axle. First thing I took the plastic cover off the pocket the track bar sits inside as it doesn't seem to do anything anyway. Then I took a plumber's propane torch and got the bolt as hot as I could (front and backside), using a 1/2 inch socket wrench, I sat beside the driver's side wheel and lowered the axle as low as possible so I could get the ratchet head around the gas tank skid. I should mention, I absolutely destroyed the T-55 socket doing this. I had probably torqued it about 20 degrees when I was done. It did come out though. I looked for a suitable replacement bolt and couldn't find one at my local hardware store so I took the old bolt to my bench grinder and ground down 2 sides until I could snugly get a 1 inch open-end-wrench on it. Worked great.
The emergency brake assembly is a colossal pain in the arse. I think you should plan on changing the interior pads while you have the rotors off. Both my old broken axle and my junkyard axle, the parking brake pads and hardware were completely wasted. $40 for pads and hardware at Autozone.
I couldn't get the old e-brake cable off so I gave up and cut it off in sections with a bolt-cutter. Worked great and was easy.
One potential snag, the piece of hardware that connects the 2 e-brake cables to the 1 hand-brake cable was rusted into 1 giant block of crud making it impossible to back-off to adjust. I eventually ground the center pin out and replaced the long bolt that connects to the e-brake cables with a simple carriage bolt and nylock nut. I had to shave the top and bottom off the bolt head in the bench grinder and I put a small nut and bolt in place of the old riveted pin. $2 at Ace
A few parting thoughts to remember, the axle is heavy, really heavy and as soon as you put it down, it's gonna puke black gear oil all over everything which smells horrible. This whole process works a lot better if you can get someone to help you. Which is my last point, this takes a long time to do. I'm sure there are people who say "I did a rear end in 45 minutes with nothing more a set of rusty pliers in the dark and it was 45 below!" Yeah well, I didn't. I'm not a professional mechanic. I don't have air tools nor a lift. I have a $35 trolley jack I got a AZ and a pretty good set of Craftsman tools, that's it. I got a great helper most of today and it still took us about 10 solid hours to put the axle back in, hook everything up and bleed the brakes. Allow a good weekend for this procedure. That's it, keep it shiny side up.
I love sleep. My life has the tendency to fall apart when I'm awake, you know?
If the trans length is the same , you have no issue , so , if someone knows the trans length for the 42RE,44RE, 46RH and the 46RE , a better answer could be given . As for the t-cases , the only difference in length I know of is between the internal and external slip yokes on the 242 , external being .75ish longer .
So we are clear , yes , there is a different yoke on the 5.9's D44a , there would be no difference in the length's AFIK .
Im going to be rebuilding a D44a to swap in for my D35, glad i found this quick writeup.
I would like more info on brakes... when I pulled the 44a I cut the brake lines because the nuts were so seized, i would have needed an air tool and no way to get one accessible in the yard. I want to run new brake lines anyway. I'll be posting my own thread with input and progress of my build
Determine never to be idle. No person will have occasion to complain of the want of time who never loses any. It is wonderful how much may be done if we are always doing. - Thomas Jefferson
Not all V8 ZJ's have 3.73 gearing. I know it says they are all 3.73 geared, but that's 96-98's that are 3.73. 93-95 could be 3.55 or 3.73. This gets talked about every so often on threads as the FAQ being wrong, but I don't believe Jeff or any of the other Mod's have actually fixed it.