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comanche dana 35 to dana 44 swap

'88 sportrucker

NAXJA Forum User
Location
Douglas City, CA
I have an '88 comanche 4X2 sportruck that's all stock with a 2.5 L fourbanger and a 4 speed manual tranny. I just bought her a few weeks ago even though the registration was 2 1/2 years overdue, she hadn't been driven at least that long, the steering had 6" of play, the brakes were marginal, the rear end was noisy, the tires were shot and she hadn't been smog tested for years. Kinda scary, huh? Well I'm practically fearless, I bought her anyway and now I've got everything squared away including smog certification, and license registration. One problem remains, the noisy rear end. I had the axles pulled and the bearings and seals replaced. No Joy, the differential still sounds very unhappy with some sort of scraping, grinding noise that's most noticeable around 20-25 mph. What to do? I found a dana 44 rear axle in a junkyard mounted on a 1988 comanche long bed with 225,000+ miles on the odometer. The junkyard guy says it's a direct bolt-on. (my comanche has a short bed) Question #1--- is it or ain't it a bolt-on? Will the different drive shafts, yokes, whatever, present any probs? Question #2--- What about gear ratios? the junkyard guy says it's 3.07 on the d44. I don't know what mine is, the ratio tag is missing, the axle has a build date of 4-16-8 2A and a Bill of material # of 605324 5XA stamped on the axle. Can anyone decypher that for me? Could a large change in ratios affect what my small 2.5 liters can handle to an unacceptable degree? The Junkyard guy wants $700 for that d44 and my pockets aren't very deep. I hear the D44 is a lot more robust than a D35 (which mine is dying at 187K) so I'm wondering how much more robust. Should I rebuild the D35 or go for a swap? Any info or advice would be much appreciated.
 
Your MJ came with 4:10 gears and going down to 3:07's would suck big time

As for the axle it is a quick direct bolt in, but dont forget to get the ubolts and spring plates also.

The d44 is a very nice axle but look around they can usually be picked up for much less than 700.00, I got mine for 250.00, can be found here on the site for around 300.00. It is a great upgrade

the only difference might be drive shaft length, but if you need one I have one sitting here in the DS pile you just pay shipping.
 
Do some searching and reading on rear axles. The Dana 35 is Ok for moderate wheeling and 31's. The 8.25 is a bit stronger. The Dana 44 is stronger still, but do you need it yet? (tire size, wheeling style). D44's for sale here on NAXJA are $350-375 + about $125.00 for shipping. At the local pick-and-pull auto parts all axles are $85.00. The local junkyards get from $150.00 to 350.00 for an axle already pulled. Your gears are most likely 4.10's. That would be too much of a difference between the 3.07's in the 44. All years and types of XJ axles are a direct swap into another XJ but you will need to be aware of spring pad locations. Pickups (I think) are spring under the axle, XJ springs are on top of the axle. Not too hard to change spring pad locations as needed. Some small differences in drive shaft lengths. Price the exact cost of parts (new or used?) you will need for either a fix or a swap. Add in the cost of a new-used axle. Search the for sale page for prices.
Ideas
-get a used 8.25 axle from a NAXJA member
-get gears and/or a locker from a NAXJA member and fix what you have or put them into your new 8.25


Gearing

3.07 - used with 4.0L engine / manual transmission
3.31 - only available on older (pre87?) 2 door XJs with "Fuel Economy" package
3.55 - used with 4.0L engine / automatic transmission
3.73 - found in some XJs with the towing package
4.10 - used with 2.5L engine usually, and older XJs with the "Off-Highway Vehicle" package.
4.56 - rare but can be found on some older (~ 89 ~) models with 2.5L engine and auto transmission
 
Last edited:
Tim_MN said:
Do some searching and reading on rear axles. The Dana 35 is Ok for moderate wheeling and 31's. The 8.25 is a bit stronger. The Dana 44 is stronger still, but do you need it yet? (tire size, wheeling style). D44's for sale here on NAXJA are $350-375 + about $125.00 for shipping. At the local pick-and-pull auto parts all axles are $85.00. The local junkyards get from $150.00 to 350.00 for an axle already pulled. Your gears are most likely 4.10's. That would be too much of a difference between the 3.07's in the 44. All years and types of XJ axles are a direct swap into another XJ but you will nned to be aware of spring pad locations. Pickups are spring under the axle, XJ springs are on top of the axle. Not too hard to change as needed. Some small differences in drive shaft lengths. Price the exact cost of parts (new or used?) you will need for either a fix or a swap. Add in the cost of a new-used axle. Search the for sale page for prices.
Ideas
-get a used 8.25 axle from a NAXJA member
-get gears and/or a locker from a NAXJA member and fix what you have or put them into your new 8.25


Gearing

3.07 - used with 4.0L engine / manual transmission
3.31 - only available on older (pre87?) 2 door XJs with "Fuel Economy" package
3.55 - used with 4.0L engine / automatic transmission
3.73 - found in some XJs with the towing package
4.10 - used with 2.5L engine usually, and older XJs with the "Off-Highway Vehicle" package.
4.56 - rare but can be found on some older (~ 89 ~) models with 2.5L engine and auto transmission

He has an MJ not an XJ the axles are a tad different.

Spring under VS spring over and MJ's springs are not spaces as far apart.
 
Gotta disagree with XJnation here -- the 2.5L 4-speeds did NOT come with 4.10 gears. I have a twin to your truck sitting in my yard. 1988 SporTruck, 2.5L, 4-speed. The axle ratio is 3.54. They did that because of the lack of an overdrive gear.

Yes, the Dana 44 from a longbed will bolt in with no mods. The D44 pinion is about 5/8" longer, so you should check after it's installed to be sure when the suspension compresses that the front yoke doesn't bottom out on the tranny output shaft. Worst case would be you might have to take the driveshaft to a shop and have the length trimmed.

If the D44 came from a 4.0L with 5-speed, then it is a 3.07 and you probably won't be very happy with it. You can certainly dribve it like that, but unless you live in very flat terrain you'll be using 3rd gear a lot.

<EDIT>BTW, does your truck still have the little rod/bellcrank running up from the differential to a lever on the underside of the bed? That's a load-sensing proportioning valve for the rear brakes. If you still have it, be sure you remove the bracket thingie from the old diff and install it on the new one. Also be sure the arm on the valve stays oriented the same. If you change it, you'll have strange brake behavior.
 
Last edited:
Eagle said:
Gotta disagree with XJnation here -- the 2.5L 4-speeds did NOT come with 4.10 gears. I have a twin to your truck sitting in my yard. 1988 SporTruck, 2.5L, 4-speed. The axle ratio is 3.54. They did that because of the lack of an overdrive gear.

Yes, the Dana 44 from a longbed will bolt in with no mods. The D44 pinion is about 5/8" longer, so you should check after it's installed to be sure when the suspension compresses that the front yoke doesn't bottom out on the tranny output shaft. Worst case would be you might have to take the driveshaft to a shop and have the length trimmed.

If the D44 came from a 4.0L with 5-speed, then it is a 3.07 and you probably won't be very happy with it. You can certainly dribve it like that, but unless you live in very flat terrain you'll be using 3rd gear a lot.

<EDIT>BTW, does your truck still have the little rod/bellcrank running up from the differential to a lever on the underside of the bed? That's a load-sensing proportioning valve for the rear brakes. If you still have it, be sure you remove the bracket thingie from the old diff and install it on the new one. Also be sure the arm on the valve stays oriented the same. If you change it, you'll have strange brake behavior.

I hve an 89 and a 88 2.5 4 speed and both HAVE 4:10's
 
xjnation said:
I hve an 89 and a 88 2.5 4 speed and both HAVE 4:10's
:gag:
It's a Jeep thing -- I don't understand.
 
Eagle said:
:gag:
It's a Jeep thing -- I don't understand.


LOL you can count on jeep to not keep keep things simple.

jack it up put in neutral mark a tire straight up with chaulk. rotate the tire and see how many times the pinion yoke goes around. That will give you a good guess on the ratio. for 4:10's the pinion yoke should rotate 4 times to one tire rotation for 3:54 one for 3.5 pinion rotations...etc
 
xjnation, tim, eagle, Many thanks for the info, it helps a lot. I'll be sorting out my options. One thing for sure, when you jump into the jeep world you had best stay on your toes. These jeep folks are real mod-happy and as the guy said, "like a box of chocolates, you never know what yer gonna get" See Ya
PS: Come to think of it , this mod fever must be contagious. I no sooner arrive on the scene than I start considering modifying the rear end. Whoa!
 
xjnation said:
LOL you can count on jeep to not keep keep things simple.

jack it up put in neutral mark a tire straight up with chaulk. rotate the tire and see how many times the pinion yoke goes around. That will give you a good guess on the ratio. for 4:10's the pinion yoke should rotate 4 times to one tire rotation for 3:54 one for 3.5 pinion rotations...etc
First thing I did when I brought it home.

3.54
 
I found another Dana 44 mounted in the rear of an '87 Cherokee 4X4. The asking price is $350 which I guess is reasonable. The problem here is it ain't a direct bolt-in. So how big a deal is modifying it from spring-over mounting to my comanche's spring under? What kind of tolerances etc. are required? My experience working on suspensions is limited to changing a shock from time to time, beyond that I know only just enough to be dangerous. This D44 has a tag on the rear driver's side of the housing embossed with the numbers 8953005003 and below that 3 54 46-13. I assume the 3 54 would be, I mean "could be" the gear ratio. As to the rest? anyone have a clue? Is there any way to compensate for some difference in drive shaft length without modifying the shaft itself? That could cost big bucks which I can't afford. Also, I have the load-sensing proportioning valve installed. I understand that it increases the braking force applied to the rear wheels as the cargo bed is depressed by a load. Is this done in a linear fashion from the git-go or does it kick in after 2 or 300 or whatever lbs are loaded? How do you calibrate it? It seems to me that you could be locking up the rear wheels if your adjustment is too far off. Can it be safely by-passed? I don't plan on carrying any big loads and the tongue weight of my 12' aluminum fishing boat won't exceed 200 lbs max. Need help, fishing season is here!
 
[QUOTE='88 sportrucker]I found another Dana 44 mounted in the rear of an '87 Cherokee 4X4. The asking price is $350 which I guess is reasonable. The problem here is it ain't a direct bolt-in. So how big a deal is modifying it from spring-over mounting to my comanche's spring under? What kind of tolerances etc. are required? My experience working on suspensions is limited to changing a shock from time to time, beyond that I know only just enough to be dangerous. This D44 has a tag on the rear driver's side of the housing embossed with the numbers 8953005003 and below that 3 54 46-13.[/QUOTE]Assuming they're still good, the D35 e-brake cables will work. The softline going to the brake tee should fit as well or use an aftermarket one.

You need to remove the XJ springpads and weld in some new ones. The old ones can theoretically be reused or you can get new ones from M.O.R.E. or RE and I believe JKS also stocks them.

The 46 13 indicates 3.54 ratio, but open it up and look; a lot of people put the old tag back on for some reason after regearing.

The difference in length on the driveshaft is negligible; use your old one.

Can't help you on the rest - good luck.
 
Look on the ring gear for a long series of numbers indicating the part number, lot, manufacturer, etc. At the end of that series, there should be a pair of two-digit numbers indicating the ring and pinion tooth counts. Example: My D44 r+p has 46 13 at the end.
46 = Ring gear teeth
13 = Pinion teeth
46/13=3.54
 
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