|Budget Axle Upgrades for Later Jeeps||Short Cuts|
By: Paul Weitlauf - 8/2000
Homebrewed XJ Cherokee Axle Upgrades
Let me begin by saying the front axle portion of this swap is probably not for everyone - especially if you have a leaf-sprung YJ Wrangler. A front & rear Dana 44 swap would be simpler and probably cheaper for the YJ owner. If you don't have access to free/cheap parts, it may not even be cost effective for the XJ Cherokee, MJ Comanche or TJ Wrangler owner as you can probably swap in a Dana 44 using aftermarket brackets from someone such as Rubicon Express. With that said, let's get into the meat of the article and then you can decide for yourself if any this swap is for you.
|Paul's XJ before the axle modifications.|
|Dana 44 rear end from a Scout II installed in the XJ.|
|The Scout Dana 30 knuckles freed from their housing.|
|The next step was to strip down the XJ front axle and remove it from the rig for easier access to cut off the old yokes and to clean it up a bit.|
|The stock XJ Front axle removed from the truck.|
|Randy, cutting the XJ's RH knuckle yoke off with a plasma cutter.|
|Pressing the tube out of the Scout yokes.|
|Brian, dressing up the tubes in preparation for the Scout yokes.|
|Brian, checking the angles with a protractor before welding the yokes on.|
|Randy, welding the yokes on.|
|RH side with the "new" yoke and gusseted lower control arm mount.|
|LH side yoke, LCA mount and boxed in spring perch.|
|Here you can see the results of what happens if you try to use the stock XJ inner axle with a Scout Dana 30 stub axle. As you can see, the U-joint is positioned in the knuckle's spindle bore, making spindle installation impossible.|
|Here's the left side with a Scout Dana 30 right hand axle shaft in place. This is where the U-joint is supposed to be.|
|Scout Dana 44 knuckle and stub axle.|
|Here you can see the installed Scout Dana 44 spindle, dust shield and caliper bracket, as well as the Chevy tie rod end and Wrangler drag link. Gone forever is the XJ's original inverted "Y" steering linkage.|
|The finished Jeep.|
Here is what I started with before my conversion: 1986 Jeep Cherokee (XJ) Laredo, 4 door, 2.8L V6, A-904 automatic with shift kit, NP207 Command-Trac transfer case, stock 4.10/4.11 geared Dana 30 front and Dana 35 rear with Lock-Rights in both. Lift is a 6" mix-n-match bargain hunter's lift (FRONT: 4.5" Rubicon Express coils, Tera 1.75" spacers, an extra coil spring isolator, old-style Tomken arms and Rancho RS9010 shocks with homemade stud eliminator brackets. REAR: Rancho 1.5" add-a-leaf [long style], 3" lift blocks from a mid '70's Dodge W-200, MJ rear shackles [1" longer than XJ units for " of lift] and Rancho RS9010 shocks.) Fenders trimmed front and rear to clear 33x12.50 Super Swampers on OEM 10-spoke 15x7 Laredo alloy rims with 5.25" backspacing with the stock 5 lug, 4.5" bolt circle. A Warn 8274 winch is mounted to a homemade 2x6 steel bumper. Track width was the stock 58" front and rear.
Here is what I changed during this conversion: The rear axle was replaced with a 1972 IH Scout II Dana 44 with 4.55:1 gears and a Detroit EZ-Locker. Front axle gearing was changed to a "matching" 4.56:1 and was modified to accept Dana 44 (or Dana 30) full-floating knuckles-out to match the rear axle's wheel bolt pattern, get freewheeling hubs and bigger front disc brakes. Scout II parts were used for this - knuckle yokes from a 1972 IH Scout II Dana 30, knuckles-out from a 1980 IH Scout II Dana 44. Wheels were changed to 15x10 white spoke wheels with 3" backspacing and the now necessary 5 lug, 5.5" bolt circle. The tires were removed from the 15x7 alloys and mounted on the 15x10's. Front track width is now 60.5" and the rear is 63.5".
I had been contemplating the feasibility of this kind of swap for a couple of years. What moved me into action was the failure of my XJ's Dana 35. I chose to install a '72 Scout Dana 44 in the rear of my XJ, which was a fairly straightforward swap, so I won't go into a lot of detail on that part of the conversion. The Scout axle is just slightly narrower than the XJ unit (59" vs. 61"), but when you consider the different offset used with the 5 lug, 5.5" bolt circle wheels, it comes out wider. How much wider will depend on the backspacing of rims you select. The Scout rear axle only required installing new spring perches and shock mounts. In my case, driveshaft length was not altered. I am running a stock rear driveshaft, so the Dana 44's extra " or so of pinion length just pushed my slip yoke closer to its factory original location.
The second photo down on the right is of the Scout II rear being installed. Note that the shock mounts are not yet installed. The XJ's brake lines & E-brake cables hooked right up with no troubles, except a mount tab had to be fabricated for the rear brake "T" block because the Scout wears it's "T" block on the right side and the XJ has it on the left. The hole in the axle tube for the Scout's "T" block was used to mount the XJ's brake line guard. The shock mounts were removed from the XJ axle and ground a little to match the larger Dana 44 axle tube and then welded in the stock position. It would have been a little better to make new mounts and mount them higher, but I didn't want to purchase new rear shocks.
Other viable rear axle options would be a Dana 44 from an '87-'89 XJ, which would not require any change in wheels and bolts right in. A Dana 44 from a MJ Comanche is the same width and wheel bolt pattern as the XJ version, but due to differences in spring and shock locations, it will not bolt in. Likewise with the rare '86 MJ heavy-duty AMC Model 20. Either MJ axle will require similar installation work to other options, like the heavy-duty AMC Model 20 found in'80-'86 SJ Wagoneers and '80-'83 narrow track "flareless" SJ Cherokees, or the '86-'92 SJ Wagoneer Dana 44. Both of the SJ axles sport a 6 lug, 5.5" bolt circle, so with one of these axles, you'll face a similar decision on what to do about the front axle.
I chose the Scout II axle for several reasons. First, XJ & MJ Dana 44's command a high price from local wrecking yards and finding one through private parties parting out rigs is next to impossible, since this wasn't a high volume option and it seems not many XJ's are found in the local classifieds being parted out anyway. Secondly, the Scout II Dana 44 uses symmetrical axle shafts, meaning the left and right shafts are interchangeable. This means only one spare needs to be carried on those trails where you may expect to break something. The difference in the pinion offset is only about 1", so driveshaft angularity is not a concern. The earlier 1970-1974 Scout II axle also has 11x1.75 inch brakes versus the stock Dana 35's 10x1.75 inch brakes (1975-1980 Scouts have even larger 11x2 inch brakes). The most important reason I chose the Scout rear axle is because I had one in my stockpile of parts.
To get the front axle to have a matching bolt pattern requires some changes up front. You can choose to upgrade the whole axle to a Dana 44, but since there is nothing that directly bolts in, this option requires installing all the brackets for the XJ's suspension. Tests have shown the reverse-cut Dana 30 to have a ring & pinion strength equal to a standard-cut Dana 44 in a front axle application because they drive their gears on the "drive" side instead of the "coast" side of the teeth. For this reason, I decided to retain the Dana 30 and save a little in the ground clearance department as well as in the wallet. To change the front axle's bolt pattern you can choose to go with a Warn conversion kit that will do this job and retain your stock inner axle shafts (or upgrade to Warn's alloy shafts with the Dana 44 sized "297" U-joints). Going this route will cost $700-$800, plus the cost of modified CJ brake rotors... and that doesn't include the alloy inner axle shafts. Being somewhat of a penny-pincher and having a pretty good stash of spare parts sitting around, I decided to go my own route.
The XJ and all new Jeep designs since then use a different style knuckle yoke than the full-floating style axles. To get what I wanted meant the stock knuckle yokes would have to come off and be replaced with the style used on the full floating axles. Breaking out the dial caliper and measuring a few Dana 44's, I found their axle tubes have a larger 2.75" outside diameter versus the 2.50" of the stock Dana 30, so their yokes wouldn't work. Careful measurement showed the Scout Dana 30 had tubes exactly the same diameter as those on the XJ. I didn't have ready access to an Early Bronco or CJ's Dana 30, but my guess is they are probably the same as well. So the torch was fired up and the knuckle yokes were liberated from a Scout's Dana 30. (If you have to buy these, they can probably be acquired real cheap, since most Scout owners could care less about these standard cut Dana 30s!)
Since this is a rather delicate process - you don't want to damage the axle tubes since you are not changing their length - I employed the services of Randy's Off Road Connection in Marysville, WA to remove the XJ's yokes with a plasma cutter and weld the Scout yokes in place. They also removed the little bit of axle tubes from the Scout's knuckle yokes, since these had just been torched off the donor at a handy spot. (As a side note, Randy told me it would have been easier for him if I had just brought in the whole Scout Dana 30 housing.)
Since I don't run the front sway bar at all anymore, I had the sway bar brackets removed from the XJ housing. I also took this opportunity to beef up the lower control arm mounts and box in the LH spring mount since it would no longer be getting any support from the sway bar mount. The RH side is already pretty strong since it has the attachments for the steering stabilizer and track bar.
This conversion requires new inner axle shafts because the stock ones will now be 1 5/8" too long due to the difference in knuckle yoke designs. Due to the neck-down in the shafts outboard of the splines, you can't shorten the stock axle shafts. I discovered the Scout Dana 30's short side (right hand) inner axle works perfectly for the XJ's short side (left hand). I still needed something for the long side, but I was unable to find any stock Dana 30 shaft that would fit or could even be modified to fit.
Much to my dismay, I learned that Warn no longer offers custom length axles, so I couldn't go to them... Well, I could have used their XJ/YJ/TJ alloy inner shafts and narrowed them, but that would have added $100 or so on top of the price of their shafts. That wasn't very appealing, especially when I found I could get custom shafts built from Moser Engineering at a lower cost than just buying Warn's shafts. Moser offered stock strength shafts with stock "260" series joints - in which case I would have only had to buy a long side shaft. They also offered a heavy-duty alloy shaft with the larger and stronger "297" series joints for a few dollars more, so I decided to go with those, since one of the goals behind this swap was to build a stronger front end.
There is one other issue that you must address with this conversion if you are dealing with a disconnect type housing and that is the right hand axle's seal. Disconnect equipped housings seal the large outer half of the axle shaft on the outboard side of the disconnect housing. The disconnect axle diameter at the seal is 1.63". One-piece (non-disconnect style) axles seal the shaft next to the carrier, just like the left side shaft. One-piece axles retain a smaller outside diameter (about 1.2") almost all the way out to the U-joint yoke. In 1987 and up disconnect models, you can use a standard Dana 30 axle seal (like the one used on the left side shaft) in the stock disconnect seal location. Just be sure your new one-piece axle shaft has a 1.20" polished diameter at this location. On 1986 and earlier XJ Cherokees and MJ Comanches like mine, the seal used in the disconnect has a larger outside diameter, so the standard non-disconnect type seal is too small to fit in the disconnect housing. Warn comes to the rescue here by offering a special seal that you install in the "normal" (next to the carrier, non-disconnect style) position. They make this seal for their conversion kits, but it happens to work just fine for this swap as well.
From this point you have several options as to what you use for knuckles, brakes and hubs. You can use parts from just about any Dana 30 or Dana 44 full floating knuckle or assortment you choose. You may need to re-think your steering set-up with some knuckles though. If you choose to run the "297" series U-joints, you will need a stub axle that uses this joint (most Dana 44's use this joint, but some applications use "260" series). If you choose to stay with a "260" series joint, Scout, Early Bronco or CJ Dana 30 stubs and some Dana 44's (Early Bronco and some 80's SJ Jeeps) will have the appropriate stub axle. Again, Scout parts were chosen because they were collecting dust on a shelf, but since Scout Dana 30's use drum brakes and the "260" U-joints, Scout Dana 44 knuckles, stub axles and disc brakes were used.
The Scout knuckles required a change to the steering since Scouts use bigger tie rod ends than the Cherokee. I also didn't want to use the Scout location for the drag link because too much turning radius would be lost due to the length of the Scout's steering arms. (Some is lost anyway since even in the closer location, the arm is longer than what the Cherokee came with.) I couldn't find a tie rod end in the Scout's size that would accept a tie rod end for a drag link, but I learned that 1981-1987 Chevy K-5 Blazers, K-10 & K-20 4WD pickups (or GMC K-5, K-1500 & K-2500) have a left side tie rod end that is designed to accept a tapered stud for the steering stabilizer. The end itself is larger though, so the Scout knuckles were taper reamed to the larger Chevy size. The Chevy left-hand end was used on the right side and a right-hand Chevy end was used on the left. The tapered bore for the stabilizer stud is the same size as the Cherokee & Wrangler tie rod ends and I was able to use a stock drag link from a 1987-1990 YJ Wrangler. The tie rod itself is a shortened tie rod from the same 1981-1987 Chevy K series truck. Optionally, tie rod stock is available from many racecar outfitters or 4x4 fabrication shops.
Test driving after the conversion showed the stock master cylinder does not provide enough volume for the larger Scout calipers and rear wheel cylinders. With no air in the system, it took an extra pump of the brake pedal to keep it from hitting the floor. I recommend the master cylinder swap by Ron Hollatz that is also found on Jeepwire. It was written for the YJ owner, but it applies to the XJ as well.
One last thing I discovered was that there was nearly a problem with my rim and steering choice. There is minimal clearance between the tie rod end and edge of the rim. The clearance is small enough to prevent the use of standard wheel weights on the inside bead of the rim. Aluminum wheels of this size may not work with this setup, so take this into consideration as well.
A very special thanks goes out to Randy & Brian at Randy's Off Road Connection for the knuckle swap, control arm & spring perch reinforcement and set-up of ring and pinions in both axles. And also allowing me to hang out in the shop and shoot pictures while they worked.