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Superior Axle's new axle Super Truss kit installed.

14K views 29 replies 11 participants last post by  4point 
#1 ·
Superior Axle’s new Dana 44 axle truss kit is installed!

Few things are ever strong enough right out of the factory and that includes the TJ version of our beloved Dana 44 rear axle. The Dana 44 is a fairly strong axle, of course, but its axle tubes are exactly the same diameter and thickness as what come with a Dana 35c. That means in a tough wheeling situation, the axle housing can flex… sometimes enough to cause breakage which is often a busted axle shaft or sometimes, the ring & pinion gears. That can ruin your whole day on the trail. With some lockers that can be taken out by a busted axle shaft, that can also present a major problem on the trail.

That Dana 44 axle flex issue has been well addressed by Superior Axle’s newly announced Dana 44 axle truss system. Consisting of a new braced differential cover and two heavily constructed braces that secure to the axle tubes with oversized u-bolts, it was designed with the serious off-roader in mind. And since the Dana 35c uses the same axle tubes that can also flex, Superior Axle has a similar axle truss kit for you Dana 35c owners too.



The kit is very complete and contains everything you see here with the exception of the two quarts of non-synthetic Currie 85W-140 GL-6 gear lube that are not part of the kit.



This is my Dana 44 axle just before mounting the truss. Now that I look at the axle tubes, they do look pretty skinny don't they. For cleaning purposes, I sprayed Simple Green onto the differential cover just before the photo was taken, that’s why it looks so nasty.

The blue brace between the track bar mount and differential cover is a track bar brace made by Jason Bunch over at Tri-County Gear. Superior Axle’s kit also includes a track bar brace but due to some dimensional changes on my axle, I had to retain the Tri-County Gear brace. If you don’t have a track bar brace and you wheel with big tires, the track bar brace in this kit will save your track bar mounting bracket some day.
 
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#2 ·


The first thing you do is remove the cover and drain the old gear lube. Leave the top bolt of the cover loosely threaded in while prying the cover open, that will stop the cover from falling off into your catch basin and prevent a smelly mess all over your garage floor.

 
#3 ·


Remove the brake line clamp and breather hose assembly. You will not have to bleed the brake lines afterwards.



As you can see, the brace is well constructed, it’s heavy!! Those large u-bolts are what secure it to the axle tubes. Don’t over-tighten the u-bolts; tighten them to 30 ft-lbs. using a torque wrench to avoid crushing the tubes.



The left and right braces are only loosely positioned until the center differential cover is installed.
 
#4 ·


This piece is inserted inside of the axle tube from the side and provides the blind nuts used to hold the shock absorber mounting bracket bolts in place. This is a very cool way to place blind nuts inside the tube for ease of assembly.



The four internal brackets you see here are what secure the outer braces to the differential cover. It’s a very cool design where the cover is placed over the top of those brackets and bolted into place after applying RTV sealant to the differential cover. This is also what does the final up-down positioning of the braces on the axle tubes. It’s important not to tighten any of the u-bolts before this step is completed.

 
#5 ·


Now you can start tightening things up. The bolts that hold the internal braces between the cover and L/R braces are tightened to 40 ft-lbs.



The truss is now one rigid piece and you can now tighten the u-bolts to their required 30 ft-lbs. Remember, don't over tighten the u-bolts as they are so beefy they could conceivably collapse the axle tube.



I have a CV driveshaft so the axle housing is rotated enough that it’s hard to fill the axle housing with enough gear lube. Flat on the ground, it takes less than a quart before it overflows out through the fill hole. With the Jeep raked steeply as in the above photo, with more angle given by removing the front wheels, I can overfill the fill hole to get the required amount of gear lube into the axle. The truss kit comes with a magnetic differential fill hole bolt that is pre-wrapped with Teflon tape, the designers of this kit thought of everything.
 
#6 · (Edited by Moderator)


Finished!

On quality of design and beefiness, I give it a good solid two thumbs-up. The design is impressive. It’s not easy to come up with an axle truss that is both uber-strong and also give the ability to remove the differential cover without having to remove the truss. With a stock Dana 44 (a Dana 35c version is also available) axle, this is strictly a bolt-on kit with no modifications needed. So for degree of difficulty, it’s an easy kit with no special tools other than a torque wrench needed. Nor do you need to be anything more than a “Joe Shade-tree Mechanic” for this job; no special talents or skills are needed. So on a difficulty scale of from one-to-five bananas, I give it a three for it being not a difficult job at all.

You’ll see trusses on the high-end axles like Ford 9” on the toughest rock crawling trails but those are pretty simple to design due to the fact they don’t have a rear differential cover that has to be removable like our Dana 44 and Dana 35c axles require. That the designers came up with a truss design that allows for that is very awesome. It wasn’t easy but to use an engineering term, the solution they came up with is nothing short of elegant.

If you wheel your Jeep and you’re out doing some fairly moderate or tougher trails, this truss kit might just save you from a major breakage on the trail. At $399 for the complete kit from Superior Axle, I consider it to be very cheap insurance. Superior Axle and Gear Don’t look for the truss kit on their website yet however, it’s not there yet. If you wheel your Jeep, get it! :punk:
 
#30 ·
Finished!

On quality of design and beefiness, I give it a good solid two thumbs-up. The design is impressive. It’s not easy to come up with an axle truss that is both uber-strong and also give the ability to remove the differential cover without having to remove the truss. With a stock Dana 44 (a Dana 35c version is also available) axle, this is strictly a bolt-on kit with no modifications needed. So for degree of difficulty, it’s an easy kit with no special tools other than a torque wrench needed. Nor do you need to be anything more than a “Joe Shade-tree Mechanic” for this job; no special talents or skills are needed. So on a difficulty scale of from one-to-five bananas, I give it a three for it being not a difficult job at all.

You’ll see trusses on the high-end axles like Ford 9” on the toughest rock crawling trails but those are pretty simple to design due to the fact they don’t have a rear differential cover that has to be removable like our Dana 44 and Dana 35c axles require. That the designers came up with a truss design that allows for that is very awesome. It wasn’t easy but to use an engineering term, the solution they came up with is nothing short of elegant.

If you wheel your Jeep and you’re out doing some fairly moderate or tougher trails, this truss kit might just save you from a major breakage on the trail. At $399 for the complete kit from Superior Axle, I consider it to be very cheap insurance. Superior Axle and Gear Don’t look for the truss kit on their website yet however, it’s not there yet. If you wheel your Jeep, get it! :punk:
From his post above. :cool:
 
#8 ·
does it keep the stock shockmounts?
 
#9 ·
Jerry - Cool! Good write-up too.

One thing I'd worry about - the U-bolts - since there's a possibility of crushing the tube by tightening the U-bolts too much (just to 30 'lbs) - what happens on an extreme situation where the brace is pulling down on the U-bolts? Seems like the pulling on the U-bolts could also crush the axle tube?

Seems like a short section of a half a tube fitted on the "U" side of the bolts would help distribute the load to help prevent that crushing.

I saw the after effects of a guy that put on a diff skid that mounted with U-bolts to the axle - hogged them down with an impact, crushed both tubes.
 
#10 ·
wow.. what kind of rear trackbar is that jerry?
 
#11 ·
The track bar itself is a Rubicon Express, the blue thing you see is a Tri-County Gear brace that goes between the differential cover mounting bolts and the trackbar mount. The OE trackbar mount has a nasty habit of tearing off where it is welded to the axle with big tires on a tough trail so the brace prevents that. The Superior Axle kit includes its own version of a trackbar brace that works just as well. I had just changed a few dimensions previously so it was easier to retain the Tri-County Gear brace though I will install the Superior Axle version the next time I pull the diff cover.

Rich, the truss forms a very rigid brace attached to the rear of the axle with the load distributed very evenly across the entire axle housing. It's only during the tightening process where an individual u-bolt shouldn't be overtightened, just like the u-bolts that hold leaf spring perches to an axle tube that shouldn't be overtightened either... just tighten to 30 ft-lbs as in the directions and there's no issue. On the trail, the load is carried more by the truss itself with the u-bolts carrying little of the actual stress. Typical the most stress is encountered when you're climbing up an obstacle and the axle is trying to flex back & forth (up and down when the Jeep is oriented vertically) rather than up & down. I hope that made sense.

And yes, it retains the stock shock mounts and uses them for the extended shock mounts included in the kit. :)
 
#13 ·
thanks for the helpful information again jerry :wavey:

that blue bracket your speaking of is pretty neat looking
 
#14 ·
Larry, only the Rubicon version of the Dana 44 has a built-in gear lube drain. I've yet to see a cover for a standard D44 with a drain in the cover itself. It's really better to pull the cover anyway to inspect the R&P gear for broken teeth, chips, damage etc. when replacing the gear lube. Even if the cover had a drain, I doubt I'd ever use it for normal gear lube changes. :)
 
#19 ·
yeah, this would get old after awhile...

...but I know Jerry considers it just extra quality time with something he really enjoys doing... wrenching on jeeps :). But don't try that if you have the flimsy thin hat rotors though from earlier model years cuz they could collapse

*interesting product by the way. I know that if my rear tj d44 wasn't trussed it wouldve bent like my front did. Mine is trussed with the one from RK that came with the long arm kit for the upper triangulated arms.
 
#21 ·
This would be a nice bolt on solution for anyone that has short arms. As soon as you go to a triangulated upper control arms setup there's no way you'd be able to get the ubolts around any cradle. However a cradle is like a truss on the rear anyway so potentialy you would'nt have as much need for it.

Jerry, did Blaine and Supperior think of coming out with a weld on version of the truss for those that are into making more permanent solutions that don't involve ubolts? I can envision landing hard on that truss and ripping out diff cover bolts because it tries to rotate the truss.

And how much gear lube are you trying to put in your axle? I've had CV driveshafts in mine for years and have always been able to get the required 2 quarts of oil in the axle. You don't want anymore than that or it will start coming out of your breather. :D
 
#22 ·
Jack, I probably have around 1.6 to maybe 1.7 quarts in there. I've never even heard of anyone getting a full two quarts into their D44. :confused:

No weld-on version is contemplated. The way the braces fit so closely into the axle, I don't see much chance of them being rotated upwards any at all. It's pretty darned solid, I don't think Blaine would be associated with anything that couldn't take whatever JV could throw at it. :)
 
#24 ·
HA, I'm proof that you can get the full two quarts in with out running over the tubes. Of course at 104" My pinion angle isn't as much as yours. :D
 
#26 ·
Lost, that question came up elsewhere and this is from the co-developer (Blaine Johnson) of the truss... "It's the heavier Dana cover that has a diff ring laser cut for the circumference with the bolt holes in it and new longer bolts are supplied. "
 
#27 ·
Yup, sounds like it's the same cover that Alloy was selling before they went out of business. I can say that it is a thicker cover and should be able to hold the brackets for the truss. Dana makes a variety of things and I believe they are the manufacturer of that cover they just don't brand it as such.
 
#28 ·
Jerry,

I've seen other Superior stuff on JF. Is the D35 verison of this available yet as well? I have the upgraded shafts and turn 33's with an ARB locker. If I could truss up the D35, I think my 4 banger would be happy for a long while to come. :)
 
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