Revolution USA Made Front Axle Shaft Installation

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This is a walk through of the assembly and installation for a pair of Revolution Gear and Axle USA made cromoly front axle shafts.

Several weeks ago I managed to break a front driver's side Superior cromoly axle shaft with a Spicer 5-760 u-joint.
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In my situation, the Jeep was stuck with a rock behind the rear diff and a rock in front of the driver's side tire. The break occurred at full driver's steering lock while trying to climb up and over. I believe the u joint cracked which led to the ear on the stub folding over.

Most aftermarket axle shafts use the factory size 5-760 u joint. Superior did. Revolution offers a similar shaft in their Discovery line of imported shafts. While I'm sure these are a very good option for most users, there is a bigger, stronger option that fits the stock TJ Dana 30 and Dana 44 axle.
 
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RGA offers a USA made shaft that uses a 1350 u-joint. As you will soon see, this is going to be the largest u-joint that will physically fit in a stock TJ front axle.

Dana 30
https://www.revolutiongear.com/product/97_06_tj_lj_xj_and_zj_us_made_front_axle_kit_27_spline
Rubicon 44
https://www.revolutiongear.com/product/03_06_tj_and_lj_rubicon_us_made_front_axle_kit
5-760 u-joint over a 1350
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RGA, Superior, Factory
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Superior and factory use the same u-joint and are effectively the same physical size, just different material.
 
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I won't go into the process of installing u-joints. Some use a shop or ball joint press. I prefer a hammer and you should too.

RGA uses full circle clips which means a snap ring pliers is needed. A small bag of 8 clips will be taped to one of the supplied Spicer u-joint boxes. Save yourself some frustration and get something better than the Channellock that I have.
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The circle clips must be installed loose on the cross prior to installation. If this is not done, you will not be able to attach the clips later on.
20200822_075935.jpg

As always, do not mix up the caps on the cross. Doing so will mess up the even distribution of grease and lead to premature failure of one cap before the others.

The RGA ears have a step in the inside of the yoke.
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In the event that it matters, I made sure to position the split on the step where it is fully supported.
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Shove the shafts in and you are done. Go and have fun.

Maybe.

My Jeep does not have extended steering stops, nor do I want to have any extension. This, along with a few other projects, has me looking hard to make sure I can get all of my usable steering.

We can see that the shaft yokes are really really close to the unit bearing bolts. Spin the shaft by hand and you will likely notice a light tick as the yokes and caps contact the unit bearing flange bolts.
20200822_133311.jpg


The reality is that the shafts are harder than the bolts are. This is after a week of "self clearencing". More on this in a bit.
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Another thing to watch for is the ears contacting the yokes at full lock. Presumably due to minor variations in the forgings, on mine one side was more prominent than the other. While the passenger side had a light pulse when spun by hand, the driver's side would lock up. Again, I suspect that this would quickly and harmlessly fix itself. But I used a file on the tips until the interference was gone. Very little material was removed.
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Over the years, I have read and heard about the need to clearance the unit bearing bolts. This is an example of what I think many do.
20200829_085707.jpg


This will work once and only once. Given the parts we are working on, the tools we use and variations in temperature, stray oils, overall cleanliness, and our inability to be consistent, these bolts will never land in the same position the next time they get reinstalled.

As stated earlier, I am unsure if this clearencing needs to be done in the first place. But if you are going to do it, here is how.

20200829_112828.jpg

Looking again at my set of self clearanced unit bearing bolts, I picked the hardest hit one and chucked it into a drill press. A hand held drill will also work. While spinning, I worked the flange with a flap disc until the gouge disappeared. A file will also do the job.
20200829_105204.jpg


Measuring this with a caliper, I took the remaining 5 bolts down to the same dimension. These begin at an inch and I reduced them down to a hair over 7/8".

Looking a third time at the self clearanced bolts and you will see one of the bolt heads had the corner knocked off as well. This is the forward most bolt, middle in the stack from the ground. I did the same with the drill and flap disc and took off the top corner until there was a bit of room between the bolt and shaft yokes.
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I believe this covers everything one might encounter when assembling and installing these enormous axle shafts. The practical need to clearance is debatable. Check yours, see what is going on and decide for yourself. Either way, these USA shafts should be really difficult to break.
 
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Shove the shafts in and you are done. Go and have fun.

Maybe.

My Jeep does not have extended steering stops, nor do I want to have any. This, along with a few other projects, has me looking hard to make sure I can get all of my usable steering.

We can see that the shaft yokes are really really close to the unit bearing bolts. Spin the shaft by hand and you will likely notice a light tick as the yokes and caps contact the unit bearing flange bolts.
View attachment 186980

The reality is that the shafts are harder than the bolts are. This is after a week of "self clearencing". More on this in a bit.
View attachment 186986

Another thing to watch for is the ears contacting the yokes at full lock. Presumably due to minor variations in the forgings, on mine one side was more prominent than the other. While passenger side had a light pulse when spun by hand, the driver's side would lock up. Again, I suspect that this would quickly and harmlessly fix itself. But I used a file on the tips until the interference was gone. Very little material was removed.
View attachment 186979
Your shaft to yoke interference looks like leftover casting flash that wasn't fully removed. Easy fix.

The flange bolt fix looks fairly straightforward too...spin the bolt in a lathe (or drill press) and remove some OD from the flange of the bolt.

Just curious. What is the cost different between these and RCV's? Any other reasons you decided against RCV?
 
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...

Just curious. What is the cost different between these and RCV's? Any other reasons you decided against RCV?

The little bit that I looked, RCVs were a few hundred more, though I recall a few have found them for closer to the same cost as RGA. Beyond that, RCVs have a reputation for clicking and the install and rebuild process looks really irritating. I guess I don't see their benefit for my purposes.
 
The little bit that I looked, RCVs were a few hundred more, though I recall a few have found them for closer to the same cost as RGA. Beyond that, RCVs have a reputation for clicking and the install and rebuild process looks really irritating. I guess I don't see their benefit for my purposes.
Fair enough. I know you generally don't let cost sway your decisions too much, but I wasn't sure if there was a strength difference or anything. The install think DOES look irritating. If I recall, the Birfield joint that RCV uses has a better operating angle than U-joints...but I might be making that up.
 
The little bit that I looked, RCVs were a few hundred more, though I recall a few have found them for closer to the same cost as RGA. Beyond that, RCVs have a reputation for clicking and the install and rebuild process looks really irritating. I guess I don't see their benefit for my purposes.

Isn't one of the advantages of the RCVs that you can make full lock turns in 4WD and not have to worry about the u-joints binding up or clicking and potentially breaking off one of the ears?

I have no experience with that, but I could have sworn I had read something about it somewhere, at some point. Maybe that's just wrong entirely, I just thought that was one of the benefits of the CV is that at any given angle there was no chance of them binding up.

My new one has these Revolution shafts anyways (y)
 
Fair enough. I know you generally don't let cost sway your decisions too much, but I wasn't sure if there was a strength difference or anything. The install think DOES look irritating. If I recall, the Birfield joint that RCV uses has a better operating angle than U-joints...but I might be making that up.

If the angle is better, I can't use it. Mine is already at the stock steering stops with no sign of bind. :)
 
Isn't one of the advantages of the RCVs that you can make full lock turns in 4WD and not have to worry about the u-joints binding up or clicking and potentially breaking off one of the ears?

I have no experience with that, but I could have sworn I had read something about it somewhere, at some point. Maybe that's just wrong entirely, I just thought that was one of the benefits of the CV is that at any given angle there was no chance of them binding up.

...

That sounds like something RCV might say. First, there isn't any bind. Second, if the axles are locked, where is the bind really coming from and how do RCVs prevent that?
 
Isn't one of the advantages of the RCVs that you can make full lock turns in 4WD and not have to worry about the u-joints binding up or clicking and potentially breaking off one of the ears?

Off the top of my head ujoints allow for around 37*, RCV joints allow for around 45*. I was able to take advantage of this on my LJ build.
 
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Off the top of my head ujoints allow for around 37*, RCV joints allow for around 45*. I was able to take advantage of this on my LJ build.

Okay, so there is some truth to this, it just depends on the build, right?

It would be interesting to test this out with my current TJ. How did you go about doing this test? Did you do it while cycling the suspension?
 
Okay, so there is some truth to this, it just depends on the build, right?

It would be interesting to test this out with my current TJ. How did you go about doing this test? Did you do it while cycling the suspension?

I think I can get a range of motion measurement on mine, stop to stop.
 
I think I can get a range of motion measurement on mine, stop to stop.

That would be interesting to hear. I know @toximus is running 37s whereas you and I are running 35s, so it would be interesting to see how your number differs from the 45° he came up with.