# Get Out And Explore! > Tech Section >  Tech Talk Power Train - Transmission/Axles/Transfer Case/Driveshafts and more

## FSHJNKY

Are you having issues with your powertrain? Thinking about upgrading your axles or driveshafts? Whatever your need, want or desire this is the place to ask the questions and get the answers. 
All powertrain related questions will be moved to this thread for organization and simplifying the search functionality of the site.

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## J&J

2017 JK Rubicon. To gusset, or not to gusset the inner c's. That is the question.

Amongst the upgrades happening this winter, a 3" lift and 35's. One of the things I've seen break on a JK is the front axle-side track bar mount. Since I will not be adding any components capable of reinforcing this mount (yet), I will be adding a couple gussets there for insurance. The rear track bar will be getting a relocation bracket, adding strength, and the frame side of both the front and back are getting reinforcement brackets. Anyway, this got me to thinking if there's anything else I should be concerned with reinforcing, such as the inner c's. Some relevant considerations: 35" tires, 4" backspacing, which is not as far out as it sounds with a wheel width of 7". It is a fairly heavy rig for a JK, bumpers / skids / winch/ rooftop tent / gear, but weight-wise it's no JKU. I like to wheel "challenging" and will be on increasingly demanding trails to match the enhanced capabilities of the rig. However, nothing too extreme, not a lot of bumping, no high speed runs, no jumps. Just slow crawling. I'll likely hit potholes harder than I hit anything on the trail. It is my feeling that I should not worry about bending the c's or the axle, but I'm looking for opinions on the subject.

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## FSHJNKY

> 2017 JK Rubicon. To gusset, or not to gusset the inner c's. That is the question.
> 
> Amongst the upgrades happening this winter, a 3" lift and 35's. One of the things I've seen break on a JK is the front axle-side track bar mount. Since I will not be adding any components capable of reinforcing this mount (yet), I will be adding a couple gussets there for insurance. The rear track bar will be getting a relocation bracket, adding strength, and the frame side of both the front and back are getting reinforcement brackets. Anyway, this got me to thinking if there's anything else I should be concerned with reinforcing, such as the inner c's. Some relevant considerations: 35" tires, 4" backspacing, which is not as far out as it sounds with a wheel width of 7". It is a fairly heavy rig for a JK, bumpers / skids / winch/ rooftop tent / gear, but weight-wise it's no JKU. I like to wheel "challenging" and will be on increasingly demanding trails to match the enhanced capabilities of the rig. However, nothing too extreme, not a lot of bumping, no high speed runs, no jumps. Just slow crawling. I'll likely hit potholes harder than I hit anything on the trail. It is my feeling that I should not worry about bending the c's or the axle, but I'm looking for opinions on the subject.


I had my front axle sleeved and Gusseted when I went up to 35s. EVO makes a sleeve and gusset kit for the JK.

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## Rubicon

> I had my front axle sleeved and Gusseted when I went up to 35s. EVO makes a sleeve and gusset kit for the JK.


That was quite a day, but well worth it!
I still want to do Erin's JK, even though she only has 33's and probably won't go up in size.

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## NotThePainter

Agnes, a '95 YJ, has two problems up front and I think the solution is related.

To set up the situation the rig is completely non-stock. Mods include


4 cylinder engine moved forwards a few inchessm465 transmission, which is shorter than the original, but the non-standard bell housing and adaptors have made the whole assembly longerRock Track transfer case.shackle reversal

The rear driveshaft is fine. It was measured and build by Adams. The front driveshaft is stock and it just happened to work. The first problem is that it falls out on the trail under what is now predictable situations. Typically, I get hung up and am reversing or being winched backwards. This lets the front shackle, which is on the rear of the spring, to move forward quite a lot, extending the driveshaft and it pops out.



The second failure has only happened a few times, but the front shackle invert and now we need to be super careful to get it back. The standard fix for shackle inversion is to use a boomerang shackle, but that only works when you don't have a shackle reversal in place. There isn't anyplace on the frame for the bommerang to hit.



So just getting a longer front driveshaft is not the solution, we'll still get inversion. Tundra suggested that I install a limiting strap. I was initially against this but since I can get full droop a strap shouldn't hurt articulation and it should limit the front axle from moving forward which both keeps the driveshaft intact and should prevent inversion.

Are there any other suggestions? I think the straps would be attached to the transfer case skid plate so they would prevent forward movement. I would need to use springs of some sort to hold them up off the ground.

And to make it more complicated, I need to replace my front springs. I broke a military wrap on one of them at Field and Forest last fall, so I don't even know what my ride height will be until that is done and settled, something something adjustable would be nice and it also seems that those are available.

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## Rubicon

> Agnes, a '95 YJ, has two problems up front and I think the solution is related.
> 
> To set up the situation the rig is completely non-stock. Mods include
> 
> 4 cylinder engine moved forwards a few inchessm465 transmission, which is shorter than the original, but the non-standard bell housing and adaptors have made the whole assembly longerRock Track transfer case.shackle reversal
> 
> The rear driveshaft is fine. It was measured and build by Adams. The front driveshaft is stock and it just happened to work. The first problem is that it falls out on the trail under what is now predictable situations. Typically, I get hung up and am reversing or being winched backwards. This lets the front shackle, which is on the rear of the spring, to move forward quite a lot, extending the driveshaft and it pops out.
> 
> The second failure has only happened a few times, but the front shackle invert and now we need to be super careful to get it back. The standard fix for shackle inversion is to use a boomerang shackle, but that only works when you don't have a shackle reversal in place. There isn't anyplace on the frame for the bommerang to hit.
> ...


Seeing how you already need leaf springs: longer custom springs AND longer splines propeller shaft.

Or a BDS coil spring conversion kit. I installed on one YJ, and was not so much impressed with the performance gain(albeit not broke in yet), but it fixed axle centering for less driveshaft issues AND no inversion ;)

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## NotThePainter

> Or a BDS coil spring conversion kit. I installed on one YJ, and was not so much impressed with the performance gain(albeit not broke in yet), but it fixed axle centering for less driveshaft issues AND no inversion ;)


But you would all have to visit my grave on your way to visiting Glenn in prison after he killed me.

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## Ivoryring

> But you would all have to visit my grave on your way to visiting Glenn in prison after he killed me.


I've seen plenty of graveyards in the woods on Class VIs. Just saying.

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## BlueberryHill

> But you would all have to visit my grave on your way to visiting Glenn in prison after he killed me.


Agnes can never be converted to coil springs, she is the Queen of the Ancient and Honorable Society of the Leaf Spring.

Long live the Queen of Badassery!

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## vballman

Couple of ideas for my 2dr non Rubicon I been thinking about. Can you swap out a transfer case from a Rubi to a non Rubi? I'd love to upgrade the axels as well, but one thing at a time. What is needed to swap out the transfer case and can it be done without doing the axels at this point? Thanks guys!

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## Rubicon

> But you would all have to visit my grave on your way to visiting Glenn in prison after he killed me.





> Agnes can never be converted to coil springs, she is the Queen of the Ancient and Honorable Society of the Leaf Spring.Long live the Queen of Badassery!


 It would still have them, just like a XJ Cherokee...in the rear ;)







> Couple of ideas for my 2dr non Rubicon I been thinking about. Can you swap out a transfer case from a Rubi to a non Rubi? I'd love to upgrade the axels as well, but one thing at a time. What is needed to swap out the transfer case and can it be done without doing the axels at this point? Thanks guys!


Yes.
Not 100% sure for a JK install.
And yes, but the line starts behind me Pete for a NV241OR(Off Road) RockTrac :p

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## Ivoryring

Last I looked Rubicon t-case is not cheap. You hear about people scoring one for cheap from time to time, but when I went to try to find one myself... Well... Not cheap.

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## Rubicon

> Last I looked Rubicon t-case is not cheap. You hear about people scoring one for cheap from time to time, but when I went to try to find one myself... Well... Not cheap.


Still hopeful...hoping to get the "cheap one" before Pete finds it ;P
What have you seen for prices now?

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## Ivoryring

> Still hopeful...hoping to get the "cheap one" before Pete finds it ;P
> What have you seen for prices now?


I haven't looked lately. Last time I looked was fall 2019, my memory was that it was around $2,000-$2,500 for 'as is off ebay'. My memory could easily be wrong on the price.

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## bob

JK Rubicon np241OR should be an easy swap into any JK as they all have the np241 case, so should be able to use same shafts. BUT, maybe input/output splines are different. Can't recall. 
But, as has been mentioned, cost will be a factor. My be cheaper to get a new Atlas.

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## Rubicon

> I haven't looked lately. Last time I looked was fall 2019, my memory was that it was around $2,000-$2,500 for 'as is off ebay'. My memory could easily be wrong on the price.


 :Eek6:

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## NotThePainter

My NOS TJ, not JK, rocktrac was $1,250.

But if you're building an Atlas, be sure to get the 4 speed. The wicked low crawl ratio is just so much fun! (But, last time I checked, at that was years ago, the 4 speed could only be used by manual JK, not an auto. And yes, Shawn, we know, we know...)

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## Rubicon

> My NOS TJ, not JK, rocktrac was $1,250.
> 
> But if you're building an Atlas, be sure to get the 4 speed. The wicked low crawl ratio is just so much fun! (But, last time I checked, at that was years ago, the 4 speed could only be used by manual JK, not an auto. And yes, Shawn, we know, we know...)


We know what?

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## vballman

Thanks guys, I'll definitely have to look into Atlas as well. Can always hope a junk yard comes up with one and doesn't know any better, LOL doubt it but one can hope.





> Still hopeful...hoping to get the "cheap one" before Pete finds it ;P


Guess the search is on Shawn and if I find one and don't have the cash, I'll be sure to let you know!

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## Rubicon

> Thanks guys, I'll definitely have to look into Atlas as well. Can always hope a junk yard comes up with one and doesn't know any better, LOL doubt it but one can hope. Guess the search is on Shawn and if I find one and don't have the cash, I'll be sure to let you know!


Haha, thanks :) I wish you good luck and hope you get lucky. Not really looking myself, but I will keep my eyes and ear open.

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