Do I really need a transfer case drop kit for a 4" lift?

[jjvw]

If the lowers aren't also used, you will run the risk of the diff and track bar bracket hitting the gas tank.

 

[ElDuderino]

The only meaningful difference is the already eliminated slip yoke. And the digital speedo. All the other concerns still apply.

The problem you may have seen out in the wild is that there is a lot of misinformation on the Rubicon.

Just remembered one I saw...what about a shorter transfer case and slightly longer rear shaft?

 

[jjvw]

Just remembered one I saw...what about a shorter transfer case and slightly longer rear shaft?

That would be the regular 231 t-case with a super short slip yoke eliminator. That route is a more expensive and involved fix than what you need to do to solve your issues. The result would be similar enough and you would give up the 4:1, if that aspect of the Rubicon is of value to you.

 

[ElDuderino]

That would be the regular 231 t-case with a super short slip yoke eliminator. That route is a more expensive and involved fix than what you need to do to solve your issues. The result would be similar enough and you would give up the 4:1, if that aspect of the Rubicon is of value to you.

I meant is that another rubicon difference?

 

[jjvw]

I meant is that another rubicon difference?

If you are going to add a raised transfer case skid and are building to the limits of travel, the shorter 241 rear drive shaft will run out of travel before a 231 will.

 

[Kenneth G Zinis]

Sorry guys, late to this party. I'd like to remove my 1 1/4 " TC drop on my Rubi. Why waste ground clearance! Have 4" lift by PO. CV on front axle with SYEs on both shafts. Engine sits at high downward angle toward currently. I have adjustable rear arms. Can I just remove the drop adjust the arms with no other mods?

 

[Jerry Bransford]

Sorry guys, late to this party. I'd like to remove my 1 1/4 " TC drop on my Rubi. Why waste ground clearance! Have 4" lift by PO. CV on front axle with SYEs on both shafts. Engine sits at high downward angle toward currently. I have adjustable rear arms. Can I just remove the drop adjust the arms with no other mods?

You can't remove the TC drop with the stock OE single-cardan driveshaft in the rear, the angles are too steep for its two u-joints. But you could remove the TC drop if you replaced the rear driveshaft with a double-cardan driveshaft... the kind with a CV joint at one end like your front driveshaft has. Tom Wood can make one for you.

 

[Kenneth G Zinis]

You can't remove the TC drop with the stock OE single-cardan driveshaft in the rear, the angles are too steep for its two u-joints. But you could remove the TC drop if you replaced the rear driveshaft with a double-cardan driveshaft... the kind with a CV joint at one end like your front driveshaft has. Tom Wood can make one for you.

Thanks Jerry, any idea what this would cost?

 

[Jerry Bransford]

Thanks Jerry, any idea what this would cost?

Call Tom, Shawn, etc. at www.4xshaft.com who can tell you exactly.

 

[Kenneth G Zinis]

Thanks Jerry

 

[Armytruck6x6]

My understand is that you can do a motor mount lift a 3rd option to the SYE or tcase drop. Haven't tried it though????

 

[Kenneth G Zinis]

You can't remove the TC drop with the stock OE single-cardan driveshaft in the rear, the angles are too steep for its two u-joints. But you could remove the TC drop if you replaced the rear driveshaft with a double-cardan driveshaft... the kind with a CV joint at one end like your front driveshaft has. Tom Wood can make one for you.

Hi Jerry,
I took your advice and obtained a Tom Wood double-cardan joint rear shaft for my '03 Rubi. It has 4" lift. So I plan to remove TC drop spacer. Must I also adjust the rear axle arms as part of the DS install? Can you refer me to any detailed instructions to follow. Thank you

 

[Jerry Bransford]

Hi Jerry,
I took your advice and obtained a Tom Wood double-cardan joint rear shaft for my '03 Rubi. It has 4" lift. So I plan to remove TC drop spacer. Must I also adjust the rear axle arms as part of the DS install? Can you refer me to any detailed instructions to follow. Thank you

I don't know of specific detailed instructions but the idea of what needs to be done is simple. The rear upper arms need to be lengthened and the rear lower arms need to be shortened. When they are shortened & lengthened the correct amounts, that raises the pinion angle upward to match the angle of the rear driveshaft which is the end-result that you need to happen for your new TW CV driveshaft.

A quick & dirty way would be to adjust the lower adjustable length control arms to the exact same length as the factory lower control arms. Then, with the upper adjustable length control arms disconnected at one end, use a jack under the nose of your rear axle to push it up until the pinion shaft is pointing directly up the driveshaft and at the CV joint. Actually just a tiny bit above since it will lower down a tad once the jack is removed. Once the pinion angle is correct, adjust the lengths of the upper control arms so their bolt holes match the bolt holes in the brackets and slide the bolts in. Again, adjust the angle upward with the jack just enough so the angle is just slightly above what you need and when you're done, the pinion angle will drop down a tad and if you did it right, it'll be what you need.

This is how your rear axle's pinion angle must look... courtesy of Tom Wood's website.

 

[Kenneth G Zinis]

I don't know of specific detailed instructions but the idea of what needs to be done is simple. The rear upper arms need to be lengthened and the rear lower arms need to be shortened. When they are shortened & lengthened the correct amounts, that raises the pinion angle upward to match the angle of the rear driveshaft which is the end-result that you need to happen for your new TW CV driveshaft.

A quick & dirty way would be to adjust the lower adjustable length control arms to the exact same length as the factory lower control arms. Then, with the upper adjustable length control arms disconnected at one end, use a jack under the nose of your rear axle to push it up until the pinion shaft is pointing directly up the driveshaft and at the CV joint. Actually just a tiny bit above since it will lower down a tad once the jack is removed. Once the pinion angle is correct, adjust the lengths of the upper control arms so their bolt holes match the bolt holes in the brackets and slide the bolts in. Again, adjust the angle upward with the jack just enough so the angle is just slightly above what you need and when you're done, the pinion angle will drop down a tad and if you did it right, it'll be what you need.

This is how your rear axle's pinion angle must look... courtesy of Tom Wood's website.

View attachment 90499

Thanks Jerry!

 

[Kenneth G Zinis]

Thanks Jerry!

Jerry,
Thanks for the directions, however I don't have or know length of stock arms. Should I just eyeball by equalizing lengths of both sets of arms to achieve the angle required?

 

[Jerry Bransford]

Jerry,
Thanks for the directions, however I don't have or know length of stock arms. Should I just eyeball by equalizing lengths of both sets of arms to achieve the angle required?

The lower arm lengths are probably ok as is. Lengthen the uppers until you get the right pinion angle. If you find you need to move the axle forward or back once the correct pinion angle is achieved, just shorten/lengthen the uppers & lower arms together the exact same amount by turning all four arms the exact same number of turns so their lengths shorten/lengthen the same amount.

 

[Kenneth G Zinis]

The lower arm lengths are probably ok as is. Lengthen the uppers until you get the right pinion angle. If you find you need to move the axle forward or back once the correct pinion angle is achieved, just shorten/lengthen the uppers & lower arms together the exact same amount by turning all four arms the exact same number of turns so their lengths shorten/lengthen the same amount.

Thanks again Jerry!

 

[Kenneth G Zinis]

The lower arm lengths are probably ok as is. Lengthen the uppers until you get the right pinion angle. If you find you need to move the axle forward or back once the correct pinion angle is achieved, just shorten/lengthen the uppers & lower arms together the exact same amount by turning all four arms the exact same number of turns so their lengths shorten/lengthen the same amount.

Jerry,
I believe I should do following:
1 remove rr DS
2 remove TC spacer
3 remount TC
4 bolt front of DS to harmonic bal
5 adjust upper arms to get pinion to line up with (just slightly above) back portion of CV joint

Correct?

Thanks.

 

[Jerry Bransford]

Correct, but aim the pinion up directly in line with the driveshaft so it's pointing directly at the CV joint.

 

[HarleyMick]

The drive shaft is kind of like a universal socket adapter with the U joints. The less the angle the better it works.