Hi new to this thread i havea 04 tj with a 4in lift and a sye it has a tcase drop already installed is it really necessary
Do I really need a transfer case drop kit for a 4" lift?
- Thread starter AZ2CO98tj
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Yes, it's absolutely necessary unless you want to destroy your driveshaft and transfer case.
Unless you have a SYE, double cardan driveshaft, and adjustable rear control arms.
Highly unlikely. Do you have adjustable control arms to match the SYE and double cardan rear driveshaft?
I have the double cardan rear driveshaft but no adjustable control arms it is a skyjacker 4 inch lift
You need a SYE and adjustable control arms if you want to get rid of the transfer case drop.
Whoever installed that DC rear driveshaft should have also installed adjustable length control arms, at least the uppers on the rear axle. They're required to raise the rear axle's pinion angle to match the requirements of that type of driveshaft.
The top drawing shows how the pinion angle must to be set for a double-cardan (aka CV) driveshaft. The bottom drawing shows how Jeep set the angle for the OE conventional driveshaft. Drawings courtesy of Tom Wood's Custom Driveshafts.
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Skyjacker. I see.
Are the control arms factory? Post pictures. Include a clear side view showing the rear pinion and the transfer case ouput. We need to see the alignment of the drive shaft.
I will have to look again but i am positive they are not adjustable i bought the jeep the way it is i plan on converting to a long arm kit soon possibly building my own
Long arms are a whole different discussion. Do your research and stay away from the bolt on kits.
Don't do a long arm kit... big waste of money on a TJ (unless you like being hung up on everything to go over, or you plan on having 20" of lift 
).
If you really wanted to do it right, a mid-arm kit (i.e. Savvy or GenRight) is considered the best option.
).If you really wanted to do it right, a mid-arm kit (i.e. Savvy or GenRight) is considered the best option.
There are NO bolt-on long-arm kits that I'd install. Having done one and ran it for 5-6 years, I learned they don't work as well offroad as a good quality short-arm does. All my previous TJ's long arm suspension did better was the get hung up on rocks far more easily than my present Currie 4" short-arm suspension does that otherwise outperforms it in all regards,
The only time you can make longer-than-stock control arms work is with custom installations with a lot of trial-and-error. The best current suspension that has longer control arms is Savvy's mid-arm suspension which even it requires significant expertise to install properly.
All of these pics show different times my previous TJ's long-arms were hung up on rocks.
Xposure
TJ Enthusiast
Jerry, where you said “should have also installed adjustable length control arms, ‘at least the lowers’ on the rear axle.”......I was under the impression the uppers were better for adjusting pinion angle. Am I wrong about that?
Severe inexcusable brain fart, I did mean uppers. I'll go correct it, thanks for catching it!!
Xposure
TJ Enthusiast
Okay, I thought I was having a brain fart....sometimes I feel like I’m living in that state. Haha
Xposure
TJ Enthusiast
Looking at your diagram, I suppose I need to determine what style driveshaft I have before I swap out my upper control arms to change the angle. I have a 8.8 with stock upper control arms. I haven’t measure and it’s not in front of me, but I’m fairly certain the pinion is fairly parallel with the transfer case (which has a 1” drop). I was fixing to order uppers to change the angle to make the pinion in line with the driveshaft but based on your picture that depends on the type of driveshaft.....correct? That my current setup may be designed more like your bottom image? I do NOT have a SYE. It’s a 4” lift with a 1” transfer case drop.
Without a SYE kit your driveshaft is like the bottom image showing a conventional 2 u-joint driveshaft. Your 8.8's rear pinion angle needs to remain parallel to the tcase output shaft until/if you install a SYE kit and CV driveshaft. A 4" lift is really too tall and the angles it produces at your rear driveshaft's u-joints are really too steep for the u-joints, which is why we always recommend a SYE kit and CV driveshaft for SWB TJs. LWB Unlimiteds can get away without a SYE kit with a 4" lift due to its longer rear driveshaft reducing the angles seen by the u-joints.
I just installed the rc 4 inch lift with the transfer case drop and rc 4-6 inch lift dc driveshaft on my 04 rubicon do you think ill have any issues?
Medali
TJ Enthusiast
Hello
I just ordered a box drop :
https://www.jeeperstore.com/kit-de-...hane-de-2-a-4-de-rehausse-jeep-wrangler-yj-tj
the detail provided by the seller says that it is for lift kit from 2 '' to 4 ''
Since I only have 1.5 '' lift back (and 3 '' at the front), does installing this kit will not create extra vibration for my car?
Actually I only feel vibration when exceeding 100km / h.
I just ordered a box drop :
https://www.jeeperstore.com/kit-de-...hane-de-2-a-4-de-rehausse-jeep-wrangler-yj-tj
the detail provided by the seller says that it is for lift kit from 2 '' to 4 ''
Since I only have 1.5 '' lift back (and 3 '' at the front), does installing this kit will not create extra vibration for my car?
Actually I only feel vibration when exceeding 100km / h.