Do I really need a transfer case drop kit for a 4" lift?
- Thread starter AZ2CO98tj
- Start date
Be careful shortening the lower arms. I installed a TW double Cardan driveshaft and the slip joint would stack if the lower arms were shortened at all. I think the driveshaft should actually be a little shorter than it is.
Kenneth G Zinis
TJ Enthusiast
TurboTJ, Do you mean the slip yoke on transmission or the slip joint on DS? I have SYE
I mean the slip joint in the driveshaft. I have a Rubicon so I did not need to install an SYE. I just replaced the driveshaft with the TW double Cardan shaft designed for the TJR. When rotating the pinion, it had to be done by lengthening the upper arms only. Shortening the lower arms even a little bit caused the driveshaft slip joint to stack.
Brianj5600
TJ Expert
@Kenneth G Zinis, If you want to know how long to set your lowers, you can go through a whole process. The short version is to pull your springs, jounce bumpers and and upper CA's ( at least one end). Use a jack to put the axle at full bump. Adjust bumpstop if necessary (it might be, depending on who installed your lift). Set your lower CAs so that the axle pad is centered on the frame bumpstop. Now check the ensure the axle is square to the frame. Make adjustments to the lowers until it is square. They should be minor, if you centered the bumps carefully.
Now set pinion angle. Should be done with the weight of the car on the axle... So put your springs back in. Use a jack to get pinion angle correct, then adjust and install your upper arms to the correct length. They most likely will not be the same, side to side. That is ok. The bolts should slide in and out easily.
Long post, and I left out a bunch of details. This isn't a trivial thing to do, though it's not hard, per se. Just time consuming.
Now set pinion angle. Should be done with the weight of the car on the axle... So put your springs back in. Use a jack to get pinion angle correct, then adjust and install your upper arms to the correct length. They most likely will not be the same, side to side. That is ok. The bolts should slide in and out easily.
Long post, and I left out a bunch of details. This isn't a trivial thing to do, though it's not hard, per se. Just time consuming.
When they were originally put on they were adjusted to be the same length as the OEM arms. The upper arms are now longer because the pinion was rotated.
Brianj5600
TJ Expert
Thanks, I ordered a TJR DC driveshaft and using stock length non adjustable LCAs and adjustable uppers. I hope they all work together.
Kenneth G Zinis
TJ Enthusiast
Kenneth G Zinis
TJ Enthusiast
Kenneth G Zinis
TJ Enthusiast
I should add that the TW double Cardan driveshaft totally eliminated any hint of vibration. It works as advertised.
I have a 4" RC lift w/ transfer case lowered on my 03 TJ Sport. However, recently my Jeep starting making a loud chirping sound when driving. Took it to the local Brake Masters shop and they said front drive shaft was bent. So, I removed drive shaft. Called another drivetrain mechanic and he doubts the drive shaft is bent but suspects the u-joints are shot. I'm wondering if I should just replace the front drive shaft with one designed for lift. like Tom Woods or Adams. Or if original drive shaft isn't damage, just replace the u-joints. Any thoughts?
Hey all, I have a 2000 TJ Sahara with 35s, 4.88s and eaton e lockers, 4" lift with currie springs, metal cloak trackbars, metal cloakdouble adjustable control arms, and currie correctlink tierods and draglink. Most importantly with a Teracon SYE kit and a Tom Woods double cardan driveshaft. I have the proper geometry for a CV driveshaft (0 angle between driveshaft and rear axle). I've been struggling with an oscillating vibration that just seems consitent with improper driveshaft geometry. It is noticable from 40 mph + for like the last 5 or 6 years now. I've toyed again and again with slight adjustments to the control arms thinking maybe the driftshaft to axle angle was +or- 2-3 degrees off or that there is some slight upward motion of the rear diff when accelerating but nothing seems to work. Was toying with the idea of a dropping the transfer case an inch or two to see if that helps but that seems unnecessary considering my setup should be fine. Anyone have any ideas what could be going on here? I've tried much more too. I've exhausted all my options and spent 
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Do I need a 1" drop for my 01 to because of the factory shaft and the front seal on the front of MTV transfer case? I did the rear. I have a 4" lift
I can’t tell you how much of a transfer case drop you’ll need, but I can tell you that you need one for sure for 4 inches of lift. It’s just going to be a matter of experimenting with different heights of transfer case drops to see how much it takes to get vibration free.
Just thinking out loud here, and I’m new to jeeps so don’t flame me too badly, I’m just trying to do some research for getting a lift. So I was thinking rather than dropping the back of the transfer case why don’t you raise the front of the engine? It will produce the same result although eventually you’ll run into a clearance issue, although I don’t know what will hit first.
Yes, a MML will provide some correction to the rear driveline angle. After about 2.5-3” of suspension lift, you need a significant TCase drop or an SYE and DC, the latter being preferable.