RPA_XJ

Hi gentlemen,
I recently replaced my rear suspension. I put on HD leaf springs, and got new shocks and I was given rear shackles that are about a 2 inch lift in themselves. Now me being a rushing kind of person, I completely forgot to realize that since the back is now around 3.5+", there would be a vibration bc of the angle change.


Would a transfer case drop "kit" be what I am looking for? I read on here that it is just a band-aid and to stay away however I am not using it to go wheeling. This is just a daily driver and using 4WD as needed whenever. The front end is 2". I am stressing out here and any help would be greatly appreciated.


Thank you

Jeep Driver

http://www.customdriveshafts.com/

myjeep

the ujoints wore at the previus ride height now that it is lifted the ujoints are riding inbetween the groovs that the needle bearings made and that givs you a vibration. replace the u joints and check shaft angle and go from there.

thatXJguy

If it's a daily driver, a transfer case drop kit is a perfectly fine solution to get your angles right. It'll wear out your engine and transmission mounts faster, however.

People who offroad are going to tell you to adjust your pinion angle instead, which is hard to do unless you have adjustable control arms.

RPA_XJ

Thanks for the quick responses.


My jeep, the U joints were all replaced before hand, this didn't start until the first ride after the installation.


XJ guy,
I keep trying to find a definite answer online about what size drop I will need. I see some say 1/2" is plenty and others say 1 to 1.5" is what is required. I don't want to go to far with it and really fudge something up.

Alpha 1-4

A couple images that I hope help you out.

RPA_XJ

Thanks for the pictures. I know it is too angled so I have it parked to prevent any damage. Would a 1" drop suffice? I have never used one of these little kits before.

Alpha 1-4

You might be better off finding the difference in Degrees and shimming the axle. T-case drop kits add strain to the motor mounts, which in stock form break down easily already.

Fred/N0AZZ

X2 or an SYE to do it right and never worry about it again.

InitialForce

I run the Rusty's crossmember which gives 1 inch drop on a 4.5 inch lift on the stock driveshaft without vibration but x2 on breaking motor mounts. I had to go to brown dog motor mounts... Haven't had any issues with the trans mount (rustys supplied me a new one when i got my crossmember that is different from the stock design)

SteveMongr

I believe the issues is mostly due to the 2" shackles. They cause the pinion to rotate upwards, then rear u-joint is out of phase with forward joint.
A TC drop, coupled with drop shackles, increases the driveline angle. What is important is that each joint angle is equal so that they are 'in phase', A TC drop can do this but is a band-aid.
The engine is already tilted. Tilt is too much with TC drops and cylinder #1 may starve for oil.

InitialForce

I'm lost, so how are our motors able to survive hill climbs? Everytime i go to tehachipi or LA from Bakersfield I am rolling up hill at high way speeds for 20+ miles continues

kgm

If you are lazy like I was, you can get a slip yoke CV shaft. This allows you to not have to install a SYE which is a little more labor intensive, and I still am vibe-free. You will still have to shim your axle. I went with a Tatton Driveshaft Slip Yoke CV shaft & 4 degree shims on RE 3.5" springs. Your individual needs will be different.

SYE is still the best option.

SteveMongr

Good oil flow is essential for cooling. After that commute, use an IR temperature gun or thermal imager to compare block temperature between #1 and #6.

InitialForce

If I had one i would. Curious now.
Still don't see how the #1 would get starved. Oil is delivered with holes in the crank shaft for the rod bearings which in turn provide oil through the connecting rods to the piston oil skirts and the lifters have channels build into the block for them which both are pressure dependent. Only thing I can see getting starved is the rockers because that's a mist spray coming from the head channels and would gravity tend to run to the back of the motor.