Lower the "T" case or not?

K-B · Jul 3, 2007

On my 97 TJ I installed a 1" body lift, a 1" engine lift and a 4" suspension lift.
Included in the suspension lift are 8 adjustable control arms and a "T" case lowering kit.

I rotated the rear differential to reduce the U-joint angle with the drive shaft
which worked well for the last 3 months, since the angle seemed good I have now removed the "T" case lowering kit to increase my clearance.

I am a experiencing a "mild" vibration that I assume comes from the drive shaft now that the angle is increased (still looks good to me but...)

My question is how much damage am I risking

Next week I'll be at the Nile Trailjam and will put the TJ though its paces but don't want to set myself up for catastrophic failure.

P.S. I installed a junkyard York and can't wait to use my new OBA!!!

the vibration seems mild to me, should I reinstall the T-case lowering kit until I can afford the SYE and longer drive shaft?

crash2 · Jul 3, 2007

What about going with the more 1" taller engine mounts?

tj40ounce · Jul 3, 2007

Personally, I think lowering the transfercase & skid on jeeps looks :rb:

I don't own a jeep, but would do what I could to avoid that mall crawler mod IMO.

Long&Low · Jul 4, 2007

IMHO, anything 4" or more in lift and you should get an SYE. If you raise the engine too much, you are curing the rear driveline angle, but making the front worse.

Not Jobless · Jul 4, 2007

Sye...

Dain Bramage · Jul 4, 2007

Jobless said:
Sye...

i guess its a jeep thing.:scratchhead:

99redtj · Jul 4, 2007

sye and new driveshaft.

skrause · Jul 4, 2007

FordFrk06 said:
i guess its a jeep thing.:scratchhead:

Slip yoke eliminator. Yep, it's a heep thing.

tj40ounce · Jul 4, 2007

skrause said:
Slip yoke eliminator. Yep, it's a heep thing.

It's a Toyota thing too, except that Toyota was smart enough to build their cases with a SYE... :haha:

:stirpot:

skrause · Jul 4, 2007

tj40ounce said:
It's a Toyota thing too, except that Toyota was smart enough to build their cases with a SYE... :haha:

:stirpot:

How so? Toyota never used a slip yoke. You can't eliminate what was never there. :fawkdancesmiley:

Dain Bramage · Jul 4, 2007

are we talking about the yolk that goes directly into the t-case in reference to SYE?

skrause · Jul 4, 2007

FordFrk06 said:
are we talking about the yolk that goes directly into the t-case in reference to SYE?

Yes, the Heep rear output yoke slips in and out of the case instead of having a slip joint in the driveshaft. Eliminating it gains you some extra driveline length and helps solve issues with excessive angles.

KarlVP · Jul 7, 2007

If you want to band aid it for now, you can put the T-case drop on it until you can afford a sye.

You really need the SYE though.

mikeymoto · Jul 13, 2007

I don't think anyone mentioned it...so, I believe the major threat when running your transfer case and differential out of parallel is busting u-joints. Bring spares.

I don't know a lot about TJs but if the rear is standard leafs on/under perches you should also be able to rotate the diff some more, putting it in alignment with the TC, using shims between springs and perches. It's another ghetto bandaid, but could help you until you can fix it right.

crash2 · Jul 13, 2007

mikeymoto said:
I don't think anyone mentioned it...so, I believe the major threat when running your transfer case and differential out of parallel is busting u-joints. Bring spares.

I don't know a lot about TJs but if the rear is standard leafs on/under perches you should also be able to rotate the diff some more, putting it in alignment with the TC, using shims between springs and perches. It's another ghetto bandaid, but could help you until you can fix it right.

PSSSSST- TJ's have coils

GaryTJ · Jul 14, 2007

the key with the stock driveline is to make sure the angle of the motor/trans is the same as the rear pinion. Rotate the pinion angle to match the motor/trans.

There is an eccentric cam kit for the TJ upper control arms (at the diff) to do this.

XtrmTJ · Jul 16, 2007

Lowering the transfer case defeets the purpose of the 4 inch lift. SYE and be done with it. Do it right the first time and move on. SYE ! :awesomework: