Transfer Case Drop Question...To drop or not to drop?

dswi · 07-23-2009, 09:24 PM

91 YJ, 2" body lift, Stock Leaf springs, raised shackles (yes, I know they are bad on springs!), I did a transfer case drop this morning...lowered it about 2" evenly with 6 spacers and new bolts/washers.

On the actual T/C drops, are all spacers the same or are they larger in the front and smaller in the back?

I haven't driven it since the T/C drop, but I am trying to eliminate a vibration to do with the drive train around 50-55 mph...

Should I keep this even T/C drop in place or take it out?

By the way, I also have a broken driver side motor mount that is being replaced by me tomorrow morning.

Thanks for the input

provinT13 · 07-23-2009, 10:03 PM

How big are those shackles? You shouldn't be getting vibes with stock suspension and some shackles. It may be a different problem with worn u joints or something of that nature.

**johnboy68** · 07-23-2009, 10:04 PM

The TCase drop kit that came with my lift consists of two 2X2 square tubes the length of the skid (one for each side) with pre-drilled holes. They are not tapered.

dswi · 07-23-2009, 10:16 PM

Quote:

Originally Posted by provinT13

How big are those shackles? You shouldn't be getting vibes with stock suspension and some shackles. It may be a different problem with worn u joints or something of that nature.

Shackles are probably about 6" center of bolt to center of bolt.

U-joints seem tight (when hand shaking/pulling)

If i "get off of the gas" when the vibration occurs it goes away (I am thinking that this means that it is not to do with the tires/balancing.)

Doesn't matter the gear 4/5 it occurs at about the same speed.

What is the worst that can happen if I leave the T/C drop in?
It does seem to straighten the rear driveshaft a little.
I have not driven it since the drop that I did this morning.

Jeep is at work now...I will see it again in the morning.

dswi · 07-24-2009, 05:41 AM

Here are some pics if it helps any...

TSEJEEPERS · 07-24-2009, 09:01 AM

Just leave it for now. You said you have a broken motor mount. That may be what is causing your vibes.
You may also want to check you transmission mount.

**Louie4** · 07-24-2009, 10:07 AM

I don't think there should be much vibration with your set up there. The shackles are 2" longer than stock so you're getting about 1" of lift there, but I wouldn't think it would cause too much vibration, especially if you drop the t-case. If I were you, I would try swapping the wheels around (cheap way to diagnose) and check the transmission mount as said above and the stabilizer bushing on the drivers side of the tranny. See how the motor mount helps too.

dswi · 07-24-2009, 11:38 AM

OK, I have removed the transfer case drop...Didn't even crank it up with the T/C drop in place!!
Noticed (thank you TSEJEEPERS) that the Transmission mount is also cracked...The Transmission stabilizer....Should that be bolted to the bottom steel plate??
It isn't.

Thanks again Jeep Forum for saving the day with much needed information.

provinT13 · 07-24-2009, 12:57 PM

Yes it should be bolted to your t-case skid plate

J-Quad · 07-24-2009, 01:22 PM

Quote:

Originally Posted by dswi

OK, I have removed the transfer case drop...Didn't even crank it up with the T/C drop in place!!
Noticed (thank you TSEJEEPERS) that the Transmission mount is also cracked...The Transmission stabilizer....Should that be bolted to the bottom steel plate??
It isn't.

Thanks again Jeep Forum for saving the day with much needed information.

dswi,
How about posting a pic of your transmission stabilizer 'being bad'?

J-Quad

dswi · 07-24-2009, 01:57 PM

Quote:

Originally Posted by J-Quad

dswi,
How about posting a pic of your transmission stabilizer 'being bad'?

J-Quad

There should be a nut on the bottom of this...Correct??

Sorry for the horrible picture. I don't think that the rubber on this is actually broken...but I do know that the transmission mount has a visible crack in it.
I am hesitant to replace it before determining the actual problem (what caused it to crack...besides 18 years of force...and a NON-MECHANICALLY INCLINED PO having the Jeep since 1997!)

Vibration still exists...BTW.

**Louie4** · 07-24-2009, 03:33 PM

Man, you're lucky on the stabilizer stud. The nut on mine was gone and it took the threads with it. If I were to guess, I'd say the transmission mount got oil soaked, expanded and deteriorated. Either way it sounds like you need to replace the trans mount. I would do that then see what happens. Plus put a nut and a big washer on that stud. It keeps the tranny from rotating when taking off.