TexasXJ

Hey guys, I am new to the forum and fairly new to the Jeep world. Anyway, I have a 95 XJ with Auto trans and NP231 TC. 175k miles. To start I am getting the usual clunk when I accelerate and decelerate. On top of that I am getting a vibration above 40 mph only at light throttle. When I push the pedal a little harder it goes away. The vibration is slowly getting worse. I removed the prop shaft and test drove it and it still does it.

I have installed quadratec heavy duty leafs, and RE 3/4' lift spacers.

I have replaced the:
- All motor mounts
- Rear U-joints
- control arm bushings
- shocks

I also tow a 15'6" bass boat at least once a week. I am assuming this has something to do with the TC finally going out from towing the boat. I have tried greasing the slip yoke with no luck. I am guessing maybe a bearing in the TC or possibly the chain stretching is causing this. Any Ideas?

Thanks,
TexasXJ

rodknocker

Did you check all of the u-joints when you replaced,it sounds to me like a u-joint issue.

x91j

where do you feel the vibration?

98xjcrawler

X2 on the u joints, also you said you replaced all motor mounts but have you checked the tranny mount?

TexasXJ

Yes, replaced transmission mount as well. I feel the vibration in the rear not in the steering wheel. I removed the driveshaft last night and the U joints still feel solid.

How possible is it that the slip yoke could be wearing out?

x91j

no way!? ok well ill put my thead in here and show u what ive come up with. im having the same problem

x91j

https://www.cherokeeforum.com/f2/still-shaking-35052/
there you go. read up

TexasXJ

thanks. I will get out there tonight and try tightening up the U bolts on the leaf springs. I will update with new findings.

98xjcrawler

I dont know how accurate of a check on the u joints you can do with the driveshaft removed, most times people check with it in vehicle, try to move driveshaft side to side of joint, ANY movement is indication of a bad joint, only other thing I can think of is you may want to pull diff cover and look at gears, my 98 xj with fact. trac loc unit chewed the ends of the spider gears and would cause vibration while coasting and slight throttle, which usually went away with a little more gas

TexasXJ

Forgot to mention I have changed the fluids in both diffs. Didn't notice many metal shavings if any.

x91j

i havnt drove without the DS yet but i did tighten up everything and it go a little better

TexasXJ

I installed a RE 3/4 TC drop kit today and it fixed the vibration that I had at light throttle but i still have the clunk when I accelerate/decelerate I am thinking that is probably play in the rear diff. If that gets any worse I will take it to the local drivetrain shop in town since I don't want to get involved in messing with the gears. Thanks for all your input!

x91j

try driving with out the rear DS see if it goes away

TexasXJ

Won't all the TC fluid come out?

x91j

some one told me to cut the top off a pop bottle and tape it around the whole so u dont use tc fluid