Btommy

ok here is my long and sorted tale.
I installed a 2in lift
got vibes
replace u-joints
did t-case drop (vibes kind of went away)
rear springs bent back wards (vibes return)
added 2 " AAL springs and put stock shackles back in removed t-case drop (now rides perfectly level) still vibes a little but livable.
now i have slack in my drive line, when i pull up to a stop sign and stop it "slaps" then when I take of it "slaps" its like its running slack out of drive-line? it gets worse the warmer it gets. when cold it does not really do it.
it also makes a dieseling sound when I am driving and I let off the gas, goes away when i hit the gas again. (I am thinking rear u-joint is bad from all of drive line moving)
I can grab the drive-shaft and turn it a little bit but nothing real bad.
I know I need to shim my rear axle to get the right pinion angle. could it be as simple as that or is something else wrong?
the slapping is getting pretty bad.
any thoughts?

Rere1992

With 2 inches of lift, you shouldn't need a t case drop let alone shim the axle. The vibes are bad u joints. If there's any play in the joint, then it's bad and it probably wore out from the increased pinion angle.

The t case drop kind of defeats the purpose of the lift because your belly is lower to bottoming out now. My friends got a 3 inch loft and he' fine. Check your front driveshaft too because when I was stock, my front driveshaft was destroyed and vibrated all the time

DoWork25

not trying to thread jack or anything but I also am having that "slap" issue that you are having. not all of the time but sometimes, usually after it warms up, leaving a stop light or stop sign it will make that slap sound and to me it almost seems like the transfer case chain is loose? i am not positive and would like to know for sure before i take the time to do that. my other thought was the rear end but it doesnt do it all the time so i was theoretically ruling that out. if anyone else has any info like this im sure we both would appreciate it.

jrm_2011

Its been a year and 15000 mile since the 2in lift now my jeep only vibs down the highway at 65. I have had the tires balanced and rotated it still dose it is there a sure fire way to check if the driveshaft is bad?

Rere1992

You can take the drive shaft out and play with the u joints. If they're hard to swivel and if there's play in the caps, them you should replace them. When I say play in the caps, the joint should be tight inside the shaft and should just allow swivel movements.

Rere1992

Is it like a clunking or unloading feeling where the rear end drops ?

dogger15

Sounds like t case chain slapping

Btommy

For me it sounds like the rear end unloading (that sounds like a good description even though I am not sure what that means) It almost feels like a something is comming loose but i checked all bolts to see if they are tight. the local gear shop said they will rebuild my whole rearend for 650 bucks (with me pulling and reinstalling) the odd part is it gets worse when it heats up.

Rere1992

My stock Cherokee did that and I never found out what it was but I was fairly certain it was either my brakes letting go because my drums suck or it was the leaf and shackle bushings being seized . That's my .02$.

77olds

The slip yoke likes to stick on these. It's the part of your drive shaft hidden in the rubber boot. When you take off, the slip yoke slides apart just a bit, and because it likes to stuck, you get that "thud" or "clunk" feeling, almost a feeling like there's a bowling ball in your cargo area that just rolled back and hit the lift gate or something.

I lubed mine up and it stopped doing it.

Now it's doing it again. Need to lube it again.

cookrw

How do you go about lubing the slip yoke?

DieselD

I think you might be feeling the drum brakes. I got the same thing in my 91 even after rebuilding the whole brake system (everything new on the rear). I then rebuilt the rear drive shaft, new joints cleaned and greased, refilled tcase fluid and new shaft seal. I was at 4" lift so sye or tcase drop. I still have it. I've read that it is the drum brakes, but haven't found and explanation why... maybe its the adjuster adjusting?

DoWork25

actually its a little of both... my rear breaks need attention because wgen i let off the pedal it kind of drops down in the rear. but then also as soon as i step on the gas i get the clunking sound and like he says some slack in the driveline.. to me it seems like the tcase chain is loose or something.. i have almost 180,000 miles but just got the jeep like 3,000 miles ago. i figured i would just drive it till something broke unless i can figure it out ahead of time.

77olds

You have to unclamp that rubber boot. It has those annoying band clamps that lock together, they're kinda tricky to undo, and I had my XJ on a hoist when I did it.

Then you just slip it out of the way, stick your hand in a tub of axle grease and goop some on the slip yoke, making sure to get it in the splines really good.

Then you just reclamp the boot. And yes, you DO want to keep the boot, otherwise you can expect to be greasing it every couple of days, or constantly having to clean it if you drive anywhere where they're dirt.

pitchblack98

try spending 30 or 40 bucks for an alignment. mine had the death wobble and it was gone after that.