Vibration In Rear

I just replaced my 2.93 diff with a 3.23 lsd and had to change drive shaft flange and two half shaft flanges. Now when I go between 60-70 if I let off the gas there is a vibration in the rear. Also if I push the clutch in between 60-70 there is a vibration but if I give it gas consistenly then no vibration ( only when clutch in and/or let off gas between 60-70 mph it vibrates ) any Ideas? Could I have over tightened the driveshaft flange when swapped out? Could it just be a coincidence and be my exhaust or something vibrating at this certain speed? Thanks alot

Could be a number of things. Did you follow the rules when you reinstalled the center support bearing and flex disc?

I torqued the input nut and turned the side flanges and they turned easily......whats the rules? I couldnt find anything specific.......just seems like if I did something wrong the diff would grab or vibrate all the time

When I swapped my differential flange from 4 bolt to 6 bolt we just tightened the fcuk outa that 32mm nut...Maybe yours is just still loose?

but if you tighten it too much then you cant hand turn the axle flanges..they get tight/stuck

I'm talking bout the driveshaft flange...isn't that what you're talking bout?

yea but when i tightened that too much then the sides wouldnt turn

Was the car in gear and/or e-brake on? Shhiiit I didn't even check to see if mine turned...lol just tightened and left...

well I tightened it out of the car and tried to spin sides and didnt spin so i losened it till it would spin like did before swapped out

I dont know then...lol...maybe someone else can help...sorry...

haha...thanks for the help

This sounds exactly like when I had a loose wheel, I know it sounds stupid, but check.

On the highway, it would vibrate unless I gave it gas. Only one lug was tight, and one had completely fallen out.

thanks...will check

wheels are tight

Did you jack up the car and wiggle them?

If they're still tight, jack the rear of the car up safely, have a friend *drive it* through different gears and see if you can see the diff moving, or anything else not normal happening.

yea they are tight.....if i over tightened or undertightened the nut on the driveshaft flange would that cause this? just seems weird that its only between 60-70 mph......and fine when on gas....seems like if it was the diff it would happen all the time.....damn this sucks...

Originally Posted by B1MM3R

yea they are tight.....if i over tightened or undertightened the nut on the driveshaft flange would that cause this? just seems weird that its only between 60-70 mph......and fine when on gas....seems like if it was the diff it would happen all the time.....damn this sucks...

When was the last time ur Dif and subframe mounts were changed? I have a similar problem and my bushings and mounts are shot. Rtabs. Too check it all if it's not all new?

Originally Posted by JoshuaG

When was the last time ur Dif and subframe mounts were changed? I have a similar problem and my bushings and mounts are shot. Rtabs. Too check it all if it's not all new?

Just got the diff...only have 95k on it...they looked good when out of car

did you pull your drive shaft apart at the CSB?
if so did you re-install it exactly how it came apart? (they are balanced together)

definitely sounds like a drive shaft issue to me not a diff problem..

the problem you described sounds exactly like what happens when a U-joint starts to go on a truck, , vibrations a certain speeds and when no throttle is applied

(i own a lifted jeep, ask me how i know about driveshaft problems )

Yea a guy at my work said it sounds like a u joint too...just weird that I only noticed it after swapping diffs...did not take out driveshaft for swap

have you replaced you guibo?

Originally Posted by noexceptions325

have you replaced you guibo?

Nope...all I did was swap the Input flange and output flanges on the diff's nothing with the drive shaft

inspect it and see if its cracked and retarded looking

Originally Posted by noexceptions325

inspect it and see if its cracked and retarded looking

Yea im going to tomorrow...just jack up the car and secure it...look around and possibly run in at 60 and see if I see a problem there...ill be back in touch tomorrow...once again I truly appreciate everyones help and input

ok so I still havnt had a chance to check car but ive been google'ing replacing the u joint and some people say that you can't replace it...is this true?