I just installed a Aussie in the rear of my '99 w/6.5" of lift. The previous owner installed 3" block, a shim, extra leafs, and a 1.25" shackle. I recently noticed that when accelerating maybe 1/4-1/2 throttle out of the hole I get a horrible grinding noise. Sounds similar to extremely grooved rotors. I can feel it and hear it all over the place. I'm going to be getting rid of the blocks and going w/a full leaf pack. Is this from axle wrap or would the trans mount be more than likely the culprit? The motor mounts are about a year old. I did notice before the locker that if you were to kick it down to first at speed there would be a hard clunk underneath, so again hard to say if its axle wrap or tranny mount related... What do you guys think?

TIA,

Sean

 

what is the drive shaft setup? it could be axle wrap is causing the drive shaft to bottom out and cause the noise you are hearing. try blocking the front wheels and having a friend very carefully give it gas and you watch the rear axle to see whats going on. or use a tree, a big one. i would definitely check all the mounts, trans and motor.

zedpapa

 

If you have the oem diagonal TC skid plate it might be that one, otherwise it is either the exhaust pipe clamp near the right leaf spring or the TC mount.

 

That sounds like classic axle wrap to me. Have someone you trust sit in the Jeep with one foot on the brake and one on the gas. Have them put it drive and give it some gas while holding the brake. From a safe distance to the side of the vehicle, look at the rear axle as they do this and watch how far the pinion moves upward under acceleration. I only had a 1 inch block and shim and my pinion was moving at least 5 inches causing u-joint binding and eventually breakage. I removed the block and shim and the axle wrap was minimized.

 

Its running a full rugged ridge HD SYE and a stock front DS for the rear. Anybody know the height limit on using a stocker front ds in the rear? I ordered a tranny mount today since the motor mounts were replaced last year. I'm positive there's some axle wrap as well. I even think its affecting the locker. This is the third Aussie I've put in(in multiple jeeps)and its doing some goofy things in a turn, something aikin to not enough torque being applied to the pinion cross shaft(and all the gapping is in spec). Which I assume could be caused by the pinion juggling around and not getting all the torque it would if it were stationary. Ill replace the transfer mount and then the leafs and go from there I guess.

 

Could you elaborate a bit more on that? I do have the OEM transfer skid. Are you thinking if the transfer mount is bad it could be hitting it? That would be one hell of a sloppy trans mount.

 

bump

 

LIft the rear of the vehicle up.... then block front wheels so it wont move forward or backward. The shift t-case into nuetral. go under vehicle and rotate driveshaft by hand. it should help you find the issue

 

Check the two tranny mount bolts (18mm). Mine were lose and the TC was hitting the plate.