Rear end roaring/hard vibration

Okay, so first off it's a 99 2wd 4.0 Limited.
Dana 35 rear

I know to determine the actual issue, I gotta pull the diff cover and such, but I was wondering what to look for.
Symptoms: roaring/rough vibration from rear of vehicle only when there is power applied to the rear wheels ( on the gas). Off the gas everything goes quiet.
Checked u joints on drive shaft.

Any other suggestions???

If the pinion seal is leaking that is a sign the pinion bearings may be loose. Grab the pinion yoke and try to move it sideways, I kind of slap it with the palm of my hand and try to feel any play or listen for clicking.
Most of the problems I've had with the D-35 was the carrier bearings. Things seemed to get louder in reverse.
I check mine by prying up on the carrier with a tire spoon (crow bar). You can usually feel and see the movement if the bearings are way loose.
The wheel bearing check is pretty easy, you take the drum off and try to move the axle left and right, check the seal for seepage. The axle will move a bit in and out, which never hurt anything I've ever noticed, but side play needs to be minimal.
Empty the oil into a clean pan, strain it and see whats in there.
I usually wash out the inside of the diff out with a can of brake cleaner, so I can check the gear teeth out and do an inspection.

Spawn 93 said:

Okay, so first off it's a 99 2wd 4.0 Limited.
Dana 35 rear

I know to determine the actual issue, I gotta pull the diff cover and such, but I was wondering what to look for.
Symptoms: roaring/rough vibration from rear of vehicle only when there is power applied to the rear wheels ( on the gas). Off the gas everything goes quiet.
Checked u joints on drive shaft.

Any other suggestions???

Click to expand...

You didn't indicate your mileage, but the Dana 35 is known to wear out carrier/pinnion bearings early. With proper maintenance, in a better axle, these bearing should last the life of the vehicle.

Mine, at about 115K were shot. The axle was noisy like yours. I replaced the carrier/pinnion/wheel bearings and seals and now it's as quiet as new. Before you do it I'd check the contact pattern on the ring gear first, just to eliminate excessive wear between the pinnion and ring gears.

Well, mileage is 217k.

New symptom: when I am coming to a stop at a light or a stop sign, it makes a loud clunk like something is loose or rolling around in there. I am going to pull the diff cover later and see what I see........…

That clunk from the back could mean a bad U joint, could mean wear between the ring gear and pinion or could mean a bad bearing. I've had differentials that were set up loose new and had a clunk for 200,000 miles, might mean nothing.

I would follow 8Mud's diagnostic tips for the bearings. I've had bad bearings on several axles I've used, most were JY axles that I swapped into the jeep (HP30/8.8) but my old 8.25 had a bad axle bearing too though once. I usually just pull the carrier & shafts though to get a good look at everything, nothing better than "seeing" things like this up close to know for sure one way or the other.

First post made me think it could be a limited slip running without the friction modifier...but now the clunk is not inline with that diagnosis.

I will update ya'll after I pull it apart later. Thanks for all of the good input and ideas!!!!

Just a little update on this one, I guess when I checked the ujoints the other day, I couldn't feel the rear one was loose...... Blew up on me while trying to accelerate from a rolling stop. Needless to say, I will be replacing that in the morning.