So my rear dif had a leak several months back and I replaced the gasket and changed the oil in it (Mobil syn). A couple of days later I went and had a set of 31's put on (stock suspension) they fit fine and didn't really scrub but after about a week I started hearing what sounded like rub in the back when turning... That's the best way to describe the sound, like heavy tread rubbing/thumping against something solid. I checked around and couldn't find anything and kinda brushed it off cause it wasn't that bad and only happened occasionally. Well a couple weeks ago I went and had a set of 235/75's put on and discovered that the sound wasn't from the larger tires! It's coming from the rear end and is there every time I take off while turning Any ideas?? One guy asked me if I put the additive in for the limited slip? Could this be the cause? I didn't, but I haven't in past maintenance and have had no trouble.... 'til now Thanks!

 

First you need to make sure whether or not you even have the limited slip rear end. I am sure someone will chime in who knows for sure but I don't think the 35's came with limited slips only the 8.25's did.....either way if you did have one and forgot the additive I don't think you would be going anywhere because the clutches would be shot. Don't think this would make the noise you are hearing.

I would check the pinion, grab a hold of it and see if there is any play in it this could indicate bad pinion bearings. Also check u-joints. When u-joints start to go bad they can roar as well as cause bad vibes. When you drained the oil what did it look like? Was there enough? Did you inspect the gears?

 

about the part of the dana35 being non lsd.... there were dana35's with lsd but only on the upcountry package,idk about other years but my 91 has the upcountry and i have a lsd

 

The oil looked fine when I changed it, It wasn't that old, maybe 6 months. The level was fine maybe a touch low but nothing to cause alarm. I did a visual inspection and all looked good. I guess I'll pull it apart this weekend and have a more thorough look...

 

Mine's a '93 country with the towing package. Don't know if that helps any...

 

most lsd's came with a sticker in the glovebox, or u could pull the cover and look

 

here a link thatll tell u everythin about ur jeep,but u gotta fill out sum stuff and theyll email u,and this way itll tell u if u have the upcountry package or not
http://www.jeep.com/wccsapp/universa...ull&category=U

 

First off, a big thanks to you guys for all the help and quick responses! It's truly the members that make a good forum great

Anyway, just checked the glove box and I do have limited slip. So I guess tomorrow I'll run by and pick up the additive and hope it's not too late!

 

hopefully itll be fixed,post it if its fixes it

 

will do!

 

if you have a lsd rear and didn't put posi additive in they can make noise and being that you have a tow package you may have a lsd there may have been a tag on the rear that would say :use limited slip diff lube only: but easy way to tell is by looking at the carrier an open will have 4 spider gears and a pin in the middle that are easily seen... a lsd will be very tight and hard see into and should have clutch packs on either side

 

well i was late to the party....lsd additive makes the posi slip MORE so it is highly unlikely you hurt anything you should be fine

 

Better late then never Thanks for your input!!

 

D35's came with LSD's. My 00 had it originally from factory. If you put the wrong fluid in the rear you can damage the lsd. It needs to slip and if you don't have the right additive to make it slip right it can damage the clutches and cause it to stop functioning properly.

 

I knew someone would chime in about the the 35 being an lsd or not.

As for the noise, I would imagine if the gears or bearings were going bad there would be metal in the oil.