SUGGESTIONS? Grinding sound from the rear

[Audiobahn77]

Ok, I'm in Iceland so mechanics are crazy expensive....I have a grinding sound coming from the rear when I drive. It only does it while driving and it doesn't matter what speed I going. What is the easiest thing to check or if you all know what it most likely is? It's a 97 JGC Laredo with 78k. I'm guessing a wheel bearing, but don't know how to check and I don't want to have to keep playing the guessing game if I don't have to. I have to change all my rotors anyways, so if I can knock it out at the same time, that would awesome. My vehicle mechanic skill knowledge is crap, but I can tell you how to work on a multi-million dollar aircraft. Go figure!

Thanks,
Audiobahn77

[dksob81]

1st check the fluid level in the rear differential. u might be low on fluid.

I would just change the fluid, it is prolly time anyways.
and when doing so make sure u pay close attention to the old fluid look for metal shavings, and check out the Ring and Pinion gears make sure none of the teeth are chipped.

[xj31]

if its an aluminum dana 44 axle it probably needs carrier bearings.I don't know about Iceland but in the U.S.,if it has a V8,it has the aluminum 44

[dksob81]

xj is that the 97 models (that has the aluminum D44 rear axle), my 94 ZJ 5.2L has a D35

[xj31]

96-98 v8s had the aluminum 44.wjs with v8s or 6 cyl quadra drive also have it.93-95 was 35 only

[dksob81]

ok just checking. was thinking it was an added options on the V8 ZJ. thanx for clearing that up

[Audiobahn77]

I do know that I haven't changed the diff. fluid since I bought it back in 2000. I've only put on 38k since then. I was reading in another thread that you need to put in some kind of friction modifier of some sort when you change the fluids? What kind of fluid(s) do you recommend? My JGC is a 4.0 I6. I don't know how to tell what kind it is, but hopefully you all can. Some one at my work mention that maybe a brake maybe dragging? Is that a possiblity?

[Cam7]

Mine is a 96 5.2 with a 35. If Iam right the 44 was optional in 96? As far as checking try jacking up the rear and spinning the diff see if you can locate the source esp if you are changing fluid its easier with the access cover off.

[Audiobahn77]

ok...I jacked it up and spun the rear wheels by hand and it was silent. I even put it into 1st gear and it was silent. So it only grinds when there is weight on the wheels. Which leads me to believe the wheel bearings. The rear diff is a Dana 44 and the fluid was full, but had some moisture in it. I'm going to change it out for some fresh fluid because it's time to anyways. I'm going to look at the bearings next as I change out my rotors on Friday.