I have posted different topics on my D35 Differential and my NP249 Transfer Case issues on this forum, but since I think they are related, I wanted to put them on one. I realized the my VC in my transfer case is not going out, because I only have issues when turning very sharp. I did change the fluid anyway and it was pretty clean.

With my Differential my pinion seal is leaking a little and I did change the axle bearings and seals. When I lokoed inside the case, there were no metal shavings or chipped gears.

Now this issue,, I know there are tons of topics on the whinging or howling with these Jeeps, but mine is very loud. It seems to be affected by the acceleration, if I back off the pedal it changes sound. It gets loud until about 65 and changes a little, but not much. It begins the minute that I go forward, even as low as 5 or 10 mph.

Now, when I am in reverese, I get no noise at all! I wish I could just drive in reverse!

My question is,, how can I determine where it is coming from> some say the pinion bearing, some say the carrier bearings, some say it could be the TC anyway. It sounds like it is defimnately coming from the back, not the front.

I would rather not swap an axle and then find out it is something else. With my symptoms, has anybody else ran into the same issues? The no noise in reverse has to mean something.

Please give me some good advice!

 

Pay repair shop to put your Jeep on lift, run it and use stethoscope to listen.
http://www.harborfreight.com/mechani...ope-41966.html

 

X2. That's how a shop found the source of the noise in the '97 ZJ V8 AWD I had. I watched as one guy was inside working the throttle/ shifter/ and/brakes, and another guy went to each item with the stethoscope, carefully listening, then moving on to the next item.

 

Don't over look the ujoints, they can make noises as you described.

 

Could I put my jeep on 4 jack stands and do it myself? I have one of those stethoscopes.

Also, I don't have u joints, I have cv joints in the front. I have a boot that is torn, but it is not making that familiar clicking sound yet, so I have some time to replace it.

 

He meens the u-joints on your driveshaft.

 

yes just be very carefull

 

I would have to say driveshaft u-joints. You only hear it in drive because the ujoint is only worn on the sufaces where being in drive causes it to impact. While in reverse it doesnt make the noise since the plastic isnt worn. you can check this while laying on the ground. No need for a lift

 

Can they be repaired? How can I tell if they are bad, will they move?

Thanks!

 

There should be play. Grab the driveshaft and where it meets the rear end and push and pull them away from eachother. Make sure to do this in more than one spot, basically check it turn it 90 degrees and then check it again until you have checked it all around. You may have to move your jeep a few inches so you can check it fully. And also try turning the driveshaft back and forth by hand while holding the other side still and see if you can feel any play when turning it.

 

none of my biz but no way would i lay under youre vehicle with jackstands and have the wheels spinning. and im sure there are lots of people who have done it but to me it just dosent sound like a great idea. at least on a lift if it slips off the lift pads its still got the arms of the lift to catch it

 

Thats true. To check driveshaft ujoint you can use your hands while its on the ground with the engine off. Theres really no other way to check it besides driving it. In that case it has to be really bad or the tech is really good.

 

I agree guys about checking the driveshaft while engine off and on the ground. I would like to use a stethescope to listen to the TC and the Differencial as well, but I don't have a lift, so I might have too see what a garage would charge me to lift it up for me.

Thanks!

 

Unfortunatly, there aren't many places around that will let a customer stand under a vehicle while it's on a lift because of liability. They'll be happy to do the work and charge you for it, but not with you under it. Some won't even let you in the work bay! Look for an old guy in a small garage who is a classic car nut. They are the easiest to work with.

And when you check your u-joints, make sure it's out of Park. Driveshaft U-joints are cheap and easy to replace, so why not go there first.

 

If the pinion seal was leaking on D-30 front axle, the pinion bearing may be shot. Our '98 GC did this, $400 for a used front axle cured it.