Hi there,

I have a 2000 XJ 4.0 auto which has 78000 miles on the clock. My jeep has a Dana 35 rear diff, a 242 transfer box and solid prop shaft, without a slip joint.

I have a couple of noises coming from the transmission/ rear end, but I am unable to confirm which. There is a general bearing rumble once the car has done a few miles and everything warms up. Also when the car comes to a complete stop after it has been at speed for some time, there is a loud clunk clunk cluck, when it pulls away again.

I have been under the car with the rear wheels off the ground and there is no play in the u joints. There is a bit of slop in the output shaft from the transfer case but it doesn't seem excessive. The rear axle and wheels turn freely with a small amount of backlash.

The noises do appear to be coming from either the diff of the transfer box but I am at a loss which one is the likely culprit and where to start.

Does anyone have any experience of similar occurrences, or thoughts on what the likely cause is?

Many thanks

 

I have the same problem with the exact same Jeep. I thought diff lock was stuck on but found out they don't have one just a limited slip dif. I also checked my UJ's and they seem really tight and solid. Took a mechanic friend out today to see what he thought and it didn't make the noise.
I maybe hadn't driven it enough though as like you mine did it after about 10miles at 40mph average, when everything was warm. Maybe the UJ's are getting warm and then binding.

Lets hope someone can help with it.

Also from the UK

 

Hi,

It certainly does sound as though we have a similar problem.

I can potter around town all day long and the clunking noise doesn't show up, but after 3 or 4 miles at speed it's back, when I stop and pull away again. The rumbling noise does come in a lot sooner though after just a few miles, regardless of speed, so I'm inclined to thing there may be 2 unrelated issues.

As I said, I put the thing up on axle stands and went over the driveline the other day. There is bit of notchiness when you hold the rear wheel and rock the propshaft, but its hard to tell if this is causing the clunk or not. The rear wheel bearings don't feel loose up and down/side to side. There's some movement in and out, but I understand thats normal and just slack in the C clips in the diff. There is also a bit of play in the output shaft from the transfer box but I don't know if this is normal?

Both faults have been with the car for some time now. I'd first though the rumble was a front wheel bearing, but those have now been replaced. It is difficult to identify exactly where the noise is coming from which makes it harder to diagnose.

I went to a specialist 4x4 garage and the guy (who didn't seem overly interested) went forward and reverse a number of time, then commented there was a lot of slack in the driveline. He said he'd do some research and come back to me, but I got the impression he was more interested in servicing landrovers than trying to resolve a jeep issue.

I'd be very grateful if anyone does have any ideas? I don't want to start just throwing money at the problem, so I'm at a loss to know where to start.

Many thanks

 

After sleeping on it I have decided to replace the prop shaft u joints. They do feel firm, but this will be a cheap job and will at least eliminate one possible cause.

 

P.S. Any advice on this issue would be greatly appreciated!

 

keep old ones as spares if still good

 

I am taking the Jeep out later today for a good run pulling a heavy trailer so will get back to you if the noise comes back again.
Good luck with the UJ, like you say its not too expensive and lets face it they are really easy to work on being so high up. Let us know how it goes

 

Did you change the UJs yet?

When you turn the back wheels when jacked up, is it quite hard to turn the wheels. Mine was! The prop shaft was not turning just the diff. Box was in Park hand brake off. Easy to turn the first inch or so then when gears are working its quite hard to turn and would never spin when released.
Mine is still making the noise but only when pulling away, its really smooth and quiet after that, had it up to 80mph yesterday and it ran lovely, no wobbles and very quiet.

 

Hi, I have ordered the parts & waiting for them to arrive.

My rear axle turned easily. You need to have the gear selector in neutral though, or the driveline will be locked up.

I had a transmission guy look at my car and he felt the UJ's are the likely cause. He said they may not be loose but can just be notchy, which will create the problem.

I will be swapping them all next weekend, including front driveshafts & will let you know the outcome.

Best of luck

 

X2, nothing worse then blowing the caps out and not having spares.

 

After going over everything I found the front right (drivers side) axle UJ is totally wrecked. I knew it wasn't good and I thought the noise was coming from the rear. Anyway I have ordered a new UJ and the 13mm Bi-Hex 12 point socket to remove the hub. Should have it done by the end of the week as I am letting those bolts soak for a day or two.
Hopefully it was that making the noise!

Will report back when its done.

By the way my disc (rotor in US) was really siezed on the hub. I had to bash it hard for about 1/2hr before it came free. Got the pressure washer in there to cleand up the area before soaking it in derv.

 

I had the same problem when a changed my hubs and discs. Removing the hub took some doing also. The bolts came out easy, but I ended up using a Hilti hammer drill and chisel to get the old discs and hubs off.

It's good to have found the issue! Best of luck!

 

For seized parts, I swear by PB blaster.

 

So does everyone else in the US, can't get that in the UK.

I have always used Diesel in a used kitchen cleaner spray gun. Works really well too, especially if combined with lots of heat and its mega cheap.

 

Changed the front UJ and still makes the noise after about 10miles.

I think its either a prop shaft UJ or rear diff issue.

I am also wondering if it might be a lack of additive in the rear diff.

Anyone know the symptoms of this?