97 P38 "Clanking" noise under acceleration
 

Hello all,
I have a 1997 Range Rover 4.6HSE I purchased a little over a year ago. I noticed it would make a noise under extreme load when I first got it. It's a "Clanking sound" like a gear slipping on hard acceleration. Here is what I know.
It does it in forward or reverse gears.
If you accelerate "lightly" you can allow it not to do it at all, but that is getting harder and harder.
If you jack it up so all 4 wheels are in the air and put it in gear, all 4 wheels turn like I would expect.
It shifts smooth and regular.
The sound "seems" to be comming from around the transfer case, but I can't tell for sure.
If you put on the Emergency Brake and bear down on the accelerator pedal it does it.
It is VERY LOUD from the outside.
It has got progressively worse over the year I have owned it but other than making a heck of a noise, doesn't seem to bother anything.
It sounds like a chain or spragg slipping, but if it is, which one would it be?
And last, if you take off from a dead stop at just the right level of acceleration, you can feel the truck kind of loose momentum each time it makes the clanking sound. But you can accelerate very hard and the truck will drive off like there is really no problem, other that the horrible sound.

I have assumed up to this point it is the transfer case and maybe the chain is bad, but everyone tells me that there is no way it would keep driving if that was the case.

I have been a mechanic all my life but Range Rovers are faily new to me. I really hate to say it but the dealerships in town will TOTALLY RAPE YOU if you come in and don't know what to tell them to do. I have found it is WAY better to do the repairs my self if possible, but this one has me stumped.


Any help is appriciated as allways! Thanks for any help in advance.

I can't seem to find anyone who has the chain in the transfer case get loose or fail so I am wondering what type of indication that would give, if anyone cares to share their experience. Thanks again.

I think you may be right about the transfer case. The e brake is located on the back of the TC so I would rule out anything else in the drive train other than the tranny. You may want to drain the gear lube and see what it looks like, that may tell you a lot.

Its probably the chain in the transfer case jumping around one of the gears. I have seen it a few times before.
If you drain any gear lube out of the transfer case, its def shot. It uses ATF and has a pump lubrication system.

What you are describing is definitely a lose TransferCase chain making the noise. They are known to last about 80-90K miles. Just had mine replaced at 87K and RR is now good as new. Rave CD has the whole process on removing the TC and opening it to get to chain. Chain itself is about $400.

Finally, we have a winner!. I have to say thank you SMURTAZA for confirming this for me. On the other hand, now I am afraid. I purchased a used transfer case, strangely enough with exactly 87k on it, and you said you had yours replaced at that point. Man, I would expect the chain to last 150k or so. That really suprises me. The dealer here in Houston goes totally crazy every time I ask for a quote. So I am afraid to take it back for anything. He told me $3,800 to repair my AES. I replaced 1 $4. air line and it has not screwed up in 6 months. So a transfer case job from them would likely cost more than a new RR. Any possible chance you would devulge the cost of having yours repaird? Thanks again,

My Rover has 170K on it and the chain is perfect. I think it is a hit and miss scenario and as always if you service it like you are supposed to it will last longer. With the cost of the just the chain I would buy used TC cases all the time and not replace the chain myself.

Wow, so they can go into the hunderds of thousands of miles if you are lucky. Well, that's good to know. I purchased a used TC off eBay for $400. that is out of a 01 4.6 with 87k. I just couldn't see spending $400 on the chain only to find out the sprokets were stripped too or something. And, the used one has a 6 month warrenty, so hopefully it will work out. Thanks for the info Handsome Rob. Any input is greatly appriciated until I get this thing repaired. My new/used TC should be in any day. Thanks again!

To replace TC chain is about 7 hours labor, I paid $1200 including parts. If you have the TC out, I would change or at least inspect it before installation. The major cost is removing and installing TC.

If you replace just the TC the labor will be far less. Rebuilding it will cost a lot more. If you are a mechanical person and don't mind getting your hands dirty. I would highly recommend pulling out the service manual and rebuilding the TC yourself. It really is a simple mechanism. It will require patience, but will save you a lot in the end. I don't know how long you intend to keep the rover, but replacing the sprockets and chain is the best long term solution.