Clunk in the rear when taking off

[happy wanderer]

Over the last 12 months our 2013 (5 Spd) WK2 has developed a 'small' clunk. The clunk is coming from behind me.

Car has only 48000km on clock but out of warranty. We are in Sydney.

Clunk only occurs after taking off from a complete stop. It is barely noticable when driving around the 'burbs, but when towing our camper trailer (1300kg) it is far more distinct.

It does not occur on every take off, maybe 50% of the time and maybe 80% of the time when towing the camper.

In 6 weeks we are heading off from Sydney to Mungo, Flinders, Oodnadatta, Katherine, Gibb River Rd,Broome, Tanami, Alice Springs - then see how we are going.

I've developed severe paronia about the clunk with the upcoming trip. Took it to regular mechanic who has always serviced it. Said its nothing, just dropping into gear properly as taking off.

Had the auto transmission serviced by a 'specialist' as part of the trip prep and mentioned the clunk. He thought it could be front and rear diffs running at slightly different speeds and might need a software 'update' from the dealer.

Then phoned Stu M. Stu has done suspension, exhaust and remap, so need to discuss whether dealer 'update' may effect remap. Stu thought from the description it sounded like driveshaft bearing - repair $2500 and going up from there. But only going off my description as we are 1000km away.

Phoned Jeep 'Customer Care', but as its no longer under warranty had to talk to dealer about any 'goodwill' warranty repair. I phoned dealer and waiting for a call back. Never had it serviced there so not expecting any help.

Has anyone had this problem ? What was the problem, repair bill and where was it done ?

Thanks for any thoughts, as I say just paranoid the thing may go bang at the worst time, towing trailer half way to Wolf Creek

[skipperau]

While I don’t have a WK, there are a few basic faults that could cause a clunk in the drivetrain, in order of likelihood, worn suspension bushes, worn shocks or shock mounts, worn uni joints, excess play in the diff, collapsed driveshaft bearing. Things start getting progressively rarer from there. In Jeeps you could probably concentrate on the first 3 in your initial search.


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[08crd]

Adding to what skipperau has said, it definitely sounds like a bush or mount is breaking down.
I would be looking at all the rear end bushes, trailing arms etc, then work forward.
Gearbox mounts, engine mounts, front diff and suspension bushes.
Then go to uni's.
Skipperau has covered them all, but I would suggest using a least expensive first approach.
If it is more noticeable when towing, check the towbar mounting bolts, including the towball.

[happy wanderer]

Thanks guys (and gals ?)

Pretty sure its not towbar/ball, that was my first thought. When I first noticed it I was towing and checked all mounting bolts. Only after that did notice in normal driving.

If it was suspension related, would it make the noise at other times other than take off ? Sorry not very good mechanically....

I need to get a pretrip service so will ask our regular guy to check all the mountings and bushes as part of the service, as well as some of the other lines of thought here....

[Ryan.b]

Have a look through the service bulletins for the rear suspension. They had problems with the rear damper mountings which could be very noisey. This was on the steel spring models with self levelling dampers.

http://www.wk2jeeps.com/wk2_tsb.htm#RSUSPENSION

[skipperau]

Originally Posted by happy wanderer

If it was suspension related, would it make the noise at other times other than take off ? Sorry not very good mechanically....


Not necessarily, there are several combinations of worn bits that will lead to noise on takeoff but not any other time, a worn upper control arm bush for example, it will allow rotation of the diff while starting off, giving a clunk as the bolt slams up against the mount but quiet the rest of the time as it’s under load and stationary in relation to the mount. This is consistent with the early stages of a premature failure of a single mount, or a couple of mounts. The best way to check is to raise the vehicle on a 2 post hoist so that the suspension is hanging in the air, get a lever such as a long screwdriver or pry bar and lever each control arm mount and I’d be willing to put money on you finding one or more with an abnormally large amount of play in them. If you get on well with your mechanic get him to show you how it’s done as he goes through them. You’re looking for no more than say 3mm or so of movement. Any more than that and it’s worn. Also look at the bush itself for cracking, splits, or ovaling of the holes. Surface cracks are normal as part of the normal wear and tear process but deep ones are a sign of them breaking down.

I need to get a pretrip service so will ask our regular guy to check all the mountings and bushes as part of the service, as well as some of the other lines of thought here....

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[happy wanderer]

Great advice, thanks Skipperau. Booked in for service next week and will ask them to check this. Hopefully I'll get a look whilst up on the hoist.