Knocking from the rear...

[Herman4x4]

Not me, but my NP. I have been out a couple of time recently and have developed a knock in the rear somewhere when turning. It is hard to pin point, I thought it was the right hand side, kids are saying the middle and the Mrs's, not sure. Mainly happens when turning. When driving at over 80kph, there can be a noise that I can best describe as the sound a truck makes when engine braking, and is more prevalent when going round a bend or turning.
The exhaust all looks pretty good, the brakes seem to be clear of mud and all bushes look good as well.
Could it be the drive shaft, or diff? My drive shaft is missing the little rubber boot.
Any ideas will be greatly appreciated as I want to get out on more trips, but am a bit unsure as I do not want something to let go when out on a track somewhere.
Cheers,
Andrew.

[AlloyDesign]

CV joint?
bearings maybe (diff if it's coming from the middle)

[Rich]

Hi,
I lost the rear rubber or ruptured it on a trip to Vic High Country.
Some time later I developed the same thing, a knocking when turning.

MM initially quoted me over $2000 to repair it (the shaft cost $2000) as they reckon you had to replace the whole shaft.

I could not get a second hand one so just got them to clean it out. That did not solve the problem so got a partial job done, part was only $700 + labour to replace but that did not solve the problem, so ended up getting the full thing

So many thousands of dollars later it is fixed.

Not saying you have the same problem but scenario similar. I have an NS so parts were more expensive. Normally the parts should cost a lot less, I hope yours do.

Good luck,

Rich

[Herman4x4]

Thanks for the pointers. I jacked the rear end up tonight and turned each of the back wheels, and the other side turned so I guess the diff is ok??? Interesting the shaft caused a knock. I am going to book it in and see what they say. I don't want to be replacing lots of parts that are not needing replacing. The knock I think is getting worse.
Cheers,
Andrew

[Herman4x4]

G'day Rich,
Is there anyway when looking at the driveshaft that this is causing the problem? Is there exesive movement or something?
Thanks,
Andrew.

[Rich]

G'day Rich,
Is there anyway when looking at the driveshaft that this is causing the problem? Is there exesive movement or something?
Thanks,
Andrew.

Andrew,
There was nothing obvious as had it checked out a number of times before eventually resorting to repairing.

When I first went into MM after damaging the boot they suggested I would need to replace the whole shaft which cost $2000, at that time no knocking was heard. The guy reckoned that you can get by for awhile but eventually it will need to be done. I did not quite believe him and neither did others. I raised the question in this forum and with my mechanic and all agreed that this was probably not required. As it turned out the MM guy was right.

I suspect it will not be as expensive now as there probably are replacement parts.

Have a look at

http://140.99.20.180/forum/showthread.php?t=8366&highlight=Rubber+boot

Unfortunately that was not the end of the story. The knocking started some time later after the initial boot repair , noticeable when going around corners. I probably could have lived with it but as I tow a van and want to go to places out of the way I did not want to take the risk.

I did take it to a number of mechanics who could not resolve it as I had thought it was related to some mods done to my car (eg aux tank installed). I finally found one who diagnosed the problem correctly, then the fun and cost started .

When the problem was found there were a couple of solutions a full shaft or partial shaft option. The partial shaft being a lot less in cost but that did not resolve the problem. I found the part number on the web I think

Sorry I can't help further.

[mmannion]

My drive shaft is missing the little rubber boot.

Andrew I presume you are talking about the rubber boot on the tail shaft(from transfer case to rear diff) not the axle shaft that runs from the diff centre to wheel?

If so I don't know if you are able to buy just the rubber boot and if it's anything like the front tail shaft there will be a type of cv joint in there. Crap will get in there and stuff the joint. The CFRP rear tail shaft is expensive but you should be able to pick one up from the wreckers for a couple of hundred.

Cheers,
Mike.

[OGJON]

I noticed a knocking in my NJ today when turning right I checked it all over several times & couldn't find anything then I decided to flex the vehicle up to see if anything was wrong with the suspension & quickily found the problem was that my swaybar link on the right hand side had pull out through the mount some how with out tearing anything & was hitting the chassis every time I turned.

[Herman4x4]

Thanks for the reply guys. I will have a read through the link. I had another look tonight. As there is nothing to see on the drive shaft from the transmission to the diff, I had a look at the drive shafts from the diff to the back wheels. I checked the wheels and took the hand brake off. I have noticed the right hand side is nice and tight, no side to side movement, but the left hand side one has side to side movement, so maybe it is just that??
Does that sound normal to have movement?
Cheers,
Andrew.

[Rich]

Andrew,
Looks Like I misunderstood what/where your problem was and your situation is different.

Sorry if I scared with the $ it cost me .

I hope your situation turns out OK.


Richard

[Herman4x4]

No worries Richard. It did give me something to think about. The drive shaft from the transmission to the diff is missing the outer rubber boot, but there is a one that is around the shaft on the flange.
The knocking I had also sounded like it was coming from the middle, its hard to pin point when cruising down the freeway.
Cheers,
Andrew.

[green monster]

dont suppose its something simple like your bottle jack in the rear well has come loose?. could be rolling around?.
good luck,

[Herman4x4]

Looks like it is the RHS drive shaft. So will be getting fixed next week.
Thanks for all the tips.
Cheers,
Andrew.

[wazza1965]

Hi Andrew
I have been through the wringer on this the first time I had one go. The first time I had just come back from Frazer Island with no issues. I got home took the trailer off unpacked the car and found when I backed out of the driveway I had a clucking noise coming from the rear which was not there when fully loaded. It was very noticeable under load or especially turning left hand corners. After hearing many different options and trying many different things (I thought initially that it was the diff as the noise is very hard to identify) it turned out to be the drive shaft running from the diff to wheels, outer CV joint. On a close inspection the outer rubber boot had a fine split which allowed sand to enter destroying the outer CV. Replaced the complete shaft from MM $1100.00 later and it was all good.
I have just come back from Double Island and have experienced exactly the same thing again. No noise until the car was unloaded then the clunking started again when turning and under load. The outer boot had once again split. I loaded the car up again as a test and the noise went away. I have a 2? lift in my car which puts the CV?s at a greater angle and more prone to wear. When I loaded the car again as a test the noise went away although with a vibration still there. The CV?s were now quiet and sitting much more parallel to the ground with the suspension loaded. Unload again and the noise comes back.
Just replaced the LH shaft again and the noise has gone.
Sorry all for the long winded post but it was driving me nuts until I got to the bottom of this issue.
All the best
Warren

[Herman4x4]

Gday Warren. Thanks for this info. Sounds exactly like my problem. I went away a couple of weeks ago, and when loaded all was good. It initially sounded like the right hand side, so have replaced that side. Still have the noise so will now do the left hand side this week.
Cheers,
Andrew