driveaxle/CV joint issue

[moribundman]

I hear an RPM-dependant, rythmic clonking noise emanating from the right front wheel area when coasting at about 2000 RPM. Is it normal to feel a little play in the CV joint when grabbing the driveaxle, or mustn't there be any noticeable play?

 

[Gurkha]

Any kind of clunking noise is a sign of worn down joints, have you been greasing them regularly by the way.

 

[moribundman]

The inner and outer CV joints are sealed and cannot and shouldn't, even if it were possible, be greased without removing the boots, which in turn requires removal of the driveaxle.

I simply don't know if a driveaxle may have ANY play. I don't want to replace the inner and out CV joints, or possibly the whole drive axle assembly without making reasonably sure the noise I hear isn't caused by something else. I suppose it could be the wheel bearing.

 

[kenw]

ditto...

how does one go about "greasing CVs regularly"??? About half a million FWD miles under my belt and this is one thing I've never, ever done unless the CV or boot failed to begin with....

You can replace the boots without removing the axle by using a split boot, have done it a few times when the boot failed (split) and I found it before the CV got filled with crud. The new boot comes with a CV grease to replenish.

usually a bad CV is noted by making a slow turn at max turn of the steering wheel, sometimes while backing. It usually is one clunk per rotation of the front wheel. Personally I've never had a CV fail without the boot splitting first. If your boot is split, and appears to have been split for some time, AND you hear the clunking noise....it is a safe bet to assume the CV is toast. Often (but not always) you can feel the clunk in the steering wheel.

The drive axle may have a bit of end-to-end play and be fine. Or not, depending on the type of car. I don't think it's an indicator of a worn CV.

BTW, new CVs run $150-200 US per side, including labor. More at a dealership usually. Much more...

 

[moribundman]

Greasing a CV joint would be difficult, as an exactly measured amount of grease is required. Anyway, the boots are not split, but at 9 years old there may be hairline cracks and it's quite possible that moisture did get inside the joint(s), causing corrosion and wear. The right front driveaxle has more play then the left one, and that's my main indication that a worn CV joint is the problem. While replacing the whole driveaxle with inner and outer CV joints isn't difficult at all, it may be difficult for me to disassemble the driveaxle due to a lack of tools. One CV joint is pressed onto the axle, and according to my repair manual, at least one special tool is required.

There's no "click" in turns, only when coasting at certain RPM.

 

[kenw]

be aware that the CV "bearing" is available pre-installed on an axle.

 

[moribundman]

Yeah, I am aware that I can get the complete driveaxle assembly with inner and outer CV joint pressed onto the axle. At 133k miles old, it's probably better to simply replace the whole part and turn the core in for some credit. There are two different styles CV joint available for my car. Unless I remove the axle, I won't know which one I need. One CV joint contains a roller bearing cage with 6 balls, the other one contains three rollers. It's a joint, it's a bearing, it's everything at once. It's like 200 bucks. ;-)

 

[Gurkha]

On my MB G Wagen, the recommended interval for greasing is 60,000Km, sooner if it has been used for wading, I do mine at 30,000Km and my axle is still noiseless at 175000Km, it is truly a pain in the neck job, takes and entire day, the joints have balls for bearing which have to be set up carefully or there goes your US$2200 joints.

 

[moribundman]

Do you have the older, utilitarian version of the Mercedes G(eländewagen), or the new one with the plush interior? I'm sure you know this, but the Mercedes G is made by the Austrian company Steyr (actually Steyr-Puch). The car is also available as "Puch G" in some countries.

[ February 01, 2005, 07:24 AM: Message edited by: moribundman ]

 

[Gurkha]

I now have the Gurkha which is the Indian made G made by Tempo/MB subsidiary here. It uses IFS in the front with CV joints, I also had a G-240 till last year when I sold it, this was the one with the high mileage. My G is totally utility with all metal interior, nothing plush, comes with OM 616turbo, ZF 5 speed tranny, Steyr Puch transfer case as well as diffs. It has diff locks on both wheels as well as 16" wheels along with a PTO. Comes with a tubular chassis which can flex nicely on trails without serious fatigue unlike my previous G.

Nice and refreshing to see someone interested and well versed in the last, true 4WD apart from the Toyota Land Cruiser and Nissan Patrol. Most consider the G ugly and too utilitarian which it truly is.

 

[moribundman]

I didn't know about the Indian-made version. It's good to learn something new. The G was a rare bird in the US until the comfortable "civilian" version with the well-appointed interior came out. I like the utilitarian bare bones version much better. The shape is classic by now. I'm not exactly sure when the G came out, but I remember seeing them in the late '70s or early '80s in Europe, where they were a common military vehicle. That reminds me, French Peugeot also builds the G, possibly only military models. Here's what looks like an armored version: http://mercedes-centrum.cz/klub/image/200402221946_P150.jpg

 

[Gurkha]

The G dates back from the early 30s when MB made it for farmers, IMHO, Unimog and G are truly classic MB vehicles and totally unique in their ways.

Here is a pic of the Gurkha.

 

[moribundman]

Looks good! A real off-roader. Unimogs are great, too. A locksmith here in San Francisco drives an old Unimog as a business vehicle. I'll have to take a picture of it and show it here.

 

[srivett]

The Canadian Army picked up the G wagons last year and the floors are already cracking in them. They don't seem to be the best vehicle for Afganistan. Any comments?

Steve

 

[Gurkha]

Hi Srivett,

Exactly what kind of trouble are they experiencing in Afghanistan, I am aware from that the Hummer too is not doing too well in the Gulf but wasnt aware that the G-Wagen is going through problems too.

When the Indian made G was tested by German 4x4 mag, they bought along a Toyota Land Cruiser as well as Land Rover and their conclusion was that the G outlasted both these vehicles, as a matter of fact, the Land Rover popped the rear during the tests. I have pics from it and it was truly a torture test. The Indian made G has the rear diffs from MB 407 truck which is rated for 3.75T, thereby making it the strongest rear axle ever to be used in a 4WD vehicle.

 

[Gary Allan]

Although your CV joints are suspect, I'd check your motor/trans mounts. I had a "clunk" that evaded my diagnosis for about 7 years (yeah, that long). I only found it when I was changing the CV joints at over 100k. My wrench (a friend actually) said, "hmm ..your mounts are shot". That cursed me, and my new (reman) CV joints were shot in less than 600 miles (the short side) before I could replace the mounts.

Your "coast" condition is the only thing that leads me to think of this possibility.

 

[moribundman]

Hey Gary, my car's motor mounts and front torque rod are in good condition. The transmission mounts seem to be on the soft side and I will replace them soon. As for the clonking noise, it really is rythmic and corresponds to wheel speed/revolutions. Sinc eit comes form the right fornt, I can really think only of one or both CV joints or the wheel bearing. I HOPE it's not the tranny! I haven't gotten around to squeezing under the car again, but I'll take a thorough look this weekend. Last time I drove the car the noise did not show up at all.

 

[Gary Allan]

I'm not aquainted with your front end. Mine has a has a hub that the axle is splined to. That would probably evidense itself with odd tire wear though.

 

[moribundman]

Gary, if you care to take a look, you can see it here:
http://www.audiworld.com/tech/misc27.shtml