VIBRATION Somewhere Underneath

[IBEX95]

My 1999 G320 starts to vibrate (somewhere underneath) at about 50 mph (between 50 and 60 mph).
But it seems to go away after 60 mph. Also at lower speed (below 50), the car drive really fine.
My tires are new Michelin, they are professionally balanced/rotated. Recent computerized wheels alignment.
New Tie-rod ends and new Drag-Link installed.
I did search the internet for similar problems, and see that many MB owners heve the same issue,
but I was not able to find anything particularly about my car.
So I will greatly appreciate if you could point me out where/how to look for and determine the source of the problem(s).

 

[Vagabroads]

I know it's a different type of car, but I had a similar issue after the front driveshaft u-joints were replaced on my landcruiser. It turned out that driveshaft needed to be balanced. I had it done a a driveshaft shop but I think a dealer can do it too. Hope that helps.


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[Metric]

Tcase mounts, intermediate driveshaft, and wheel bearings are places to check at this point. Maybe post over on pointedthree or clubgwagen for more technical support.

 

[Retired Tanker]

You can tell a lot from the frequency and location of the vibration. Get an experienced mechanic to ride with you, even if it's just a buddy. The location is hard to pinpoint when you're stuck in the driver's seat. A passenger can move around in the cabin to locate the source.

 

[thairish]

Tires changed recently? Get them road force balanced at a different, more experienced shop. This is a common root cause and best place to start.

 

[zimm]

i have a g320, its the center shaft. unless its been going on for quite some time unaddressed i doubt you will need new tcase mounts. i'd do the shaft first and see. put your hand on the locking shift, and feel for motion coming on at the same time as the vibration.

as far as servicing the existing shaft, i wouldnt bother. lack of maintenance has has toasted it. i believe you can use 100 dollar vw/audi cv's on the ends with some machining to put the en caps back on, but that seemed like a pain, and any wear on the shaft itself would rear its head at some point, in addition to the possibility of it being out of balance. the factory shafts ought to come balanced.

replacing with a 461 style ujoint shaft as opposed to CV's may be an option. i would think its easier to grease and keep an eye on. i never followed up to much on it though.

i get most of my service parts from Eurotruck. just call and tell shawn whats going on and he'll steer you right. dont bother with a stupid shop unless they work on these frequently or you'll be tossing 1500 dollar darts at a dart board.

http://www.eurotruck-importers.com/index.php?main_page=product_info&cPath=2_88&products_id=1485

 

[Firesong]

Driveshaft. U joints and balancing.

 

[IBEX95]

Thank you all very much. Today I was at the Mercedes repair-shop. Mechanic took my G to the road test. After returning back to the shop he said that the vibration fills and sounds like it is from the Torque Converter. Then he decided to do another test - he connected computer to the computer-port under the hood (my G is European. It has two computer ports, one is under the steering wheel and the other in the engine compartment) in order to disengage the torque converter and to do the drive-test again. Vibration continued even with the disengaged torque converter - so for me it's a good news - one $$$$$ probable cause is eliminated out of the list. My next step is as recommended here - I will take my G to the driveshaft shop (hopefully next weekend, or the one after). I will ask to check small prop.shaft first, then the longest one, and so on. Hopefully one of the shaft is out of balance, so it is going to be a quick-fix... I eve afraid to think about what is next, if all-three driveshafts are good... I will post results as soon as I have any news.

 

[zimm]

the small one isnt easy to check, its a pain to take out. unless youve been wheeling, theres no reason to think the rear shaft is out of balance, and, its easy to physically check. considering the labor, i would have a center shaft handy and return it if unused.

the reason its the center shaft, is because of the service labor. nobody wants to pay MB rates. the shaft ends are CV's, NOT ujoints, and if its a '99 you can bet the grease in them is like semi dry clay. if you take it out, and see that, just toss it. DO NOT waste time servicing it at this point. these shafts need serviced every 90,000 miles or every few years (check the grease). 120,000 dollar primadonna vehicles are like primadonna women. when they are old and worn, they dont know it and they still think they are top notch and require 120,000 treatment. i think what happens, is the 2nd and 3rd husbands of these broads, think they are getting the hot chick they saw on cribs for a discount, and balk at the plastic surgery costs. it aint cheap being a poser, either.

the worn drag links and knuckle bearings cause death wobble in these, not vibrations.

you havent said how many miles are on the rig, or when the logbook says the center shaft was serviced last.

 

[Retired Tanker]

I'm betting it's a drive shaft, either a worn CV joint that sets up a harmonic at 50 and then dampens out at 60mph. No mention of "feeling" the vibration (in the steering wheel), nor of "hearing" the vibration (which would indicate a worn diff, flat spots on the tires, wheel bearing). Or, could it be possible that a balancing weight has been scraped off of the shaft?

Any mechanic worth his salt (not sure about someone who would think that a torque converter was the first place to look) would know how to feel for backlash across the CV joints.

 

[IBEX95]

I will follow your advice ZIMM, and will purchase a new center shaft just in case, while working on the current one. If my current central shaft is in good condition I will return the new one. I have a little more then 100,000 miles on the rig. There are many MB mechanics out there, but it is very hard to find a good one who specialize in G-Class and actually know what he is doing. I live in NYC and so far no luck...

 

[Metric]

120,000 dollar primadonna vehicles are like primadonna women. when they are old and worn, they dont know it and they still think they are top notch and require 120,000 treatment. i think what happens, is the 2nd and 3rd husbands of these broads, think they are getting the hot chick they saw on cribs for a discount, and balk at the plastic surgery costs. it aint cheap being a poser, either.

Best post I've read in a while.

If you are in NYC take it to Wolfgang's across the river in NJ. They have a great reputation for Gwagens. Do NOT take it back to the guy who thought it was the torque converter.

 

[IBEX95]

Best post I've read in a while.

If you are in NYC take it to Wolfgang's across the river in NJ. They have a great reputation for Gwagens. Do NOT take it back to the guy who thought it was the torque converter.

Thank you METRIC! I never heard of Wolfgang. I will greatly appreciate if you could give me his address and/or phone #.

 

[Metric]

The shop is in Tenafly? Don't have a number but check this link from P3
http://ww.pointedthree.com/disc/forums/showthread.php?tid=22500&posts=4

 

[NYCRover]

Yes, take it to wolfgangs in Tenafly. Rich will sort it out. Wolfgangs isn't cheap, but you get what you pay for.

265 County Rd, Tenafly, NJ 07670
(201) 568-7003