[Real1shepherd]

The wagon has a wobble now occasionally when I start from a stop, straight line, starting around 10mph and over @20mph....fine after that. Wheel bearings seem fine, lower ball joints firm, all steering related stuff replaced. I do need new struts and I've not replaced the lower control arm bushes....but that's about it. New flex joints last yr....except the 4Matic shaft(one). This all started when I replaced the 4Matic brain with the spare and turned the system on FUNCTION for the season. Mr.Obvious moment, as I don't see the connection. Also recently rebooted and greased the front axle shafts, but no wobble after I did that. There was some vibration @60mph which freaked me out. But each tire was over an ounce off and that seemed to cure the high speed vibration....for now. Always waiting for the other shoe to drop with a high mileage $Matic.

Pretty glamorous....for the second or so it happens, feels like a wheel is falling off.

Kevin

 

[justboo2u]

If you're talking side-2-side wobble, it is almost always a bad tire/bent rim...
New or not...

Have someone drive SLOWLY in front of you or spin the wheel off the ground and look for tread walking sideways...

... almost ALWAYS.

 

[Real1shepherd]

But they were both just balanced in the fancy schmancy computer machine. Surely that scenario would have shown up?? Otherwise, a good suggestion.:thumbsup:

I would think too; if the rim was bent or a bad tire, that would be a fixed constant, not a 'sometimes' issue, right? If you look at the front of the car while this happens, you can see the front yaw right & left....very unsettling.

Kevin

 

[Zeitgeist]

In my experience wobbles are nearly always due to out of round tires or really poorly balanced wheels

 

[sbaert]

4Matic flex joint is a definite possibility and would be in sync with the symptoms disappearing when reaching about 20mph which is about the same speed when 4Matic disengages.

 

[justboo2u]

But they were both just balanced in the fancy schmancy computer machine. Surely that scenario would have shown up?? Otherwise, a good suggestion.:thumbsup:

I would think too; if the rim was bent or a bad tire, that would be a fixed constant, not a 'sometimes' issue, right? If you look at the front of the car while this happens, you can see the front yaw right & left....very unsettling.

Kevin

A 'wiggle' is typically hidden by the speed a dynamic balancer uses... that is where the technician is supposed to say 'oh! this sucker is screwy!'...
And no, a bad tire can have a slipping belt that does NOT remain 'fixed' in place... thus multiple balancings that never resolve the problem.

Just sayin'

 

[Real1shepherd]

OK, well another clue may be that the car was sitting on its tires since late spring....although they never went flat. They are winter tires-Toyo. The 4Matic flex disc I can replace pretty easily and probably should anyway. Also, they poured that TC shaft next to the transmission. I've never seen a shaft so close to vitals.....seems like it would touch something if the flex joint was going out.

So if I spin the tire by hand, I should see something weird with the tire tread tracking(assuming the rim is OK)? When it does the 'wobble', the power steering absorbs it...the steering wheel never pitches violently. Maybe a plan of attack should be to do the flex joint and then present the car again with the complaint to the tire place.

Kevin

 

[Bruce Sloane]

switch tires front to back ..??

 

[Real1shepherd]

switch tires front to back ..??

Yeah, thought about that. But if it is a bad tire, I don't want it just switched to the back....I want it gone & replaced. That's the tire shop's call on the tire part. Meanwhile, I replace the 4Matic flex joint I'm thinking. I know when I go in there, typically they will try to point at other things like steering and suspension. They'll lose that argument, because everything is new or tight.

Kevin

 

[smp22]

Moving front tires to back is easier than replacing the flex joint and much quicker. That will quickly tell you if what you're dealing with is a tire problem or something else. Worry about convincing the tire place once you've got it figured out.

 

[Real1shepherd]

Agreed, but I have to do that in the dirt with limited equipment. That would save me one trip to the tire dealer though, just to prove a point.

Kevin

 

[sbaert]

The more I think about it the more I'm convinced it is most likely the flex joint.

Your symptoms remind me of a Lotus Elan with failing rotoflex axleshaft couplings.

Wobble, wobble until the joint explodes. Yours is only different in that the joint is disengaged before the car picks up speed.

 

[Real1shepherd]

Well, two things; I go back into TEST mode and then the gear train just travels-no torque applied. Or, I go out and rotate the tires...already started on that. If the tire rotation cures it, we know it's not the impending flex joint. Still gonna replace the flex joint though and was gonna do it when I did the front axles....but there was so much drama in that, I just wanted it back on the road.

Kevin

 

[justboo2u]

Move tire to the rear... if it is the tire the body of the car will wiggle at slow speeds (which is where I thought it was...)

 

[Real1shepherd]

Rotated front tires to rear, X pattern. Drove around for about ten minutes and no wobble. Was headed to the tire dealer when the wobble started again. About 85% of the time after taking off from a start @10-25mph. Convinced now it's the 4Matic system, I switch over to TEST and NO wobble.

My darkest fear and Steve's assessment is that it's the 4Matic system. However, I think it's not the flex disc, but rather the front axles. I can't say they weren't doing this before, because the 4Matic system has been in TEST since last April. On one side, the inner boot was ruptured and flinging grease everywhere, but I was careful not to drive it when it was raining or puddles.

The flex disc is easy....so I'll do that, but I'm betting it's an axle. Which means $$$ even for a reman exchange.

Kevin

 

[MichaelBenz300e]

If you have a good spare, I assume most MB's do. Substitute one at a time. that way if you have a wobble still you go onto the next wheel until you find the bad one.
As for the flex disc, I fear this on mine, due to the fact I fill the slight wobble when cold more, and that I just replaced my motor mounts. and the engine is much more soft setting. This I believe could be a issue that allows the wobble be felt more than with a stiff settled mount. Theory that once the wobble....worn....broken disc rotates at slow speed the engine mount is less likely to keep this motion from increasing.

 

[Real1shepherd]

If you have a good spare, I assume most MB's do. Substitute one at a time. that way if you have a wobble still you go onto the next wheel until you find the bad one.
As for the flex disc, I fear this on mine, due to the fact I fill the slight wobble when cold more, and that I just replaced my motor mounts. and the engine is much more soft setting. This I believe could be a issue that allows the wobble be felt more than with a stiff settled mount. Theory that once the wobble....worn....broken disc rotates at slow speed the engine mount is less likely to keep this motion from increasing.

No wobble with 4Matic in TEST.....so it's down to what part of the system is causing this. Did the motor mounts yrs ago and most of the front end stuff, along with the carrier bearing and both flex discs on the driveshaft.

Kevin

 

[Real1shepherd]

Ordered the 4Matic flex disc for $66 + shipping from parts.com. Should be here by the weekend. I'm still betting it's an axle shaft......owning and living with a 4Matic, you have to think think darkly for the worst. I have what seems like more play in the driver's side axle and this was the one that had the ruptured inner boot....slinging grease everywhere.

Kevin

 

[Real1shepherd]

Oh and thanks guys for all the suggestions and inputs!:thumbsup:

I'll put the flex disc in as soon as it arrives and report back. I contacted CVJ axles to see how much their remans are with my cores. They don't respond. I'm gonna guess in the neighborhood of $500+ea.....given the cost of new ones. I'd probably do the one that ruptured first and see if that's the culprit....can't do both going into my slow season.

They're saying a hell of a snowy, brutal winter here.....predicting some snow next week.

Kevin

 

[Real1shepherd]

*Update*

A guy name Steve finally contacted me from CVJ Axles. They are out of my cores and so will rebuild mine for $159.00ea, plus shipping. Warranty for a yr. They don't grind out the hardness on your housing hubs and replace with bigger bearings. Sounds like they do it right. Here's their link...tell me what ya think:
CVJ Axles - Remanufactured Axles & Power Racks

Kevin