Arbitration Works

[HC]

I can't believe I'm saying this:



If you had a 2WD and weren't unhappy, you should stay with 2WD. Less to break, higher mpg, my 2WD friends aren't complaining about "wander".



The other side of the coin is that I know I would be unhappy with 2WD. Too many of my friends have 4WD, and with the back-roads I drive under often muddy and sometimes snowy conditions I would be begging for a ride, or a tug, way too often. I've even had to lock in 4WD just to back out of a gravel driveway.



You gotta figure which side of the coin looks better to you!

 

[Shelby Griggs]

Other Causes?

Has anybody looked into other causes for the shudder? I have a 1989 Grand AM with a bunch of miles. Awhile back I got new tires and new brakes around the same time. The rear drums were replaced on the brake job. Shortly thereafter I noticed a vibration or shudder. The passenger seat would vibrate when empty, and I felt some side to side motion. Tried a lot of different things, including new tires and rims. Everybody had me convinced that it could not be the new brake drums, because it would have to be one heck of an out of balance condition with those small drums to cause a problem. I finally replaced the drums, more out of desperation than anything and problem was gone.



I wonder if the shudder could be out of balance drums? Is this problem occurring on the newer trucks with discs at all 4 corners?



Just another thought.



Shelby

 

[MChilds]

Other Causes?

Shelby, that’s a really good thought. I mentioned to the Dodge dealer that was trying to fix my truck that the problem became worse when the truck warmed up and thought it may be a warped rear rotor or something getting hot and growing in the rear brakes. They claimed they checked them with a dial indicator and also the proportioning valve to see if it was keeping too much residual pressure in the calipers.



One day, I drove the truck until the shudder got really bad, came home and jacked it up and quickly removed the rear wheels. Both rotors turned easily so I don’t think it was that. However, nobody ever checked for balance and now that I think about it, those rotors are a one-piece rotor/hub and probably pretty heavy. I sure find it interesting that your problem caused a side-to-side shudder; I thought a wheel or drum problem would mostly be felt up and down like an out-of-balance tire.



Does your 89 Pontiac have a limited slip rear end? (My truck does) Maybe if one drum (or rotor) was really bad, it might do strange things to the limited slip clutches and cause a side-to-side shudder. Now that I think about it, my 98 4X4 had rear drums and it was slick as snot. (After I put Michelins on that is)



I know that no matter what DC did to the drive shaft, it never really changed my original complaint. You might just be on to something…

 

[Shelby Griggs]

The Pontiac is front wheel drive, rear drums. My problem was that the replacment drum(s) were out of balance. Drove me nuts for a few thousand miles, until I insisted that they replace the drums. The problem went away, so I can only assume that it was an out of balance drum. I would think an out of balance disc would have the same problem. May be worth a shot?



Shelby

 

[MChilds]

Shud-a-rama

Shelby; it’s too late now that I’ve agreed to the arbitrators decision to have DC replace my truck. You can bet if the next one shudders, I’ll be after the rotors myself. Thanks.

 

[SteveH]

Hey MChilds,

Do a search on "death wobble" and you will see that some of us posted many months ago about a problem called a death wobble because it was so violent. I have been working with DC for several years trying to solve my 1 ton's problem. We can now reproduce the wobble nearly anytime we wish. 8 DC technicians from back east and one from Denver have been feeding ideas to our local dealership trying to fix this problem. We have shimmed the driveline to be as straight as possible, shimmed the carrier bearing, balanced drivelines, new drivelines, new tires, new springs, shocks, stab shocks, steering column, new entire driveline assembly including the carrier bearing, new positrac rear end, new entire axle and springs for the rear end, etc, etc. We've driven it without any rear driveline at all. High speed balanced the tires and balanced both rear tires on each side while they were still on the truck. We've checked the castor, cambor and would have checked the camphor if it had one.



ALL of the ideas posted by TDR members as to causes have been eliminated and did not solve anything. (The ideas were appreciated but just didn't solve any of the problem. ) DC sent a vib machine that has been hooked up to my truck several times and records the harmonics and hertz involved with the "vibration". The machine pointed to a single hertz range harmonically attuned to the output shaft of the transfer case. Translated to mean that the output shaft was probably not perfectly straight. After a new transfer case was installed, the problem still exists.



Our local 5 Star has bent over backward trying to fix the problem including taking the rig to an independent who helps build driveline systems for professional racers. The DC people on the other hand have been arse oles. One even made a comment that I just shouldn't drive so fast. Right now I'm waiting for their buy-back offer. They said I would hear from them this coming week.



I apologize for the longer than normal post but this is a serious problem that creates a safety concern and DC doesn't seem to be handling it very well. As far as a 2WD vrs. the 4WD. If you live up here where the snow falls quite often, there is no question - 4wd.

STeve H.

 

[monkfarm]

my $.02

My 3500 6X4 has never shuddered. I have pulled up to 22000.

 

[MChilds]

Death Wobble

Steve; I did the search but never did find the info on the Death Wobble. But then again, I’ve never been able to make the search thingy work anyway. It sounds like you’ve really been through it with the same delay, deny and blame it on the customer responses that are programmed into DC representatives. My favorite used to be “It’s the first time we’re ever heard of this problem” but now (and probably due to dealing with DC) it’s “ It’s within specs” or “It’s a characteristic of the vehicle. ”



If there is one thing I have learned from this yearlong experience is that if you have a problem, don’t try and fix it yourself or drive any farther than you have to; even if you win at arbitration you’ll pay a mileage charge. In my case, I first took the truck back at 245 miles but by the time I prevailed at arbitration, I had 22,000 miles and $1,200 in attempted repairs out of my own pocket. Not to mention all the wasted time, which from the sounds of it was a lot less than what you’ve invested. The arbitrator only made me pay for half the miles but had I insisted that DC fix it in the first place and not give them the benefit of the doubt, I could’ve gotten a new truck for zero.



Here’s a thought on your truck. I measured my frame square by dropping a plumb line from a number of identical places from the frame to the floor and then marked the floor. Turns out, my truck was about 5/8-3/4’ out of square, in other words, the frame was ‘racked’. DC claims that that couldn’t cause a shudder and of course it was within specs. I would be interested to know if your frame is square…

 

[MChilds]

Big Trucks for all

Monkfarm, does that long-nose Peterbuilt shudder…or just rock? Boy do I miss driving a big truck.



Mike

 

[monkfarm]

petebilt

No shudder or rock on the Pete, especially since i put Michelins on the steers, it's rock steady. And it's heavy enough, when other truckers are complaining about the wind ( like interstate 80 in Wyoming), as long as i keep my foot in it, the wind doesn't bother me.

I had a set of Bridgestones on the steers and they started going out of round. I was too cheap to replace um for about 20,000 miles, and what a shudder would happen about 73 miles an hour, yeow!!. I'm going out again monday; 10 days. . .

It does get in your blood , doen't it

 

[MChilds]

Big Truck II

Yep, it does get in your blood. I’m not sure why with all the problems with trucking now, but it does and I miss it. Couldn’t wait to get home and then couldn’t wait to go again.



Never was fortunate enough to have a Pete and never quite made it to 500HP either (got to 425 though). Couple of Freight Shakers and A Volvo VNL (nice truck) with Volvo’s motor was about it. BTW, the Volvo motor was absolutely perfect and their exhaust brake coupled with their own engine brake was great. We went out at about 55,000 usually and with a garden variety 10-speed over got between 6. 5 and 8MPH at legal speed limits +5.



Have fun and remember the sure cure for a shudder at 73 is to ease it on up to 75.