I need some help and advice, please. I have an '04 2500HD 4x4 LLY/A SB LT with 11,200 miles. In fact I just sent my fourth payment last Friday.

For the past few hundred miles at low speeds (below 15mph) while coasting (foot OFF both pedals) the front end starts shaking violently until I tap the gas or brake. This occurs often when I'm searching for a parking spot at low speeds, again with my foot OFF the brake and gas, just idling along at low speeds. This occurs maybe 75% of the time.

My STEALER calls just a few minutes ago and tried to convince me that it is because my front tires are 'cupped'. While talking with him he slips up and says in the heat of the argument "well you can come ride with our tech and try to reproduce it", which leads me to believe they can't even reproduce my reported problem..... If it IS the tires, then why does this violent shake not occur EVERYTIME I am within that speed range? This problem happens maybe 3/4 of the time, but NOT all the time. If it was the tires, a physical problem with the rubber, wouldn't it cause this problem ALL the time? I know it has to be the front diff, or maybe the tranny trying to lock up? Even the service guy said if I rotate the front tires to the back it would cause a constant roaring. Do cupped tires only cause problems 75% of the time when in front and 100% of the time when in the rear!?

What should I do guys? I've had nothing but problems from this stealer's service department since day one. I'm a heart beat away from going down their and putting the guy through a window. Please give me any opinions on how I can handle this in a civilized manner. Thanks.

colletti, I don't know what is causing your problem but at that speed it is not the tires. Your dealer is grasping for straws. Balance, bad shocks, lower ball joints will cause the cupping. I would take it to another dealer. Later! Frank

Actually alignment can cause cupping too. I have seen cars "shake" front ends as certian speeds with castor/camber and toein problems but not at 15 mph, usually faster. You have a serious alignment issue here that needs to be fixed. ALso, if you have oversized tires on it it will agravate it further. Dealer may not want to fix alignment issue if oversized tires are installed so you will need to good the a non dealer shop if you have them.

Cupped tires will cause the front end to do that, but not only 75% of the time, it will do it all the time and usaully at faster speeds also. Do your front tires show signs of cupping? Have you rotated your tires? Your dealer should fix this for you.

IF they are cupping that bad to begin with there are alignment issues still. Get alignement checked on a good alignment rack.