okay this is the 'problem'[/align]whole trucks 'shakes' between 60-66mph[/align]have already done the following[/align][/align]Nov 06 the trainy had to be redone...i still do not think its right though[/align]all thru 2007 the following has been done to 'try' and fix this issue[/align][/align]complete tune-up .... as we know is far from cheap for the truck[/align]the spider has been done twice.....they redid it under warrenty thinking that it was defective[/align]the belt has been replaced [/align]the EGR valve...thevalve by the 4th cylinder[/align]they redid all the wires &plugs again also.....[/align]the distributer cap....[/align]compression test[/align]keeps coming up the 4th cylinder...........[/align]um a sensor was also done.....[/align][/align]still shakes at the same mph...HELP!!!!![/align]

 

Your problem is most likely that your tires need to be balanced. Occasionally you lose a weight and you get a shimmy at a specific speed usually between 60-70 mph.

 

thats the other thing I did have done 'twice'...

 

driveshaft imbalance?...sometimes a weight will come off and cause a vibration

 

Similar problem with our '99 Suburban was due to bad universal joints. The OE joints cannot be lubricated and will lose their lubricant by 90,000 to 120,000 miles. Replacement u-joints have lubrication fittings on them and should last much longer (if you grease them).