LJDC

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]

navyshrink

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.

LJDC

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

shawnvw

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

flycast47

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).