yeah I just started noticing that after I get on the gas in my truck to hop on the highway or freeway speeds Ill slow down and maintain a somewhat constant speed but I feel this almost shudder feeling or vibration coming from the drivetrain Im assuming. any ideas or help guys?

 

check your u- joints.

 

i have a 93 f150 that did the same thing at first i thought it was the wires or plugs but found out if you do any towing the oil gets hot and damages the clutches so now i have a rebuilt tranny and a large oil cooler

 

last tranny change?

 

well I dont know I got the truck as a gift from a freind of the family who doesnt know much at all its a 93 lightning and he used to do a bit of towing with the truck the rear was "serviced" by his freind not too long ago for having bad spider gears and the day after he got it he lost the keys.. it then sat for a year until I got it and put in a new key cylinder but noticed this really bad shudder/vibration in my seat. I dont think he ever had the transmission serviced in the 4 years he owned it. he said he had the tranny fluid changed because walmart told him it was burnt lol but I thought Id ask you guys for help so I'll look at the u joints then first? any particular one that should fail before the other? thanks
:santa:

 

If you have an LS rear end, that would be suspect as well . In later models 97-03's have this problem when they reach 45mph . It's due to a break down in fluid viscosity or lack of friction modifier properties in the rear end. Changing the fluid could resolve your problem.

Theres also have been spline grease problems (Ford has a TSB on it) - Lack of grease , but thats more of a cluncking problem at low speeds.

Some more possibilities for yuh

Good Luck