arround 50 mph on the highway when i accelerate i can feel a slight vibration. As the rpms increase the vibration get worse. When i cost it doesnt vibrate. When i put it into neutral and rev, it doesnt vibrate. If i start at mph and floor it, it doesnt vigbrate untill arround 50 mph. It feels like it is coming from my transmittion. I added some transmition slip fix, but it didnt fix the problem. CAN YOU HELP? Thanks

 

oh, and i noticed that sometimes between and 2nd and 3rd gear it over revs b4 it shifts.. its rare though.

!!! hwy the hell is my sig pic so big!? ill have to fix that pronto.

 

Any check engine light? Could be you have a failing coil. Often mistaken for transmission problem. When was the last time the truck had a FULL tune up? If its been anywhere near 100k thats where you need to start.

 

no engine light, its a 1998, and what do you mean by "FULL" i just wanna know all of what i have to do.

 

motor? what brand spark plugs? and wires if 4.6 or 4.2? when was the fuel filter last changed? maf ever been cleaned?

 

When I last tuned up my truck I replaced the coils and the plugs cleaned the throttle body the maf replaced the IAC the front o2's the fuel filter and air filter of course. I also serviced my transmission fluid filter... some of that like the fuel filter and MAf I do every year and actually I clean the MAF every 4 months because I have the K&N oil filter. If you havent done any of that for along time it needs it no mater what.

 

4.6l v8. auto zone wires which i have had problems with int he past.... but they have lifetime so i keep using them :/ i changed the fuiel filter like 1.3 years ago. i have never cleaned the maf. the plugs are from autozone, but they were an upper quality type. and i changed em out same time i did with the wires.

 

I dont know if i have coils.... i dont think my year does... i shouldnt need to replace the plugs they are like 2 years old. i need to clean the throttle body for sure. i didnt change the transmission fuild filter. i should prolly do that at a shop huh?

 

Modulars only like motorcrat wires and are very picky about the plugs. I would only use motorcraft myself and highly recommend you get rid of those wires..

 

you have coil packs. They either work or the dont I suspect your problem is the wires. Transmission maintenance is commonly neglected. whole lot cheaper to drain and fill the tranny and drop the 14 bolts holding the pan on and replace the filter theen it is to spend a couple grand on a new tranny. I do the tranny every 2 years.

 

yeah i will for sure get an appointment for maintenance. i will change out the wires myself. and c what happens.

 

where is the most convinent place to get motorcraft wires...

 

I would try rock auto if you want to get them at a discount online. The only other place you probably could get them is from your local ford dealer.

 

okay will do