I have a 96 F-150 5.0, auto trans (with factory cooler) 4 wheel drive. It has about 95K miles.

I'm getting a vibration that comes on at about 45 mph, and goes away at 50 mph. I'm pretty certain it's in the transmission, because if I take it out of OD when it's vibrating, it goes away instantly. If I take it out of OD before it vibrates, it never happens.

Last tranny service was at about 50K, so I'm due. Is this a symptom of a bigger problem? I'm not certain which trans I have but can find out if that would help any of you experts.

 

For the record, according to the ID method down the tranny thread, it would appear that I have a 4r70w trans in it. Also, the fluid is full, but not overfilled. Also, the fluid doesn't look or smell bad.

 

Sounds like torque converter shudder to me. Check your spark plug wires first.
Alan

 

I agree with dirty, sounds like torwue converter shutter, had that problem on a '96 Cougar XR7 with a 4R70W

 

Thanks guys, I will throw a new set of plugs and wires at it when I get back from vacation. (no, we're not taking the truck.)

What you're saying is starting to make a LOT of sense, since I just noticed the last couple of days that I'm getting the shudder at about 1500 rpm in the regular gears w/o OD.

I'll post the results

Thanks again

 

Dirtydog and Inlinesix- you guys are great!!!!!!! Put new plugs and wires on it, and my shudder is completely gone. As expected, I got some extra power (And probably mileage) in the deal.

I REALLY appreciate your input, guys. I was starting to get scared about the transmission.

Thank you doesn't begin to cover it.

Brian

 

Glad you got it fixed.
Alan