The other day I was on The highway doing 65mph, flat ground, no wind, and consistent speed, not towing, in overdrive and the engine rpm would boune about every 30 seconds from 1750 rpm to 2250 rpm back and forth, but it didn't do it when I turned off the O/D. I was told by a friend that if the ABS light was on It could cause this, is this true, my ABS light is on.The truck is a 1997 F-250 psd E4OD 4X4
Thanks

 

The buzz on these trannies is if you get a 100 000 miles and it's still alive your good for a couple hundred more. My 97 1 ton has the original e4od w/ 215000k on it and still shifting hard and strong. However I ran a 2001 1 ton plowing snow and the tranny gave up in a parking lot-reverse only. It gave no sign of of failure just slipped and dead. Needed a torque and several internal components during rebuild. That tranny had 95000k on it. I should mention that when the tranny died the OD light kept flashing, the tranny shop said the computer was storing a code--something to watch for, eh.

 

The ABS light isn't the cause of the problem, but another symptom. If the VSS (Vehicle Speed Sensor) on the rear axle is dying, or some other problem is causing an erratic reading from the VSS, the PCM may light up the ABS warning & cause the torque converter to unlock/lock at random intervals. I first encountered this after roasting a rear-end (failed repair at a Ford stealership); the rear-end got so hot that the VSS went nuts.

 

That VSS deal sounds like it could be the problem, the tranny seems to shift fine and the OD light doesn't blink, but it does seem as if the converter is locking and unlocking. It has 190,000miles on the tranny(no rebuilds), thanks for the help.

 

better get a trans temp gauge! Will give you a better idea what is going on with the tranny and fluid!