2001 5.9 auto 4x4 w/166,000 miles . 1st time this has happened - slight downhill grade after backing off the gas pedal for traffic reapplied gas and RPM jumped with no response in speed . Had to limp home at no more than 30 - 40 mph. RPMs would jump and transmission would leave me with no power at around 30 to 40 mph, slowing down would allow xmission to re engage. Also sitting at a stop sometimes xmission would not engage or will take a while to engage in gear. What should I be looking for as a cause of problems ?

 

Check your fluid level first. Make sure the truck is running, level, and in neutral. If the fluid level is good, check the color. If it's starting to turn brown, you want to change the fluid and filter.

 

my truck the 1st gear was slipping really bad, so i went down to a local tranny shop and they looked at it was like good timing, i almost blew my tranny if i kept driving it like it was. my problem was the cilanoids and something else . it was about 400$,

you might want to go down to your local tranny shop and tell them and have someone test drive, and look at it, you dont want to buy a 1500$ tranny.