I was going down the freeway and noticed I was slowing down. Glanced at the rpm's and it was higher than it should be at the speed I was at. So I let off the skinny pedal and slowly hit the gas as I'm watching the rpm's. Rpm's raise slightly and then drop as the TC engaged and was fine until I had to slow down again. TC had slipped a few more times on the way home. Check engine light is on, pulled code p0740. I haven't drove the truck since this happened but wondering if the damage has been done and needs a rebuild. Could it just be the sensor or is the TC fried? Any input would be greatly appreciated. Also 140,000 miles 5.9 2 wheel, check ball is removed and recent filter and oil change.

 

Might be just a failing TCC solenoid.

 

Tough to say with the limited information. Normally you wont notice TCC, if o/d was missing you would definitely notice that and would cause the truck to "slow down" as you put it.

A little more trouble shooting is in order. Manually shift the truck with o/d off, how many times does it shift (rpm drop) Then press the o/d button, what happens?

 

I was cruising as normal and the all of sudden the rpms jump up and I was slowing down. Not to the extreme of loosing O/D, but lost enough speed for me to look down cause I didn't let off the gas. RPMS were at 2200 at 65 MPH approximately where its usually 1750. Just took the truck for a test drive and about 1/4 throttle shifted to 2nd manually at 2000 rpms, got back up to 2000 rpms shifted to third, at about 35-40 mph TC locked, then turned O/D on the rpms jumped for a split second then it shifted into O/D, a second later and TC locked. Did this 4 or 5 times from stoplight to stoplight shifting manually with the same outcome. I did it 1 time with a little bit more throttle and it was the same outcome beside TC locked at 40-45 mph in 3rd gear. O/D seems to be working perfectly. I usually drive around town with O/D off and when I get to 50-55 I will turn O/D on and the rpms always jump up for a quick second.

I found this video that is similar to the problem I had going down the freeway. Where out of nowhere the rpms jump up and the truck is loosing speed, let off the gas for a second and then apply gas and it goes for a little bit and then rpms jump again.

http://www.youtube.com/watch?v=_MJct...eature=related

 

looks like a neutralizing condition. Next time it does it, hit the gas more. RPMS should shoot way up. If so the transmission is neutralizing.

 

At one point I did increase the throttle while this was happening and the RPMS did raise but not to the point that it felt like neutral. I maybe hit 3 k at about half throttle. Since this problem is intermittent is there a sensor that I can replace or does it need a rebuild? Thanks for your time MonteC.

 

Maybe a speed sensor or the tps.

 

which speed sensor, the vehicle speed sensor or the transmission speed sensor

 

I'll go with TPS on this one also.

 

x2 on the TPS