Hey all I tried searching for this issue with no luck on my end.

So if you are driving about 60MPH and above with cruise set or not but keep a steady gas pedal the RPMs will jump up about 800-1000 and drop back down. It will do this over and over again even if you turn off the O/D.

It's doesn't seem like it is slipping, but almost like a torque converter locking and unlocking.

Specs:
1999 Ram 1500
5.9 360
Automatic
3" procomp lift
285/75/16 mickies
3.55 gears
127,000

Any help is greatly appreciated!

 

is that the only speed where this issue arises? are there any other shifting issues? almost sounds like a govenor issue within the trans itself or a tps issue. First thing i would do is get a scan test done to see if there are any codes that have popped up. Trans code may not trigger the engine light..

 

It shifts just fine, does this at about 55MPH and faster. I haven't pulled any codes yet but may need to try.

 

I thought I've heard of others out having similar issues like this but couldn't find an answer. Maybe I should post a video of what does.

 

Was thinking TPS until I got to the 1000 rpm jump. Sounds like it's downshifting almost. Does it matter if your on flat road or slight inclines? I would see if you can pull any stored codes, if not, then I would go to my tran man and have him drive it with his expensive scanner. Just what I would do.

 

Flat ground, up hill, or down hill is all the same. If I stand on it it won't do it. I'm just going to record it next time I'm driving it so it gives a clear picture of what it does. Last owner said it has done it since 20,000 miles. Also towed his Jeepster trail rig to Moab twice from eastern Colorado with no issues other then this one.

 

Seems like it is dropping out of O/D.... TCC is only a 200 rpm change. Check the wiring at the trans, and PCM. See if something isn't loose, or dirty. If that all looks good, time to go into the trans, and replace some solenoids.

 

Maybe I should look closer at the RPM gauge. This weekend I'll have more time to focus on this.

 

Got a video of it.

 

Anyone have an idea of what this would be?