Hey everybody, I have a 1998 Ram 1500 Sport edition with the 318 motor and the 4 speed (46RE?) automatic transmission. Lately I have noticed when I am driving about 40-50 mph the truck shakes/acts like it's lugging (kinda like engaging and disengaging the clutch very rapidly) horribly!! Almost like a terribly bent wheel. The shake happens when the transmission drops into overdrive... The shake disappears when I start to brake and slow down. So that rules out any bent wheel, And I have only noticed the shake happening in overdrive, I cant recall this happening in other gears. Any Ideas? Is my transmission fried? What can I/Should I do?

 

Sounds like the Throttle Position Sensor (TPS) is bad. When looking at the throttle body from the front of the truck, it's the sensor on the right hand side. What happens is it engages the torque converter lock to save fuel mileage in OD, and your bad throttle position sensor makes it engage and disengage (must think the throttle is jumping around). There's a couple ways to test it with a multimeter, you'll want to search the forums for sure.

 

Any codes? Could be a misfire. They're most noticeable when in OD.

 

Misfire. Get the codes read.

 

Nope, checked the dtc's with my superchip. (Just on stock IRS only been on performance a couple times.) it said there were no DTC's

 

what is your tire size and gear ratio?

My first inclination is like JST, the TPS. But also it can be the speed sensor in the transmission (driver side down low).

 

Any pending codes?

 

265/70/16 and 3.55 gears
I drove it this morning and there was no shaking of any sort to be found. Kind of like it only shakes whenever it feels like it.

 

Weather have any influence on it?