the transmission shifts through all the gears but at really high rpm's. the cruise does'nt work either. now it started jumping between 45 and 55 mph only at sround 1300 rpm. i've replaced the filter in the transmission and the speed sensor. can anyone help? can it possibly be a vacuume line?

 

what do you mean by "jumping"?

 

like shaking badly, almost like if you were running out of gas.

 

forgot it's a 96 ram 1500 5.9L slt

 

The cruise control servo is vacuum controlled. A weak vaccum could render it non working. Another problem that is common is the brake light switch plunger has done it's time. If the brake light switch goes bad, your cruise will not engage, (assuming it has proper vacuum), and your torque converter will lock and unlock if you are on the gas. This could give you a moderate "shuddering" effect if you were at the right speed and throttle position.

You may very well have something else happening. I can also tell you that a bad/corroded trans temp sensor can play tricks as well. Mostly it will prevent the TC from lockup.


Of course I have a 95'. I am not all that familiar with today's technology in any great depth...lol.






Good luck.

 

is the RPM's jumping around like the speedo is?