1998 Durango tranny issues
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Joined: Jun 2005
Posts: 14,228
Likes: 19
From: Riverton, UT
when you start these trucks the overdrive is automatically engaged, when you are driving if you push od off or tow haul button that locks out the overdrive unit, causing the rpms to change, so yes it will jump a little when you turn OD off or on, it will go up when you turn OD off and down when you turn it ON
now if you are refering to shifting the auto trans into drive from park then yes the rpms will jump and the settle as you shift into gear although i dont usually notice it so i will check to see how much of a jump it is tomorrow when i go out
now if you are refering to shifting the auto trans into drive from park then yes the rpms will jump and the settle as you shift into gear although i dont usually notice it so i will check to see how much of a jump it is tomorrow when i go out
It's called Torque Management. The main reason for Torque Management is to provide a nice coast into the gears (slip) as people contribute a hard shift to transmission failure. Shift kits help take this back out and stop the trans from slipping during the shifts making the transmission bands last a hell of a lot longer. If you engage the "tow" button while you are driving you will see the RPM's drop as the Torque Management is removed and direct torque converter lockup is acheived. This is why you should use the "tow" feature while towing over 1,500 lbs. The heat generated because the Torque Management is on (slipping) takes out the transmission not to mention the back and forth shift. This will burn Overdrive out really quick!
A great desifer of this is next time you are going up a hill (like 6% grade) when you shift into 3rd as going up in normal drive simply push the "tow" botton and watch the RPM's drop 300 just for doing it as the Torque Management is removed and torque convertor lockup is engaged.
