Engine Braking

[Dipdngold]

96 chevy 1500
4.3 engine

When going down steep grades, why doesn't my transmission stay in the lower gear that I choose to help me slow down? Is there anything that I can do to make it stay locked in the gear for the additional braking?

[tlperry68]

What kind of transmission do you have?
Some transmissions (mine included) won't let me start from a dead stop in say 3rd gear.
Does your truck have automatic descent control or the manual selection?

[Dipdngold]

I don't know what kind of tranmission I have. My selector has d 3 2 1 so I guess I have the manual selection. There are no other buttons or signs for additional transmission options.
I'll try and start out in 3rd gear and let you know what happens.

[tbplus10]

It doesnt stay in lower gears when coasting down hill because you dont have a locking torque convertor and your valve body is designed to automatically upshift no matter what position the gear selector is in. The torque convertor is running upto the shift point in each gear and then the valve body is shifting to the next higher gear.
The reasons are multiple:
To stop the transmission from overheating itself and toasting the internals.
To stop from over reving the engine and toasting it.
And to stop from running the engine at high RPMs and heating it up to where the radiator boils over.

You can buy and install a manual valve body kit and a lock up torque convertor for your transmission so you'll have this ability but your truck was intentionally designed this way to stop you from destroying the drivetrain. There were some later 4L60e's and 4L80e's that came factory with an electronic lock up torque convertor I just dont know if this was an option with the 4.3 engine as I've never seen it on models equiped with that engine.

And unless someone replaced it you should have a 4L60e transmission.

[Dipdngold]

Thank you for that information.