I read through the tranny posts and did not find an answer to this so here goes. Does it hurt to disengage overdrive on an 06 F-150 now and then. I daily drive a long mountain and if you leave the truck in OD you are continuously riding the brakes to keep your speed down but if I disengage OD the engine seems to keep my speed in check eliminating the need to ride the brakes all the way down the mountain. Is this a bad idea? If so I realize it would be cheaper to replace brakes and rotors over having the transmission rebuilt or replaced. Thanks

 

If you read your owner's manual it tells you to turn off overdrive to help control your speed going downhill. That's why they put the button there.

 

It does no harm to disengage the OD, in fact it is recommended in certain cases. If going up a hill and the trannie is locking and unlocking the torque convertor or going back and forth between 3 and 4th, lock it out. If your top speed in an area is only about 40-45, you can easily lock it out so it doesn't hunt for gears. Same is true for towing, if it is hunting, lock it out.
As far as locking it out going downhill, it is no different than downshifting to 2nd for the same reason. Just using the engine for braking.

 

I drive everywhere with mine locked out even the local highway(speed limit 70mph 3.55 gears). It helps my gas mileage for some strange reason. I need to change my rear gears to 4.10 or 4.56. It makes towing easier too. You can get just a correction unit if you don't get a tuner.

 

Thanks guys. I actually did read that you could use it to control downhill speed but one thing I have learned in my 50+ years is to never believe everything you read in a book ; ) I appreciate the replies.

 

They wouldn't put the button in such an easy place to use if they didn't want you to use it.