To OD or not to OD

[Wayne M]

First of all let me tell you I typically drive my stock truck with OD locked out around town. My rule of thumb is to try and keep the engine RPMs above 1500. Once I get up to around 50 MPH or I am entering a highway I turn the OD on.



After reading a few recent posts I am beginning to question if that is proper. Specifically I am wondering if it puts too much stress on the transmission. One post said that locking out the OD uses up transmission pressure that needs to be used to keep the bands on track, or something like that. The point was that running with the OD off will actually shorten the life of the stock transmission.



My question is simply, what is the proper use of OD?



Thanks. wm

 

[TxDieselKid]

keep on keeping on...

You are doing everything just fine. That is exactly what you are supposed to do from the way I understood Bill K this weekend in Texas.



I have jsut started doing this now because of my COMP box i bought from them, so i need to save my transmission some how



AJB

 

[Tom W]

I suggest not using OD anytime you are under 60mph. You are at most risk of slipping your TC clutch when it is locked at low RPM. I am speaking from experience. Get the DTT upgrades ASAP, You'll be amazed at the improvement.

Tom

 

[JohnE]

I keep the OD button lit as long as possible so I can stomp the gassers around here. Now I find out it is the PC (Pickup Correct) thing to do for your Ram. Go figure?



-John

 

[TxDieselKid]

That's what I meant...

I meant that you should drive with the light on, like the orignal post said in the first paragraph, last line. Sorry for an confusion.



AJB

 

[Wayne M]

Thanks just wanted to validate what I was doing as correct.



wm

 

[hammong]

Your truck will get slightly better fuel economy in-town with higher RPMs and less lugging/strain on the engine, too. I routinely turn my OD off when going slower than 50-55 MPH, and my EGT and boost pressures are WAY down from travelling the same speed and roads with OD engaged. While I know the Cummins loves to "work" - it's easier on everything in the engine and drivetrain to allow the higher RPMs to do the work!



Greg