[GM_Guy]

someone told me that you should not use the "OD" position for in town driving, that you should use the "D" position instead. is this correct, or is either one acceptable? I have been using the "OD" position for a long time without issue

 

[Dj Friction]

Well.....I have always driven in OD......no matter city or country. I do however never use OD when pulling the trailer.

Overdrive will only shift at speed and Rpm's....I guess the reason is to limit the overdrive shift and lock-up position in city driving????

Just a Thought!!!

 

[GaryL]

When I was driving my 89, I always drove it in D around town. It had 3.08 gears and just seemed to lug too much in OD around town.

 

[GM_Guy]

my burb has factory 3.73 posi, so I figured using OD around town would help mileage
I would never use it for towing

 

[84fiero123]

Around town you may notice at times the trany shifting in and out of over drive quite a bit. That will kill your mileage, in town.

It will also give the trany excessive work. In a town like Boston you would never go into OD even if it was engaged.

Now a small town like mine it jumps back and forth a lot, little traffic except during tourist season.

I have a question for ya.

How come during deer season you can shoot the deer, but during tourist season you can’t shoot the tourists?

 

[GM_Guy]

good question

so, I'll start using "D" instead

 

[tbplus10]

I have a question for ya.

How come during deer season you can shoot the deer, but during tourist season you can’t shoot the tourists?

Because Venison taste much better than tourists. The rotting tourist carcases just go to waste.

 

[TA Dave]

As long as the tranny isn't "hunting" for a gear leave it in OD.

And for the record, I always tow in OD (28ft race trailer around 10K lbs). Again as long as it's not hunting for a gear, and the tranny is in good shape, you'll be fine.

A friend has a 97 GMC 3500 Dually with a 7.4/4L80E and has towed in OD since new. He's got 140K miles on it now and pulls a 44ft 5th wheel race trailer.

This is for 4L80's, the 4L60's could be too weak to tow with in OD.

 

[ChevyFan]

I've never had much experience with any OD tranny shifting or hunting for gears. The manual makes it pretty clear that you should never tow anything when in OD, and I take that a small step further, I turned off OD when hauling anything more than a couple of passangers.

 

[Crawdaddy]

I have yet to come on a time when I needed to pull it out of OD. I've never towed with the Burb yet, but if I did, I'd pull it into drive then, but around Slidell, I run in OD and it never seems to hunt for gears while in traffic.

 

[stockchevy1983]

how do u know which tranny u got? only thingi was told was if i had a heavy duty tranny it would be 2 humps on the pan which is what i have. its a 98 yukon

 

[Chevy1997]

od good for highway

Well, it´s true, od off kill mpg specially at town. The system "OD" consist in "metaforically" order to on board computer to change the shifts (or gears, i don´t know the difference) quickly to arrive a "D" position as soon as possible. Homever the transmission will do an excesive use a long of life and it´s probably to fault or bad fuction. In resume, for my experience and friends with gm trucks recommend me that i must to use at town the truck with od off.
OD was builded with the mission to grow up the mpg in usa trucks.

Well, is my inexperienced opinion. I hope to help somebody.

From the south of Cancer trophy...

Viva Chile Mier....
Chev1997

pd: 84fiero123 you are working in a mine?

 

[95CTburb19]

I notice my 95 burb hunts for gears in overdrive but I have no drive. 3 would be a different story all together correct?