Hey guys,

i got a stupid question...

Is it possible that there exists chevys without OD function/ without an OD button to switch on or off?

I was just wondering cause I know it from an '89 single cab stepside, '94 Suburban an '01 Suburban that you use either the shifter or a button on the shifter at the newer models to switch.
Friends of mine got a '96 and the other one a '95 K1500 ext. cab long bed. Both of the don't have any switch! Neither on the gear display nore they have a button at the shifter! What to do when hauling a heavy load?

 

huh that is odd for sure maybe its just in the gear set and not and optional thing?

 

Thanks for your answer. Same I thought too! Just wanted to know what experts are saying...

 

I have 2, one 89 and one 91, both with 700r4s. There is no overdrive switch or button. When placed in th D position the transmission will automatically shift in and out of overdrive. When towing heavy loads, I will run in (D) which will allow the trans to run in overdrive on the flats or slight uphill pulls. When I encounter steep climbs, I drop (manually) into 3rd and this locks out the overdrive.

 

that is interesting does that effect your gas milleage?

 

Gundog is right. You dont need a button in these cars because the Encircled D is Automatic Overdrive(4th Gear). The Plain D is Drive(Overdrive Lockout), simple 3rd Gear.

When you are towing you should or on hilly terrain you should use D(3rd Gear, Overdrive Lockout) to prevent gear hunting as you climb the hill or lugging when you are towing which is essentially the motor revving up and down trying to maintain speed(this is what happens in Overdrive, since it is gear reduction). In all other circumstances, OD is recommended for increased fuel efficiency. Thats why they put the Circle D above or in front of the Plain D because the maker recommends that gear for normal driving.

There is either Circle D and Plain D or Plain D and 3 on the instrument cluster. I have a Suburban that says Plain D and 3, but I also have a G20 that has Circle D and D.

Only old thing I see with OD buttons were Dodge Rams with an OD solenoid on the rear of the 727 case. This is a nice feature for those people restoring older A-, B-, G-Bodies, and full size Chryslers with the intent on making them daily drivers. Key to remember though, use a shorter driveshaft because the trans tail is like a foot longer.

 

O i didnt think about the encircled D i have seen that on a few blazers i forgot they done it like that too.

 

... they dont even have the "(D)" gear option as known of the other trucks - but has the same trans TH700! - thats why I was wondering about...

 

So it must just be in the gear set and and have no way to lock it out

 

what is the question here? Can you drive without Overdrive in a 700R4? Sure, drive in D(if your cluster says Circle D) or 3(if your cluster says D). A 700R4 by its very design is an 4 speed automatic with Overdrive. This transmission WITHOUT Overdrive is the TH400. Same transmission with an Electronic Valve Body is 4L60-E. Overdrive doesnt kick in until the car is above 40mph in most circumstances.