Overdrive option

Red Bowtie · Dec 6, 2016

Ok folks I have owned alot of 88-97 full size silverado trucks and have always wondered why GM trannys go into OD so quick even if not needed like over 35 mph?
Can I splice the OD wire that is working with my brake pedal stop light switch and install my own manual OD switch? Almost like a tow option on the AT lever but my switch will mount on my dash.
Any body ever dun that, if so will it hurt anything , will it help?
Thanx for your answers.

Mike

RichLo · Dec 6, 2016

I dont know what your talking about, my 5-speed stays in 4th for as long as I want it to. lol

You could just manually shift between D and OD and do what your looking for...

Red Bowtie · Dec 6, 2016

LOL
Fraid I dont have that option. All i have is D & 3 on my column. When i put it into 3 its like high gear and the tach is high. I just want to cut my OD off and on with a switch.

df2x4 · Dec 6, 2016

What specific transmission are we talking here? What year is the truck?

First thing that comes to mind for 96+ trucks is to have someone tune the PCM. They can adjust the shift points and OD electronically to some degree.

Red Bowtie · Dec 7, 2016

Not sure of the tranny but its in a 97 2WD Silverado .

beardeddummy · Dec 7, 2016

What your calling overdrive is lockup and it is your friend. it keeps the heat levels down in your transmission. the D and 3 is 4th and 3rd gear.

deejaaa · Dec 7, 2016

beardeddummy said:
What your calling overdrive is lockup and it is your friend. it keeps the heat levels down in your transmission. the D and 3 is 4th and 3rd gear.

yep, TC lockup. you DO need that. keep it in 3 and OD will not kick in.

Red Bowtie · Dec 9, 2016

only problem with that deejaaa is when i shift into 3 then it won't go into 4th either.
decisions, decisions

df2x4 · Dec 9, 2016

Like I said earlier, considering you have a Vortec truck with a 4L60E I'd look into a PCM tune. They can adjust shift points and OD. Plus you get more power and the truck will be much more fun to drive. I recommend Black Bear Performance, they tuned my red truck. $250 or so and about five minutes of work to swap the computers.

My red truck now engages OD much later than it did from the factory, and it feels a lot better. Doesn't hunt for gears at all.

df2x4 · Dec 9, 2016

Also forgot to mention, once you pay for the tune you get free re-tunes for life. So if you decide to make a change later on like adding bigger tires or different gears, you can just send the PCM back into Black Bear and they'll adjust the tune to correct your speedometer or whatever other changes are necessary.

Overdrive option

Red Bowtie

OBS Enthusiast

RichLo

E I E I O

Red Bowtie

OBS Enthusiast

df2x4

4L60E Destroyer

Red Bowtie

OBS Enthusiast

beardeddummy

I'm Awesome

deejaaa

Became Less Of A Human 5-13-18

Red Bowtie

OBS Enthusiast

df2x4

4L60E Destroyer

df2x4

4L60E Destroyer

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