od lockout

windmillcowboy · 05-09-2007, 10:03 AM

the other day i had a 32' stock trailer loaded with 21 700# calves and a 1800# bull. I could build speed until it shifted into over drive. is there ne way I can lock out the over drive? It makes me mad cuz it will do good, until it shifts to od and it always varys sumtimes it will shift at 50 and sumtimes at 60. I think i could really move down the road if i can lock it out until about 65 then hit overdrive when the rpms are up there.

2002 chevy 2500HD with dura/allison

**TYREBOYZ_DEMAXIN** · 05-09-2007, 10:29 AM

on the very end of your gear shifter you'll see the T/Haul button hit and hold that button and it will turn the OD off..it does this for my 05 chevy with the ally tranny

windmillcowboy · 05-09-2007, 10:38 AM

this one doesnt do that i have tried it, my buddies 03 does so I guess they must have changed it after mine was built.

duramax69 · 05-10-2007, 08:17 AM

yeah i have an 02 and i have experienced this same exact problem. my buddy has on 05 and he can lock his out too. anybody out there have any suggestions.

duramax69 · 05-10-2007, 08:21 AM

oooooooooooooooo, i just had a brilliant idea. mine is chipped and i can change the shift points. i have not experimented w/ changing the shift points but possibly you could change and make higher rpms before shifting into o/d. is yer dmax chipped cowboy???

windmillcowboy · 05-12-2007, 01:31 PM

no. If u get somthin figured out let me know.

**ob_1jr** · 05-12-2007, 03:29 PM

Go to kennedydiesel.com. He has instructions on how to install a switch for the 2001-2002 trucks. When you get to his site, go to tech tips, duramax tips, and scroll down. You will see a link for the Overdrive Lock out Switch installation. You can contact kennedy or eric (gmdieseltech.com)for the parts or just get them from the dealership or gmpartsdirect.com. Hope this helps.