Duramax/Allison downshift? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1976gmc20 · 04-19-2021, 02:17 PM

This morning my daughter called from Nebraska on her way west with a gooseneck and horses. She said her truck is slow to downshift on moderate hills on the interstate, like it's staying in overdrive.

It only has D 3 2 1 so Drive apparently includes overdrive, and no way to manually get it down to direct. She said she has to totally mash the pedal to get it to shift down a gear.

So my question is there "kickdown cable" on these or is it all electric?

Also, the tow/haul button doesn't seem to be having any effect, even though the dash indicator comes on. I told her to manually shift it down going over Monarch Pass, when she starts getting down under 50 mph.

(2002 K2500HD)

04-19-2021, 02:17 PM	#1
1976gmc20 Registered User Join Date: May 2015 Location: Montana Posts: 3,696	Duramax/Allison downshift? This morning my daughter called from Nebraska on her way west with a gooseneck and horses. She said her truck is slow to downshift on moderate hills on the interstate, like it's staying in overdrive. It only has D 3 2 1 so Drive apparently includes overdrive, and no way to manually get it down to direct. She said she has to totally mash the pedal to get it to shift down a gear. So my question is there "kickdown cable" on these or is it all electric? Also, the tow/haul button doesn't seem to be having any effect, even though the dash indicator comes on. I told her to manually shift it down going over Monarch Pass, when she starts getting down under 50 mph. (2002 K2500HD) __________________ Current/past Chevy/GMC trucks: 1958 Chevy C-60; 1965 GMC C-50; 1965 Chevy C-10; 1971 Chevy K-10; 1973 Chevy K-20; 1976 GMC C-20; 1977 Chevy C-10 Suburban; 1980 Chevy K-10; 1989 Chevy K1500; 1991 GMC V1500 Suburban; 2016 Chevy K2500 HD Other vehicles: 1988 Jeep XJ; 2011 Toyota 4Runner



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