Tow haul and overdrive

gmc6000 wrote:
No, tow/haul does not lock out overdrive on any GM or Ram truck, at least. Tow/haul only changes your shift points on the transmission.

I guess it depends on what one means by "overdrive" but I recently bought a 6-spd 2012 Silverado 1500 to replace our 2005 4-spd Avalanche for towing and in Drive when I engage Tow/Haul it absolutely does lock out 6th gear. If I disengage Tow/Haul while towing at highway speed and happen across a relatively flat section of road only then will the transmission upshift to 6th, otherwise with Tow/Haul engaged the highest it will go is 5th, which as it turns out is right where it needs to be - 2000 rpm in 5th, downshifting occasionally to 4th as road conditions may require.

You were told wrong.

From what I have been told tow haul will not allow use of 6th with the AISIN trans.

MeAgain what say you???

Bedlam wrote:
Tow/haul changes shift points for upshifts and downshifts. It also tries to keep the torque convertor locked to keep transmission temperatures down. You can still lock out higher gears with the shift selector if the transmission is hunting between gears due to your load, speed and terrain combination.

Yup, this is it.

BB_TX wrote:

gmc6000 wrote:
No, tow/haul does not lock out overdrive on any GM or Ram truck, at least. Tow/haul only changes your shift points on the transmission.

If your truck normally shifts into overdrive at, lets say 55 MPH, in tow/haul mode you may need to hit 60-65 before it shifts into overdrive.

Same for Ford. At least for the last 10 yrs or more.

yup, same on my duramax's. you CAN lock out overdrive, but not by selecting tow haul. have to select OD lockout seperately.

and in tow haul the 6 speed shifts into 6th around 62mph. out of tow haul low to mid 50's.

and on my 2015 tow haul also locks up the torque converter clutch for 2nd through 6th gear.

gmc6000 wrote:
No, tow/haul does not lock out overdrive on any GM or Ram truck, at least. Tow/haul only changes your shift points on the transmission.

If your truck normally shifts into overdrive at, lets say 55 MPH, in tow/haul mode you may need to hit 60-65 before it shifts into overdrive.

Same for Ford. At least for the last 10 yrs or more.

Tow/haul changes shift points for upshifts and downshifts. It also tries to keep the torque convertor locked to keep transmission temperatures down. You can still lock out higher gears with the shift selector if the transmission is hunting between gears due to your load, speed and terrain combination.

No, tow/haul does not lock out overdrive on any GM or Ram truck, at least. Tow/haul only changes your shift points on the transmission.

If your truck normally shifts into overdrive at, lets say 55 MPH, in tow/haul mode you may need to hit 60-65 before it shifts into overdrive.

does a 2000 1500 even have tow/haul?