# Tow/Haul Mode...



## Up North (May 4, 2004)

Yet another Tow/Haul Mode question, I did a quick search but didn't see what I was looking for so here goes...

I have a 2000 1/2 ton ext. cab Silverado with the Blizzard 760LT. Is plowing in Tow/Haul mode going to effect the engine temp? Example, if I'm plowing in "D" without using my Tow/Haul mode could that contribute to my engine temp climbing? 

Reason for asking is I've been having trouble with engine temp climbing during transport. Normally I plow in "D" (drive), with my 4x4 set in "Auto" and tow/haul mode off. After plowing for an extended time the engine temp would climb when in transport (only while in transport, no other time) from one job to another which is usually a few miles or so. Then...I decided to bolt on the Airfoil from Blizzard, seemed to work pretty good but just at the end of my route on my way back home the engine temp started to rise again but this time I adjusted the plow height to allow the Airfoil to direct more air into the frontend, did the trick. Next day another snow day, did the same route, same amount of time plowing, same snow depth, about the same air temp outside. But this time I plowed and drove with my tow/haul mode ON all day and the engine temp never climbed. Could this actually help keep my engine temp from rising? Or coincedence?

Keep in mind I'm not Mr. Goodwrench so if this is an easy question for some of you (TLS, SnoFarmer, Frozen001, Bad Luck, etc. ), please bare with me.

Buck


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## ratlover (May 5, 2003)

in the non allison trucks it may help a little. It will raise shiftpoints ect and do some other things depending ont the trans. 

In an allison it helps a ton more since it keeps the converter locked earlier.

Your probably not nuts


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## G-LSCPE (Jan 27, 2006)

From what I have experienced obviously the plow is blocking the air flow to the grill, causing it to overheat. I am currently experiencing this on my 05 2500HD, and from what I gather there is a clutch fan upgrade for the gm's that is suppose to help the temp control. I am taking mine to the dealer next week. Also if you were to add an electric fan to help cool off, this will help. As far as the tow/haul I don't think it will have much affect on the temp, since it is there to cofntrol shift points.


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## SnoFarmer (Oct 15, 2004)

"this time I plowed and drove with my tow/haul mode ON all day and the engine temp never climbed. Could this actually help keep my engine temp from rising? Or coincedence" Buck--or coincedence...Hummmm..
Take it easy on you, LOL, ole timer:waving: 
I think you answered your own Q, with your test.

Can I make an suggestion? Next time you go plowing use 1st instead of "D".
The more your tranny shifts the more slippage there is, as it shifts gears, generating more heat.
I bet your tranny cooler is in your radiator? Your tranny way be the source of all of your heat buildup?
Just an idea..


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## Bad Luck (Sep 30, 2004)

Buck - I had to experiment a little with this myself when I first put the blade on. I do not use tow haul AT ALL while transporting or plowing. When transporting it was making the truck hold the gear longer, and with less air getting to the rad and the rpm's holding the truck was heating up faster and went over 210 a number of times. I now use just regular D to keep the rpm's down and let the blade hang just low enough so it doesn't hit the ground and angled slightly left when transporting. 

When plowing, I use 4 hi, (with the exception of this past weekend when I used 4 lo quite a bit) and either 2nd or 3rd depending on how far of a run I have. I never use auto 4x4.

This has worked well for me, and after spending a good 15 hours straight behind the wheel on Sunday I can tell you that my coolant temp never budged and my trans temp never went over 180 degrees. 

Good luck.


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## basher (Nov 13, 2004)

The tow/haul mode not only locks out 4 gear it locks up the torque converter. Allowing the torque converter to lock in and out will burn it up. Todays vehicles are so computer controlled they use the Tow/haul to change valve and ignition timing, transmission shift points, and fuel metering. Don't second guess the design engineers, believe it or not they know the truck better then you do. I don't understand how the truck running a higher rpms caused it to over heat. lower RPMs should move less air and less coolant also it will have the engine running in a lean mode causing even more heat as well as poor performance. Keep the Tow/haul on the higher RPMs will also spin the alt. faster creating more electric to feed the plow.


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## Yaz (Apr 13, 2005)

I would not plow in Auto.. this will cause the 4X4 to go in and out. It would be like plowing with a escalade or Denali (not recommended) not exactly but not good...lol
Transporting from one site to another would be OK. Keep that blade as low as possible when going do the road. Adjust it to what keep your truck the coolest. I don't like to angle as it wears tires at highway speeds. I bet the tow/haul is in your mind... lol 

Good luck


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## Bad Luck (Sep 30, 2004)

basher said:


> The tow/haul mode not only locks out 4 gear it locks up the torque converter. Allowing the torque converter to lock in and out will burn it up. Todays vehicles are so computer controlled they use the Tow/haul to change valve and ignition timing, transmission shift points, and fuel metering. Don't second guess the design engineers, believe it or not they know the truck better then you do. I don't understand how the truck running a higher rpms caused it to over heat. lower RPMs should move less air and less coolant also it will have the engine running in a lean mode causing even more heat as well as poor performance. Keep the Tow/haul on the higher RPMs will also spin the alt. faster creating more electric to feed the plow.


The whole idea is that the truck is working harder but not moving more air because of the blade. Tow/Haul does not lock out 4th on 1/2 Silverado's


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## Yaz (Apr 13, 2005)

Your right it doesn't lock out overdrive... I remenber towing my boat and keeping it out manualy in my 1/2 ton.


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## Up North (May 4, 2004)

Yeah, the tow/haul doesn't lock out 4th, at least on mine. I guess my reason for not using tow/haul was to keep my rpms down since the more rpms you have the more heat is generated. But for whatever reason the last time I was out and DID use the tow/haul mode it didn't overheat...but I was also more aware of where my plow was during transport. That was probably my big difference. Anyway, thanks guys.

Buck


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## Bad Luck (Sep 30, 2004)

Up North said:


> ..but I was also more aware of where my plow was during transport. That was probably my big difference. Anyway, thanks guys.
> 
> Buck


Hit the nail on the head Buck.


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