Chevy - Tow/Haul mode

[Roger Chambers]

After seeing Teri's post, I have a question. My 2002 Chevy has a tow/haul mode. The manual says when pulling of hauling a heavy load to leave it in overdrive and engage this mode. In this mode the transmission does not shift from drive to overdrive as often but it does still shift quite often (using cruise). I can pull in overdrive, not using cruise, and make it make it rarely shift from overdrive to drive. Should I pull using the tow/haul mode, in overdrive without cruise or in drive (3rd) only.

 

[Scott Hammer TOXIC]

First, don't tow in cruise unless it is a log flat stretch. Put it in tow mode if your tranny is constantly up or downshifting. That is the killer for trannies, the "hunting" that they do. You want constant gearing. I switch in and out of tow mode (called OD Override on my Explorer) as needed and I NEVER tow with the cruise on.



TOXIC

 

[Teri C.]

You don't even tow in cruise on a long stretch of highway?

 

[Scott Hammer TOXIC]

Nope. I fried a tranny once and the mechanic (a friend) told me to never tow in cruise. It may be ok, but I now have a mental block against it. Cruise also does not let you do the speed up on the downhill side to climb the hill side. It will just downshift to get the rpm's up. I have found that it doesn't take much of a grade to get cruise to downshift. Better safe than sorry for me.



TOXIC

 

[Roger Chambers]

Tox, how often do you change your trans fluid? I've had trucks with up to 170,000 miles and never changed the fluid. Although, on this truck I did install an aux. trans cooler since I am towing the boat and it's only a V6.

 

[Michael Snow]

I had a 2000 v-6 chevy with an 18' Xpress x-56 with 115hp. I towed it in cruise. It wouldn't take the 20' Nitro, so I upgraded to the 5.3L v-8 (2003 model). I tow with cruise on it. I do use tow/haul mode.



Yes, it does hunt, but I've got the factory upgrade tranny cooler. The first truck had 35k and this one hasn't hit 5k yet.

 

[TOMMY RICH]

If your not pullin' a big glass rig on hills...I use Overdrive when it's flat but, then again my rig only weighs less than 2000 lbs. Just use common sense...you'll be allright. I do agree with the tranny cooler though...

TEE

 

[Teri C.]

I only tow with cruise on long flat stretches of highway when my foot is cramping up from being on the peddle for so long. I always shut the cruise of when driving up and down hills on the highway. I usually never go more than 70 when towing. So, do you think I made a bad choice for a tow vehicle? I would love to buy American but the last 2 SUV's (Ford and Chevy) did not hold up very well.

 

[Jim B]

I personally dont like towing in overdrive. it makes the tranny run hot, even with a tranny cooler. from what im told by a tranny guy, in od when the torque converter locks up the fluid get redirected in the tranny bypassing the cooler making it run hot. he suggests always towing in whatever gear is your 1:1 ratio, third of fourth depending on if you have 4 speed overdrive or 5 speed overdrive. He also mentioned downshifting causes alot of heat and to much tranny hunting will kill the tranny. When i had my GMC i towed with the od on and tow haul on and i smoked a tranny because it was downshifting way too much. I wont do that again. With my current Dodge i tow with the od off. When i ordered mine i calculated out what gear would be best on the freeway where i tow. I had two choices 3.55 or 3.92, i went with the 3.55's because they keep the rpm right ar 2300 at 65, the 3.92 would almost force me to use overdrive because it would rev too high for my liking. The truck never needs to downshift ever, i tow mainly in hilly terrain.



R. Chambers take a look in the owners manual for tranny service intervals. There should be a listing for how often to change it if you tow frequently. On my last GMC it stated every 15k. You may also want to look into a full system flush every other service.



Teri

I think you made a fine choice with your new suv. the only thing i dont like about those is the unibody, theres nothing wrong with them its just not my first choice for towing. I prefer a full frame vehicle. I know a few people who own the pathfinder variant of your infinity and they really like them. One of me peers at work has one that he tows a camper with and he says it does very well with it. He tows about 3500 pounds. One thing you may want to do is try to keep your speed around 65 on the freeway, it will work the truck a little less hard and you will use a little less gas. my truck uses about 2 mpg more going from 65 to 70 and if i push it over 80 it goes into the toilet( <10). How do you like that Bose audio system that comes in those?

 

[Bob G.]

Roger,



I also have a Chevy and tow in Tow/Haul Mode and in 3rd gear. The tow/haul mode increases the shift points for each gear and winds it out longer before shifting. It makes it easier getting up to highway speeds when merging.



My belief is that towing in OD is a tranny killer if you are not on long flat stretches of highway. I used to have an 88 GMC 2500 that I bought used at 53k miles. The previous owner towed a camper in OD. I had the pleasure of having the tranny rebuilt twice and then got rid of it.



I think my Chevy manual calls for transmission fluid/filter replaced at 50k when towing, I'll have to check. My last truck was a Dodge Ram and given their reputation, I had the tranny fluid/filter done every 12k miles, the manual called for every 36k miles.



Bob G.

 

[Scott Hammer TOXIC]

I do the tranny fluid every 30k in the explorer (which has the cooler and 3.73 gearing and 97k). My shop told me that there is no need to do a new filter since the newer ones can be flushed with the right equipment.



TOXIC

 

[Roger Chambers]

Thanks for the info and opinions everyone.

 

[TOMMY RICH]

Worms??? We have enough for everybody! Glad that's over..

TEE

 

[Wade Dunn]

Well fellas, there are a lot of rumors running around out there about towing in OD. Your tow haul switch signals the vehicles PCM to stay in gear a bit longer before upshifting and also changes the shift firmness (only when a load is being pulled) Almost never noticable from the drivers seat unless other perfomance mods to the vehicle. It is never a good Idea to leave in OD, but this mostly depends on conditions, weight of boat, ect, hilly country or flats. Regardless if you put any additional weight in a pu, the trans is what takes the abuse. Most haulers use the rule of thumb, If on flats, your trans wants to downshift several times in a 5 mile stretch, leave it in 3 gear on a auto and 4th on a 5 speed. And as for any Dodge owners out there running a automatic trans you can pull in OD all you want, It has been proven the 46 or 47RE trans you are running will go out before anything else does!!! Just giveing you guys a bit of crap. But for you dodge guys out there, most automatic trans have a check valve in the line near the radiator, that does tend to plug up. Keep an eye on this, this check valve has contributed to many trans failure, do to insufficent fluid flow.