Towing mode on chevy trucks.

[streetrod77]

I have to start moving the PT car around to different shops to get somethings done. I have a 16ft trailer for this purpose. A guy at on of the shops said that I can tow the car without turning on the tow mode because there are no hills to go up or down here. He said that evan with the overdrive on, the truck has enought power to tow cars fine. Is this true? I notice a few of you have chevy trucks on here that you tow with. I was thinking maybe if the tralier was empty it didn't matter but I'm not sure about that either.

[ProdigyCustoms]

There is no good reason NOT to use tow mode, but with that said I can tell you I have accidently towed LONG distances without using tow mode.

[Samckitt]

I have a 1500HD with the gas hog 6.0L & I have towed without using the tow mode. From what I have been told, the tow mode keeps the torque converter from locking to form a direct link between the two, resulting in a little more torque when it is needed. If on some hilly roads this might keep the tranny from down shifting as frequently to get more power.

[streetrod77]

I think I may have turned the tow mode on once and it felt scary. It was not smooth at all.

[surlyjoe]

I generally don't use tow/haul mode but it is good if there a lot of hills. It changes the shift points slightly higher. I do watch overdrive though if you are under 50 mph and it shifts into od that can be hard on the transmission. So my solution is when in town to keep it in drive.

[Vegas69]

One thing you guys are missing is it may increase the line pressure as well. (More hydraulic force on the clutches) Same thing with manual first on a TH350 and TH400 I believe. I have been out of the business for quite a while but this is definitely how things worked some years ago. It is very conceivable that the new trucks sense the load and adjust and add line pressure on there own to keep people like Frank from roasting there tranny pulling a 26 ft trailer across the United States without Tow Haul mode on.:lmao:

[parsonsj]

I always use Tow mode on my Duramax/Allison 2500. Well... as soon as I notice I forgot to turn it on, I mean. That's usually within 50 miles of when I start, lol.

jp

[brownz]

i have a 2006 2500hd and i use mine just seem better to me

[LMDGUY]

I use "tow mode" when ever i tow with my Dodge. My tech say it increases line preasure and bumps up the shift points.

[GetMore]

It is not a requirement, but it will help the tranny live longer.
It holds gears a little longer so it won't shift quite as much and does raise the line pressure. Yes, this does make for harsher shifts.

[streetrod77]

That sounds about right. I hate the way it feels but if it's a go thing, better keep doing it.

[parsonsj]

One more thing: on my Duramax, tow mode also enables engine braking when going down hills. It's probably just a diesel thing ...

jp

[Vinz68]

I have a 1500 chevy and i use tow mode when trailering my car. I reacently bought a 24' inclosed. I'm a little nervous how my 1500 will handel it. The truck tows great with an open trailer. Thank God for warrenties......lol.

[class67]

I always use it, though it drags the shifts out a little and doesn't feel smooth, I'm sure it helps when towing with my Chevy 1500 crew cab.

[68sixspeed]

if you are towing an open trailer or something light (snowmobiles), I will kick it out of Tow mode on the highway if it is level and easy going just to let the converter lock in and the rpm drop a bit.

[Shawn MacAnanny]

I have an 01 Duramax and Tow/Haul is my best friend. The grade braking is the best feauture Chevy ever came out with. I've towed loads well over 20,000lbs with my truck and the trans temps NEVER got over 200.

A few times tow haul has helped save me from a few narrow accidents like when making a Uturn towing one of our cats (12klb with trailer) the plug came unhooked and i lost trailer brakes at the next stop light. Engine just downshifts and locks converter to help slow the load. Another time i had the tensior puller snap and i lost power steering/brakes (run from the PS pump) and with the grade braking and trailer brakes stopped the load.

With the tow haul mode you notice the difference more on the highway between normal mode and such. I can tow my 28footer (10klb loaded) at 75 mph fine in 5th gear tow/haul but when going up grades and such you'll fine it skips back and forth in normal mode between locking and unclocking the converter and shifting to 4th.

Tow/haul enables the converter to lock up at a lower rpm to reduce transmisison temperatures plus give added torque to get loads moving. It also adjusts the shift points to higher rpms so when the transmisisons shifts the next gear is right at the start of the powerband. The computer also learns driving habits and such for each tow/haul and normal mode. I always tow in tow/haul and all regular driving is in normal so all my grade braking setting, upshift, downshift, and converter lock settings stay constant.

[nvr2fst]

One thing you guys are missing is it may increase the line pressure as well. (More hydraulic force on the clutches) Same thing with manual first on a TH350 and TH400 I believe. I have been out of the business for quite a while but this is definitely how things worked some years ago. It is very conceivable that the new trucks sense the load and adjust and add line pressure on there own to keep people like Frank from roasting there tranny pulling a 26 ft trailer across the United States without Tow Haul mode on.:lmao:

Your thoughts are correct. For GM the higher upshift speeds and firmer gear changes are due to an increase in line pressure. The original intent of the T/H mode was designed to tow a load 3/4 or more the rated capacity of the truck to prevent/reduce slippage (heat build up) on the trans.When engaged it changed the shift points so the engine can rev higher or opposite on the down shift locks up your convertor sooner. I have not looked at a ford truck in years but back when i had one it had "adaptive learning stategy" (no t/h mode or any other button. The tranny was suppose to know when i was carrying/pulling a load and adjusted according. Not sure what there doing know.
dave
keep in mind what u can pull you better be able to stop TRAILER BRAKE dont learn the hard way like i did it may cost u.

[cad]

When I towed my open H&H trailer I never knew the car was behind me.
Now I tow a 24ft enclosed with my 68 Camaro and a ~650lb golf cart in the front of it with my 2001 K1500. I have a friend who is a Chevrolet transmission specialist. Here is his quote..."ALWAYS use the tow mode when towing".
Anyways, I have never had a problem (knock on wood), nor has another friend who tows a heavy 24ft H&H with a big block Malibu in it with his 2002 C1500.

[nekkidhillbilly]

it doesnt disable od in th mode by the way just locks the converter

i use it

if you hold in the th button it will lock out od but just mashing it dont

[Shawn MacAnanny]

Enclosed trailers are always more unstable at highway speeds. I usually always load to have atleast 1200lb tounge weight to avoid swaying with wind sheer

[MonzaRacer]

Ok tow haul mode changes the shift algorithum, algorithum on line pressure is modified and the torque converter locking strategy is modified.
It raises shift points/quality and it also has the trans temp monitor set for spikes/rises in the temps.
Remember the older non electritonic trans had athrottle valve (TV ) cable to raise line pressure, in electronic trans its controlled by PCM/TCM.
See the theory is thatthe less pressure it NEEDS to produce the less load on the engine and hence better economy. also to keep the TC clutch from burning the converter up it make sure the vehicle is up to speed, throttle is closed and engine load is at a lower level befor locking the converter.
Figure it this way if your accelerating the converter clutch has to stop parts rotating, deal with extreme temps and if the load it too high the converter clutch burns instead of locks, ALSO it will keep the converter locked longer till the program figures the trans need the added torque multiplication to say climb a hill or pass.
If you dont use it you will cause damage in the trans, but that is up to your wallet.
figure this if your pulling within half of the rated max vehicle capacity I would run it. This doesnt mean run it if you have 1000lbs in the bed for short trips but iff your going several hundred in variable terrain I would kick it on. A 4 wheeler or snow mobile well I really dontthinks thats enough to worry about unless over the 20-30 minute in stop and go driving, freeway regular mode would be ok as the trans get to stay at proper temps.
ALSO buy the largest cooler you can afford/fit and make sure it has one of the bypass/thermostats that allow the fluid to bypassthe extra cooler and only go through the rad.
ALSO run it through the aftermarket cooler and then the rad, @ reasons, this will allow the fluid to cool even back to a lower temp than the 170-200 range, then if you have over cooled it the coolant will heat it back up and keep fluid at a propertemp.
Id its too cool it wont work well and the additives are heat activated.
also the newer Dexron IV and Ford Mercon V are much better fuilds and I actually prefer full synthetics. Mercon V should be full synthetic if not its a "doped" Dexron/Mercon mix and not as good. I havent actually see all of the requirements of the new Dex IV but all of these fluids are rated for backwards fitment.
My preference so far have been to bypass all the "pour in" make it the new stuff from BG and other.
There is one company Lube Guard and thhier products have so far far exceded my expectations but a make fit is still a make fit.
B&M, Mobil, Redline, and Royal Purple Synthetic fluids have impressed me greatly.
Synthetics lubes are not any black magic simply ENGINEERED base lubricants, still made from crude and crude by products. Engineered for thermal stability and such.
Anotherthing is if you have tow vehicles take them in in the fall and have them flushed and dont be stingy with fluid $50-$75 in fluid every year is better than $1000-$4000 in trans repairs/rentals in my book.
My preference is filters is every 25k to 30k. you simply have them flush it, then drain with the machine(less mess for them and you) drop pan and filter then top off to proper level.
Maintenance is much cheaper than breaking cause it will break at the very worst times.

[348-4speed]

I have 2500 HD with the 8.1 (496ci). I do a lot of towing and use the tow/haul mode most of the time unless my trailer is empty and I am going for a short haul on flat ground. Good Luck

[dcozzi]

One more thing: on my Duramax, tow mode also enables engine braking when going down hills. It's probably just a diesel thing ...

jp


Mine downshifts as well as shifts later.

I wonder if by delaying the shifts, it keeps you under boost, and as a result, lowers EGTs while towing too. Complete speculation here.

My truck seems to have higher EGTs when just accelerating up a hill under fueling rather than boost (bottom of the gear). A little RPM induced boost (middle of the gear) seems to bring lower EGTs as well as the obvious effortless pulling ability.