Towing Question

[dgh5454]

Question regarding towing. We're heading out to the UP in a week and I'll be towing a three place trailer with 3 sleds and gear. I drive a 2005 Chevy Tahoe Z71 5.3 When towing this much weight, what gear to you travel in? Do you use and trust the trailer button on the gear shifter that automatically adjusts the shifting or do you travel in third gear no matter what. Or do you have any other suggestions? I've pulled a trailer many times, but I had my transmission rebuilt over the summer and I am rethinking all my towing strategies, just in case that had something to do with my transmission failing.

Any suggestions are appreciated. Thanks.

 

[simonsr1]

I currently drive and '05 Denali, sometimes I use the Tow/Haul button other times I dont, I think the button just delays the shift a little longer than normall, I always leave it in overdrive, fuel mileage allready sucks, would be a lot worse not in overdrive. towing in overdrive isnt recommended, but I have been doing it this way for almost 20 years and have not had a problem, the overdrive clutch packs aren't as strong as the rest, thats why its not recommended, if your driving along and it keeps shifting in and out of overdrive then I wouldnt keep it in overdrive,

thats my 2 cents.

 

[Dave_B]

You should be fine. I tow a 5,000lb travel trailer with a 2007 Suburban Z71 5.3. I never use the trailer button. I think it shifts much better and revs less without it. Try changing it on the fly and see which feels better
JMO

Dave

 

[tyeeman]

Some of the 4L60E trannies had problems. My father in-law who drives his truck like a granny had his transmission go out at like 70,000, it started slipping then really hitting the gears hard. 2nd & 3rd gear clutch packs had to be replaced.
When I'm towing with my wifes Burb (same engine/transmission) I'll tow in over drive if the load will allow it, if the wind will allow it, basically if it doesn't shift alot other than the occasional hill you'll be fine.
Tow/haul mode really doesn't need to be used unless you are at or over 1/2 of the recommended towing capacity. I believe the owners manual says to use tow/haul when your at 3/4 of the max towing capacity. Personally, when I'm towing 4000lbs + I'll use tow haul.

Going foreward, your GM dealer probably has a service deal that at 30,000 miles you go in and have your tranny flushed and refilled for like $150.00. Money well spent in my book, even if you don't tow heavy often.

 

[t_man]

Depends on the terrain

I leave in OD when on generally flat running.

If I get into hills I hit the trailer button right away to reduce the shifting.

If you are good at paying attention to what your tranny is doing this works fine. If you don't pay attention, or share driving with someone who doesn't (as I do sometimes) just hit the trailer button right away.

Most trailer buttons lock out OD and may delay shifts.

 

[tritonmark]

towing

Alot has to do with what size rearend is in the truck. I have the same 5.3 but with the standard 3.21 or close to it rearend. The 3.71 or 4.10 is better for towing but harder on top end or high speeds. I tow a 22ft. open with 4 sleds with no problems. Talked to the factory engineers in canada and they told me to tow in 3rd with the tow mode on. Works the best from what I've experienced. Also added a cold air intake and exhaust for better milage and a little more horsepower.

 

[booondocker]

Personally, I have towed right up to maximum capacity, which makes me uncomfortable to do it, but have done it for long stretches.

I think that most of these trannies are not really made to do much work in the high load range without wearing them out prematurely.

I don't both with a two up sled trailer but the bigger cargo trailer goes along much better in 3rd gear and forget about the tow haul mode. It just winds out more until it shifts and downshifts faster.

For those who think that it costs more to wind the engine faster, remember that running in 3rd gear matches the load better, and allows the engine to breath better, and cool better. I have had no less than 5 different transmission guys tell me NOT to use overdrive and pull a trailer of almost any size. They see way too many rebuilds not to understand what can happen if the tranny gets hot or the engine is lugging down too much.

I have run with and without overdrive, and you can't really tell mileage difference either way....but it pulls much better in 3rd gear. If I hit a long stretch of flat road and I am pulling less than half the rated load, I shift it manually up to overdrive and cheat some. Of course I don't try and blast along either...fully rated loads, or over 4,000 pounds, I find that there is a huge difference in mileage and engine work trying to go over 65 mph. This is the sweet spot on my truck....pulling load with same basic GM engine and drive train.

 

[dcsnomo]

From the owners manual-

Tow/Haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75 percent
of the vehicle’s Gross Combined Weight Rating (GCWR).
See “Weight of the Trailer” later in the section. Tow/Haul
is most useful under the following driving conditions:
• When pulling a heavy trailer or a large or heavy load
through rolling terrain.
• When pulling a heavy trailer or a large or heavy load
in stop and go traffic.
• When pulling a heavy trailer or a large or heavy load
in busy parking lots where improved low speed
control of the vehicle is desired.
Operating the vehicle in Tow/Haul when lightly loaded
or with no trailer at all will not cause damage. However,
there is no benefit to the selection of Tow/Haul when
the vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/Haul is recommended only when pulling a heavy
trailer or a large or heavy load.

I use tow/haul with a three place trailer as it keeps the transmission cooler...my Silverado has a trans temp readout. From another section in the owners manual...
Vehicles with an automatic transmission have a tow/haul
mode. The tow/haul mode adjusts the transmission shift
pattern to reduce shift cycling, providing increased
performance, vehicle control, and transmission cooling
when towing or hauling heavy loads.

 

[arctiva]

I had a 2001 5.3 silverado allways towed 3 sleds in 3rd transmission never downshifted in hills set cruise control wherever i wannted normall 75 and got 11mpg regulary. If i recall i think it ran around 3500 rpms at 75.

My old man had a 2001 5.3 gmc and pulling same 3sleds and trailer trying to nurse it along in overdrive doing 65-70 mph constantlly down shifting in hills or any little incline averaged 12 mpg. When his truck downshifted he was in the 4500 rpm range if i recall. My dad now has a 2009 silverado 5.3 and everything is about tha same power/rpm/mileage pulling the 3 sleds.

I say do your truck a favor and run in 3rd. The constant down shifting and spike in rpm's i would think will do more damage than a constant rpm and no down shifting.

The Tow haul button does you absolutlly nothing once your above 50 mph or your in 5 th gear. All it does is hold the gear longer and run higher rpm's 1-4th gear. Push the button running 65 mph with the trailer and you will see it does nothing. When your truck shifts out of over drive on a hill push the tow haul button and once again you will se it does nothing.

The 5.3 is a crappy tow engine in my opinion under powered and rev's like a mad man

 

[dognvenus]

The biggest killer of trannys is overheating. An added tranny cooler doesn't take a rocket scientist to install and adds extra cooling capacity plus extra fluid to the system.
Many trucks that have trailer options from OEM still don't have coolers, just the hitch and lighting installed. If towing on a regular basis, getting the filter and fluid changed every year or every other year (depending on your use) is a good idea also.

Dog