Chevy Z71 Trailer Towing Question

[Sambone]

I have an '01 Z71, 5.3L and my boat, trailer, engine, misc weighs 3500lbs

The transmission has a towing setting (push a putton on the end of the gear shift) which obviously takes it out of OD. Should I use this everytime I tow? Even long distances? The thing stays in 3rd the whole of the trip (on the hwy) and sometimes stays in first or second gear a long time if I'm in traffic. The RPMs aren't to bad I guess, still stays under 2500 RPM, even at 70, but it is annoying and I wonder what kind of havoc it reaks on the engine. It's probably that I'm used to the quiet ride with the tranny in OD most of the time. I just had the tranny rebuilt and don't want to tear it up.

Anybody answer this with knowledge on the subject?

[Skeet'r89]

Need to ask a question.
Does your shifter have 1,2,D,&OD. I don't believe that the Chevy,s drop out the overdrive with the Tow/Haul switch. It should only change the shift points and lockup pressure in the transmission. In the owners manual of my 2500 it states that the Tow/Haul setting is not needed until towing about 75%(If I remember correctly) of the max tow capacity.If you are on a fairly lever road at a steady 60+ mph it would probably be fine in OD. If your are in rolling hills and the trans is searching up and down alot you woulod probably want to stay in D(3rd) and possibly use the Tow/Haul setting.
Does your vehicle have a trans temp. guage?

[Sambone]

The shifter shows PRND321. The truck weighs 6400lbs...and it does have the Towing package on it. I bought it new, best dang truck I've ever owned, and I've owned ten or twelve. I don't really know the towing cap, I could look in the manual I guess (I think it's still in the glove box) But I know for a fact when the Tow Haul switch is pushed, if I'm D , 4th gear, it downshifts immediately to third. But about the flat surfaces...that's a rare thing, when in normal Drive, it will constantly shift back and forth on the rolling hills.

I guess setting the cruise control is out of the question too, huh? I've towed up to 300 miles and never had any heat issues at all. And no, although I'm all guages with no dummy lights, but there are no transmission temp guages.

[Skeet'r89]

On your dash cluster does the D have a big O around it. that would be Overdrive. I was pretty sure that in tow haul that it will still go into overdrive if the conditions are currect. Mine runs in the OD setting an rarely have it set anywhere else. Most of my trailering trips are less than 30 miles.

[ch]

It might not be a bad idea to visit with a GM tranny tech about this Sambone cause like Skeeter89, my 01' & 03' i used to have & the 04' i have now all will go into overdrive when the "tow-haul" button is pressed. It just takes it a little longer to shift thru the gears (the shift is at higher rpms).

[JR19]

When tow/haul feature is activated the transmission will shift into every gear including Overdrive.

When the button is pushed in the two/haul is activated and the computer on your truck changes the rpm range in which the transmission shifts and applies more pressure to the fluid in the system.

It also changes your down shift RPM and shifts much quicker than if you had it off.

If the transmission is making a lot of downshifts and your shift selector is in Overdrive you can pull the gear selector down into the next lowest gear selection (without going and looking at my truck I think that is 3rd)

As an experiment/test the next time you are NOT pulling a load get in your truck and engage the two/haul feature. without a load behind the truck you can fell how much harder the transmission shifts and will notice that the RPMs on the shift points have increased. You do not notice it as much pulling a load because the weight is pulling you down.

I recommend if you are pulling a load use two/haul and put the gear selector in OD

[Sambone]

Thanks man. That's exactly what I've been doing. I leave it in D (there is no "O" around it) and hit the Tow/Haul button.

If I'm driving along in D at say 35 - 40 taking it easy and I push the Tow/Haul button it immediately shifts down to third, no matter what. And Even at higher speeds, it stays in third unless I push the Tow/Haul button (to turn it off) then it will go back into 4th or D. I guess what I'm trying to say is, when in Tow/Haul mode, the highest gear it will shift into is 3rd, no matter what speed I attain. It's always done that since day 1. It's just annoying, driving 200 - 300 miles in 3rd gear at 65 - 70 mph. The Flow Masters are humming....

[LookOutForShoals]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sambone &raquo;</TD></TR><TR><TD CLASS="quote">Thanks man. That's exactly what I've been doing. I leave it in D (there is no "O" around it) and hit the Tow/Haul button.

If I'm driving along in D at say 35 - 40 taking it easy and I push the Tow/Haul button it immediately shifts down to third, no matter what. And Even at higher speeds, it stays in third unless I push the Tow/Haul button (to turn it off) then it will go back into 4th or D. I guess what I'm trying to say is, when in Tow/Haul mode, the highest gear it will shift into is 3rd, no matter what speed I attain. It's always done that since day 1. It's just annoying, driving 200 - 300 miles in 3rd gear at 65 - 70 mph. The Flow Masters are humming....</TD></TR></TABLE>

Everything you say is normal except for the part of it not kicking back into drive. My truck when I have tow/haul engaged (I always use it when towing) won't kick into overdrive until I go about 60 mph but as soon as I do it drops in and goes. It even did when I towed my car (about 6000lbs), it stayed in OD almost the whole trip....

[kyG3]

You need to check the owners manual. If I remember correctly, the tow/haul mode is only to be used if the load is = to 75% of the rating. eg- if the rating is 10,000lbs the load should be 7,500lbs to use the tow/haul mode. I'm pretty sure that's correct, but please check the owners manual to be sure.
Mike

[Jig_Man]

I had a 6 litre Chevy gasoline engine and the service guys at the dealership were emphatic about me using tow haul with my 3500 lb rig. When I bought a duramax the said I needed to keep an eye on the boat because I'd forget it was back there and the duramax would never know it was there.

Use your tow haul.

[adchunts]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kynitro482 &raquo;</TD></TR><TR><TD CLASS="quote">You need to check the owners manual. If I remember correctly, the tow/haul mode is only to be used if the load is = to 75% of the rating. eg- if the rating is 10,000lbs the load should be 7,500lbs to use the tow/haul mode. I'm pretty sure that's correct, but please check the owners manual to be sure.
Mike</TD></TR></TABLE>

I use the tow/haul mode on my '06 Z71 Crew every time I tow. I actually get better fuel mileage than not using tow/haul mode. I did a lot of experimenting with towing in T/H mode versus not. Of course, that's just my personal experience.......

[LookOutForShoals]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kynitro482 &raquo;</TD></TR><TR><TD CLASS="quote">You need to check the owners manual. If I remember correctly, the tow/haul mode is only to be used if the load is = to 75% of the rating. eg- if the rating is 10,000lbs the load should be 7,500lbs to use the tow/haul mode. I'm pretty sure that's correct, but please check the owners manual to be sure.
Mike</TD></TR></TABLE>

I have towed with a vehicle that was approximately 50% its max load, and if you didn't use tow haul the tranny temp would run approximately 20-30 degrees hotter, than if you had tow haul on. So that told me that I should be using tow haul....so I use it whenever I am towing anything smaller than a light load.

[Sambone]

Thanks guys for all the info. I'm pretty sure that the highest gear attained ever in T/H mode is 3rd. Even when it was new. That's strange that everyone elses shifts into 4th. I bought it new in 01 and just paid to have the transmission rebuilt ($3K) and I know for a fact 3rd is as high as it goes in T/H now.

Ya know I thought that was strange. At 65 - 70 the rpm's coupled with the flowmasters drive me nuts! I'm going to take it back to AAMCO and have them double check it before warranty expires.

I just wonder what kind of bunk they're going to give me....

Thanks again...

[kyG3]

To each his own, That's just what they said in the GM 4L60E training class. As I said read the owners manual. GM wrote it and they're the people that have to warranty the trans.

[spotslayer]

If it is not going into OD with no throttle input then something is wrong with your transmission / torque converter

It's basically like having a shift kit in your truck when you need it. Towing a 3500 lb bassboat you don't need it. hurts mpg

have never used it on the 6 GM trucks/SUVs that we have owned

Listen to the tech he knows what he is talking about

BTW your truck doesn't weigh 6400 unless you have a half ton of sand in it

[Sambone]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spotslayer &raquo;</TD></TR><TR><TD CLASS="quote">If it is not going into OD with no throttle input then something is wrong with your transmission / torque converter

It's basically like having a shift kit in your truck when you need it. Towing a 3500 lb bassboat you don't need it. hurts mpg

have never used it on the 6 GM trucks/SUVs that we have owned

Listen to the tech he knows what he is talking about

BTW your truck doesn't weigh 6400 unless you have a half ton of sand in it </TD></TR></TABLE>Good information man, appreciate it, and you're right, 6400 lbs is the GVWR (maximum combined weight when loaded)

I can't find what the actual weight of the truck is, the manual says take it to a weigh station for accuracy. Doh!

So you're saying just use the Drive seeting, like normal, when pulling 3500lbs? I have to admit, that does seem to work out unless going up and down hills and inclines. Also, I was wrong about it not shifting into 4th in T/H mode, I tried it on the freeway and it does. I couldn't believe it. I don't know why I was thinking that it didn't. But, without a load, in the T/H mode it did shift into 4th.

I will just keep it in Drive from now on. Again..thanks for taking the time to explain.

[spotslayer]

We have some hills around here so I dont use cruise control and drive like I have an egg under my foot

Try and keep the truck in OD by letting it coast up the hill even if it means dropping down to 55 mph, keep rpms around 2000-2200 for best MPG

I get around 13.5 driving this way Z71 3.73 with LTX tires and a 21X loaded

Truck wt is around 5200-5400 depending on trim level and accessories

Ford's TH takes them out of OD

[SwatDawg]

I have a 1998 3/4 K2500 with the bigger 4l80e tranny. I lost O/D the other day and took it in. They rebuilt it, and told me to haul my boat in 3 instead of O/D. I don't have that tow/haul button I have PRND321. I also have flow masters and when I lost my O/D I ran 70mph 3200 rpms and they were annoying also, I think more of a mind game . Anyway, they also told me if I went "mud hogging" witch i don't do, keep it in 3. Seems to me the O/D is not that strong in Chevys??. My truck just rolled over 100K in January, and I love it, would not get rid of it for nothing. I guess I will deal with the flowmasters hummin to keep from paying another 2k for a tranny rebuild

[Sambone]

Thanks guys. I love my Z71. Like I said, I bought it new and it has been the best truck I've ever owned. I've went to trade it in twice and at the last minute I just couldn't do it. Now it's to late I guess, I just turned over 206K and it still purrs like a kitten. I'm actually getting the two front seats re-upholstered tomorrow. It's all leather and the Drivers side is torn at the seam and the arm rest is cracking. Well, I said leather, it's Chevy's "version" of leather. I'm going back with the same. $600 to completely do both seats. I thought that was cheap. The guy that's doing it is my son-in-laws dad, he's supposed to be well known and has customized interiors for hundreds of trucks. We'll see.

[LookOutForShoals]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kynitro482 &raquo;</TD></TR><TR><TD CLASS="quote">To each his own, That's just what they said in the GM 4L60E training class. As I said read the owners manual. GM wrote it and they're the people that have to warranty the trans.</TD></TR></TABLE>

Only for the first 36000 miles.