Any Truck Mechanics

[Bobby McCarley]

I bought a new 2009 2500HD Chev truck with a six speed auto 6.0 engine in March to replace my old truck which was a 2000 Chev 1500 with a 4.8 engine. I pull a 24 ft. light weight camper with my truck and the old truck pulled it fine, but we have been thinking about getting a bigger camper, so I wanted to get a bigger truck with more pulling power.
Now, the problem, on the old truck I could set the cruise control on 70 and it would never miss a lick unless I was on a steep incline. On the new truck I can not use the cruise control because it will not hold the speed. The speed starts dropping off and the passing gear kicks in to get the speed back up to 70. Then it starts drifting down again and the same thing happens again, the passing gear kicks in. This happens about every 1 to 1 1/2 minutes. I take it in to get it checked out and guess what, they can't find anything wrong. Their comment was, that this a different truck and engine and trans. and that I'm just not use to the the way it handles towing something.

My questions is has anyone experienced this problem or heard of this? I would think this bigger truck and engine would run circles around the lighter 1500 truck.

Any comments would be appreciated.

Bobby
Louisiana

[Dan Hintz]

what happens if you set it to 75? Maybe you're not in the sweet spot for that particular tranny...

[Jim O'Dell]

The main difference is the 6 speed trans. It is going to try to keep the load of the engine in the sweet spot. So as the vehicle slows slightly, it drops to another gear. This is for fuel mileage issues. It is rather disconcerting, but rest assured, it is a normal situation for that type of trans. Does your's have the "tow haul" switch? You might try using it, but you will probably notice a drop in fuel mileage. The 6.0 engines are not known for their good fuel mileage anyway. :eek: Jim.

[Jerome Stanek]

Are you using the trailer towing setting on the tranmission?

[Faust M. Ruggiero]

It' may be a bit late now but if you tow on a regular basis you might want to consider a diesel engine. We run several in our business and the diesel engine is combined with an Allison transmission. The combination makes towing a real pleasure.
fmr

[Bobby McCarley]

Thanks for the comments, they are appreciated.
The truck does have a tow/haul feature and I was in that mode while hauling the trailer. I took it off tow/haul and it still would not hold the speed with the cruise control on. In fact it will not hold a constant speed with the tow/haul on or off and it will not hold the speed using cruise control or with the gas pedal and foot control. The speed drifts and the passing gear kicks in to pick the speed back up.

Also another problem is when slowing down to stop, when it gets down to around 25 or 30 mph, it downshifts super hard, the rpm's go crazy, and the engine revs up.

As stated, the 6.0 engine is not noted for its good gas mileage, and this has got to be making it worse. I am willing to trade off gas mileage for better towing capacity, but not with the problems I'm experiencing with truck.

Bobby
Louisiana

[Dave Lehnert]

Just to stir the pot.:)

Should have got a Ford.:D

[Jason Roehl]

First off, you really shouldn't be towing at 70 MPH. It may get up to that speed just fine, but it's the maintaining control and stopping in an emergency situation that are the buggers. A 3/4-ton truck can get pushed around pretty quickly by an out-of-control trailer, and you need to remember that a doubling of your speed quadruples your kinetic energy (and stopping distance).

Second, what are your shifter options? (P R N OD D...) Tow/haul mode on many trucks simply changes the up/downshift strategy. With a 6-speed automatic, either 4th or 5th gear will be the 1:1 gear ratio, and that will be the gear you should be using if the tranny is "hunting" in overdrive.

You definitely don't want the tranny to be constantly shifting like that--it will burn up in pretty short order.

Oh, and I'll second the Ford. ;)

[Bobby McCarley]

While towing at 70 may seem fast, believe me, on the interstate you are the slow one, and that can create a bigger problem than going 70. If you develope problems pulling a trailer, it won't matter what speed you are going, it will probably not be good.

Jason, in this particular truck the shift options are P R N D M+, where in the M mode you shift the gears manually by pushing a +/- button. I have never seen this option on a truck before this one. On my old truck I had the shift options that you indicated and you used the D option in the tow/haul mode, you did not use OD while towing.

And, I have already own a Found On Road Dead, and my experence with it or the dealership, were no better than what I am going through now:D

[Jason Roehl]

Do you have an owner's manual? There's probably something in there about towing for your particular truck. The bottom line is that if the tranny is hunting, you have to keep it out of top gear, or it will overheat your tranny. It might not hurt to install (or have installed) an auxiliary tranny cooler anyway.

The speed limit in most places for tractor-trailers is 60 MPH, with good reason. With a trailer on your truck, you're really more in their weight/handling category. I've gone long distance on the interstate at 55 MPH towing something way heavier than I should have. People just go around you. Your fuel mileage will also improve quite a bit, but if you're really concerned about that, get a diesel (though you probably won't save any money once you pay the premium price for the engine and for the more expensive diesel fuel).

I also wouldn't worry about the hard downshifts--those are helping you get the truck/trailer slowed down, and the engine revving up is just doing its part with the subsequent engine braking.

[Kenneth Hertzog]

Bobby
I have a 3500HD with the same motor and trans.
the rear axle ratio is 4:10
I have pulled a 32 foot camper as well as my 14,000 gvw
flatbed loaded and I have found that using the manual
selection is more efficient than the auto mode when loaded
when going up a hill I down shift one gear just to maintain speed
also found this helpful when on back roads
my last truck was a 2500 silverado with a 6.0 and auto trans
and it worked like you said
the new one is a different breed.
any questions ask away and I hope I can help
ken

[Chris Damm]

Towing in overdrive is not recommended. Try it in drive and see what happens.

[Paul Ryan]

Towing in overdrive is not recommended. Try it in drive and see what happens.


This is why they have "tow/haul" buttons now. I dont have any advise than what has already been aired. But by no means buy a Ford. It should have been a DODGE!

[James Rambo]

I have an 2003 silverado 1500. It has the tow/haul button and it does the same thing. My old camper was a 16 ft. and weighted 3500 lbs.. my new one 21 ft and 3200 lbs. and the truck will not stay in OD. It does not have the option to be in Drive. Last week end we went only 35 miles to camp.The truck, in tow/haul mode went from OD to 3rd gear the entire way (I-75 at 60 mph). I have searched many a internet forum to find a solution. Power programmers and wind deflectors. Some say they work some say they don't. I am going to try a different technique and put the wind deflector on the truck tool box at the rear of the truck bed on the next trip, to see if that makes a difference. I can deal with being in 3rd gear, but I hate the 6 mpg difference in mileage over my normal 650 mile trips.

[Cliff Rohrabacher]

I bought a new 2009 2500HD Chev truck
somethign about government running that show springs to mind.


on the old truck I could set the cruise control on 70 and it would never miss a lick unless [...] On the new truck I can not use the cruise control because it will not hold the speed. [...] Their comment was, that this a different truck and engine and trans. and that I'm just not use to the the way it handles towing something.Yup, you bought a Government Motors truck. All promise and no work.


My questions is has anyone experienced this problem

It happens every single time and like clockwork on the day after the election.



Any comments would be appreciated.you must not be associated with my senator's office. Those people don't want to hear any comments.


All kidding aside, I think you are being given a run around by people whose interest is solely the money you handed them.

I think you might try advocating more forcefully with management but that in the end you will be blown off and worn down by a well practiced pattern of tricks and skills all designed to make you go away.

My best advice is: don't bother trying any more. You did your due diligence and gave then the opportunity to fix it or make you right.
I think you need to take them to court.

[Leo Graywacz]

When I got my 2007 2500HD the transmission shift points sucked. Without a load on them the tranny was clueless. I started using the manual mode. Brought it in and complained.

They reprogrammed the shift points and it was like night and day.

They should be able to do the same for you.

[Jim Koepke]

The best comment I have heard on such a problem when the dealer says that is how they all work.

Then they are all wrong and need to be fixed, you can start with this one.

jim

[Brian Elfert]

Towing in overdrive is not recommended. Try it in drive and see what happens.

A vehicle with a large enough engine and a decent tranny cooler can tow in overdrive just fine. It is when you get into a vehicle that is constantly shifting in and out of overdrivwe where you get into issues.

I had an F-350 with diesel engine towing an 8,000 lb travel trailer. I checked all the manuals and so on and never found anything that said not to use overdrive when towing. The truck when towing would never shift out of overdrive except on the steepest grades.

Some of the newer transmissions have two overdrives with different ratios. Maybe the truck is shifting into the lower overdrive?