I mean no disrespect but have you towed much before? Reason I ask is that some assume that their truck will or should perform simular loaded and unloaded. But once they hitch up, wow what a difference... and the shock...So I had a truck simular to what you now have. On these small block gas engines, power is found a little higher in the rpm's. The 3.42 is whats killing you on the highway loaded. Trust me I was in the same boat but with a heavier camper. So what I suggest to do is to swap out the 3.42 to 4.10 gears since u have a 2 wheel drive. This will make a difference overall in your trucks abilities. I can tell you a 5.3 with 4.10 gears runs/pulls very well...Best of luck keep up updated.
I had a 05 AV 4X4 with the same drivetrain as yours and towed two different TTs with it both about 5k lbs+. My wife takes everything so that adds 1k or so but never weighted it after she loaded it. Went over the Rockies and back 4 different times. The long grades are slow but running high RPMs on a well maintained engines shouldn't hurt it. Be aware the 05s did not come with a trans cooler even with the trailer package. Don't tow without one. Our new truck has the same basic engine but the six apeed tranny which makes it tow a lot better.
2011 Silverado 1500 LTZ/Trail Lite 8230
I have towed my TT with my 2004 Avalanche in all conditions from mountain passes to the flat lands.
I have to agree with some of the other replies. Your expectations may be set a little high. You are pulling a trailer and just like the 18 wheelers out there-there is no such thing as a quick acceleration. The folks behind you may not be happy about it but do they really expect you to make 60mph in 4.2 seconds?
The Avalanche will handle your trailer just fine. However if you want to hot foot it around be prepared to have a large fuel bill. If you can hold yourself to 60mph you should see 10mpg, after 60 mpg starts to slide.
4000 miles round trip east coast and back I averaged just over 10mpg by keeping my speed at 60. On a trip to Colorado I also averaged just over 10 mpg. It was hard to do, Nebraska is pretty boring to drive across. However counter to what a person would think MPG actually improved in the mountains(slower speeds = less wind drag = better mpg).
If #1 or #2 was the problem I would think you would also notice the same symptons when you are not towing. Though before towing you should try to catch up on your preventive maintenance because small problems act like big ones when the drivetrain is under more load/stress.
I am wondering if you are just expecting a loaded vehicle to drive like an empty one. I know a lot of people say their TV pulls their TT like nothing is back there but that hasn't been my experience. My 06 Explorer is a jack rabbit when empty dusting off unsuspecting cars with its 293 hp V-8 but hook my boat trailer up to it and it is a slow yet steady turtle. The same goes for my 96 Suburban 2500 with the 7.4l vortec but I rarely use full throttle to accelerate or maintain speed on highway.
How was the wind that day? With my TT a stiff headwind can mean I have to cruise out of OD or much more engine grunt needed. It is a definite difference that I can feel.
Here are a few questions:
1) Could the engine be starved for fuel, like a clogged fuel filter ?
2) Could the catalytic converter be partially plugged ?
3) Could the axle gear ratio be changed ? I assume if this was changed the speedometer would need to be modified as well ?
I did look at the factory sticker which does vwerify the exact weight of the trailer when it left the factory and it was about 4700 lbs.
It did pull with no problem at speeds below 50 mph. it was accelerating to highway speeds that had me very concerned, it seemed like the truck was working very hard and didn't think this would be good for the truck long term.
03 Ford Excursion Ltd 6.0L ARP studs/HG, 6.4L banjo bolts, blue spring mod, coolant filter, K&N CAI, turbo back exhaust, IDP tunes, SCT Livewire
00 Acura RL
08 Jayco 31 BHDS G2
96 Regal 258 Commodore
I did take the Avalanche in to be checked out and all seems well with the engine and drivetrain.
From what I have gathered on an Avalanche Forum is that it tows much better running with the gear selector in 3 which raises the RPM's and the torque and that seems to be the golden rule when towing with the Avalanche.
Agreed, I think I am expecting too much from the truck, and yes there was a significant wind that day but I am not sure what direction it was blowing in regards to our driving direction.
Now, armed with a lot of good input, I am going to try in again.
Yes pull in 3rd with the 4L60E tranny, that keeps the rpms up and doesnt burn out OD. Also look into the 4.10 gears..this will help out over the 3.42 gears thats killing your trucks pulling power since you have the 4 speed. You should have no issues pulling that wieght, I have pulled more in my last truck like yours and had no issues..
Lock out OD. The 5.3 is at 90% of torque peak from 2350-4100 RPM. With 3.73s I ran around 60 MPH in 3rd gear to get into the bottom of the power band. With 3.42s you may need to go a little faster, or with 4.10s reach the power band in the upper 50s. That tranny has a tall first gear and seems very slow.
Early 1999 F-350 7.3 DRW CC, 4.10
(retired from towing) 02 Suburban 5.3 3.73
2011 Passport 290BH - Blue Ox Sway Pro
3 Kids, 2 Dogs, 1 Wife.