Tow vehicle (first post by the way)

[Dave_Monica]

Originally Posted by inspireart

Latest literature for my truck shows 4700 lbs. but that is the 2013 model with 9 more horsepower. My 2007 is the new body style by the way.

I've attached the GMC towing guide for 2007 and it confirms the max tow of 4600 lb. If you were to change the rear ratio to 3.73, the max tow limit increase to 6600 lb. See pg 6...

http://www.gm.ca/media/vehicles/comm...rochure_EN.pdf

Dave

[inspireart]

C10543 - Crew Cab, 5' 8" Short Box
2087 (4600 lbs) 3.23
2WD 2994 (6600 lbs) 3.73

Wow great! My truck was built at the Windsor plant and my daughter lives in Toronto.

My Canadian friends come through again... thanks.

6600 LBS would take the pressure off quite a bit.

Anybody know the process GM uses to reset the vehicle for the new gears? There is some kind computer box that is hooked up to the truck and the speedometer and shift points are reset.

[prof_fate]

You'll probably have to got the dealer and pay the piper for the proper eprom flash - assuming they'll do it. Dealership techs are very leery of changing anything from 'stock'.

Having been a ford guy for 25+ years I know it changes from time to time and model to model what and how they do it. ON my 2001 expy there are two computers - one for the engine and one "GEM" as ford calls it htat is very very VIN specific - the interior lights, key fob, transmission and transfer case and a few other things are all run off this computer.

I know my mother in law with an 03 malibu had her fuel pump replaced and had to go to a dealer to get the computer flashed - don't ask my why/how a fuel pump change required a computer reprogram, but without it she got 15-19mpg and after was back to her normal 25-30mpg.

So many things are integrated anymore than it can be difficult or impossible to change something and not have to change 10 other things - or suffer the consequences.

Does the fuel curve change with the new gears? I'd assume so - the revs the engine will be running will be higher, on average, than before - so what other things might change? Temp settings, warm up time, something else?

What other changes were made to get that extra towing capacity? Trans cooler and gearing - or something else? (Bigger brakes? Shocks? Suspension settings? ABS settings? trans shift points (or trans itself?), ujoints, rear axle? I know many of these things change between a 1500 and 2500 and from having worked in several dealerships it's common to have 'running changes' during the year and from year to year and some are very very subtle and poorly documented.

For example, in early 2000 ford (on triton V8s at least) used a head sensor for engine temp and a coolant sensor for engine temp- in late 2001 only a head sensor and the gage was run off the computer. Small detail unless you are trying to diagnose a hot start issue and even the dealer can't tell you what sensor was in your truck as the change was a 'running change' and wasn't necessarlly a 2000/2001 MY changeover so what a specific truck has can really only be determined by looking at the truck and knowing what you're looking for!

[inspireart]

Have thought about all those issues. Would rather have a smaller trailer than mess up a practically new truck.Thanks, Bruce

[Cajun Po-Boy]

Originally Posted by inspireart

Have thought about all those issues. Would rather have a smaller trailer than mess up a practically new truck.Thanks, Bruce

Great plan...Good Luck!

[thebrakeman]

My sister and BIL bought a Sierra with that 4.8L V8 and 3.23 gearing before they decided to buy a camper. For a pickup, it's great on mileage. When I looked in their manual to help them search, I found that same 4600 (4700?) rating.

fyi - The link from Dave-Monica also shows you have 10,000 lbs GCVWR (combined rating), which would increase to 12,000 lbs with the 3.73 gearing.

I recommend you get the empty truck weighed, and subtract from 10,000 lbs. This will tell you exactly how much YOUR truck can haul (in the truck, plus behind the truck). Subtract the weight of you and the DW. What's left is what's available for the loaded trailer and anything in the truck bed.

Most likely, you will be somewhere around 4500 lbs. Subtract the 3600 lbs empty camper, and you only have 900 lbs available for stuff in the camper and in the truck bed. This is doable, as long as you stay in the mid-west area (that means, relatively flat).

Installing a trans cooler will help protect the trans, but as has been stated, that 3.23 gearing is your limiting factor. Be ready to pull out of OD if there is any sign that it can't find the right gear. If you are able to swap to the 3.73 gearing, you will be in much better shape. It would probably be able to run this trailer in 4th (OD) rather than 3rd, which may be better in the long run gas-wise.

[inspireart]

My long trusted mechanic suggested that I just go with the transmission oil cooler. GM has been zero help on finding out about the EPRON flash.

[thebrakeman]

I think it's fine to try it with just the cooler upgrade. I would recommend you get a ScanGuage so you can monitor trans temp and many other items. I love mine. It plugs directly into the OBD connector under the dash.

Just accept the possibility that you may need to do other work after you go on a trip or 2. You kept this truck in good shape. You don't want to screw your transmission by forcing it to work too hard with that diff.
Keep us informed.

[grayfox]

FYI

First Drive: 2013 Ram HD 2500/3500 - PickupTrucks.com News

[dzg]

Horsepower doesnt matter as much as torque. I tow my 7000 lb salem with a 77F250 that makes a whopping 169hp. But it makes decent torque (325ftlbs) at a nice low 1200 rpm. Low end torque is where its at.

Not to metion highway 3.07 gears.

Usually brakes,wheelbase and suspension play into more then engine power

[inspireart]

Thought I would resurrect this post. Getting closer to retirement and buying a Mini-Lite.
Decided My Sieera would never be a decent tow vehicle. I love it for it's smooth car like ride and great gas mileage. So I bought a second pick-up truck. This one has the factory heavy duty suspension and factory heavy duty towing package with the 3.73 rear end. The quoted towing capacity is 4800 lbs. for my Sierra vs. 8100 lbs. for my new used Silverado. Thanks for all the sugestions the first time around.

[wsteward]

After reading all responses it sounds like what I went through. I had a 94 Silverado 1500 350 and bought a small TT after upgrading from a pop-up. Added a transmission cooler and brake controller but it still did not cut the mustard. On flat ground it was OK but the overpasses on the expressway killed me and gas mileage went into the toilet. So finally bought a 2500 with the towing package and that was that. I was even able to upgrade to a larger TT so I know you did the right thing.. Happy Camping...