Hi,In great need of help.We have bought 2 years ago a 2007 silverado 1500 crew cab standard box 4.8l V8 with rear axle ratio of 3.23. Last year my parents gave us their dutchmen four winds trailer which has a unloaded weight of 4234 pounds ( says in the manual that tongue is included in this number)it is also equiped with a weight distributing hitch and sway bars. Having said that, this is our situation. We attempted to go on a fishing trip in LaVerendrye parc last year which is equivalent to crossing the adirondacks in regards of hills. My hubby is a mechanic but has no experience in towing travel trailers. I was towing the boat with my van and he was towing the trailer with the truck. After a few stops he said that he was about to let the trailer on the side of the road, that is how bad he found the truck to struggle up hills. With the gas pedal almost on the floor and in 3rd the truck was still loosing speed in those steep hillsand the engine was running pretty high. My father who is accostomed to towing said that it was pretty normal going up steep hills to drive at 35-40mph. My hubby says the problem would be resolved by changing the axle to 3.73. My question is since he is not experienced in towing is he just scared for nothing and all above details are normal?here are some specs:The trucks max loaded trailer weight rating: 4500 poundsThe trucks real weight with all occupants ready to travel: 5600 poundstrucks gcwr: 10000 lbtrucks gvwr: 6900 lbtrailer loaded weight: 4500lbtrailer tongue weight 650lbNote that we would travel maximum 2 times a year making 2200 miles round trip from montreal to myrtle beach going thru the AdirondacksHope someone can help us

I disagree with your hubby. The biggest problem is lack of cubic inches in the motor. It is simply too small. You need to either get more truck or waaayyy less trailer. Your choice.

If the truck has the 4-speed 4L60E / M30 transmission my Envoy was running 4,000 RPM in 2nd gear going up some hills.You're max'd out right now. The money you'd spend on a gear change would be better spent on a heavier truck.

I have a 2006 GMC 1/2 Ton Company truck that I have had since it was new.It has the 4.8L Engine and currently has a little over 250,000 miles on it. It has been a great problem free truck but it has very limited load / towing capacity due to the small displacement engine.With any sizable load or weight it will struggle on even the smallest hills.I would never attempt to pull a Travel Trailer of any size with it !!!

I agree with DH. Unless you just want a larger truck, your trailer is not THAT heavy and the pulls in your area, IMHO, are not that tough. There is a lot of difference in 323 & 373 gearing. Either way, to some extent, you will just have to get used to a little struggling with a gas engine.

Honestly. Going from 3.23 gears to 3.73 gears would be like night, and day. 3.23 gears in ANY truck will kill the towing capacity. While the 3.73 won't make the little V8 a towing monster. It will greatly improve the towing experiance. But be ready for higher RPM. As the 3.73 is a much lower gear. It will cause the engine to run at a higher RPM, a RPM where in fact the little engine will make most of it's power. A gear change, around $1000.00 is way cheaper than a new truck. The only reason your truck has the 3.23 gear, is to help GM pass the federal fuel requirements. They are useless for anything else. As I say. The 3.73 won't make it a monster. But it will get you there, and yes, It will rev up as it changes gears down, going up hills. that is normal. I'd try it first. You DH may even be able to do it him self. Saving you everything but the parts. Prolly saving around 600 bucks. Again waaaaay cheaper than a new truck.BTW. that is how the manufacturers change the towing capacity. they change rear gears

rear axle ratio change better towing capacity

donn0128
Explorer II
Apr 28, 2013
I disagree with your hubby. The biggest problem is lack of cubic inches in the motor. It is simply too small. You need to either get more truck or waaayyy less trailer. Your choice.
mbopp
Explorer
Apr 28, 2013
If the truck has the 4-speed 4L60E / M30 transmission my Envoy was running 4,000 RPM in 2nd gear going up some hills.
You're max'd out right now. The money you'd spend on a gear change would be better spent on a heavier truck.
Rob_Fla
Explorer
Apr 28, 2013
I have a 2006 GMC 1/2 Ton Company truck that I have had since it was new.

It has the 4.8L Engine and currently has a little over 250,000 miles on it.

It has been a great problem free truck but it has very limited load / towing capacity due to the small displacement engine.

With any sizable load or weight it will struggle on even the smallest hills.

I would never attempt to pull a Travel Trailer of any size with it !!!
campigloo
Explorer
Apr 28, 2013
I agree with DH. Unless you just want a larger truck, your trailer is not THAT heavy and the pulls in your area, IMHO, are not that tough. There is a lot of difference in 323 & 373 gearing. Either way, to some extent, you will just have to get used to a little struggling with a gas engine.
Terryallan
Explorer II
Apr 28, 2013
Honestly. Going from 3.23 gears to 3.73 gears would be like night, and day. 3.23 gears in ANY truck will kill the towing capacity. While the 3.73 won't make the little V8 a towing monster. It will greatly improve the towing experiance. But be ready for higher RPM. As the 3.73 is a much lower gear. It will cause the engine to run at a higher RPM, a RPM where in fact the little engine will make most of it's power.

A gear change, around $1000.00 is way cheaper than a new truck. The only reason your truck has the 3.23 gear, is to help GM pass the federal fuel requirements. They are useless for anything else. As I say. The 3.73 won't make it a monster. But it will get you there, and yes, It will rev up as it changes gears down, going up hills. that is normal. I'd try it first. You DH may even be able to do it him self. Saving you everything but the parts. Prolly saving around 600 bucks. Again waaaaay cheaper than a new truck.

BTW. that is how the manufacturers change the towing capacity. they change rear gears
2500_Grunt
Explorer
Apr 28, 2013
You said "the engine was running pretty high". What is the red line or max RPM of the truck and what was the engine running at when he said that it was struggling? If it red lines at 8000 RPM'S and he was only at 4000 RPM's and going 30-35 RPM's with the pedal to the floor then a gear change will help unless he can manually pull it down a gear to get RPM'S up higher without losing speed. Towing isn't racing so don't expect to maintain normal speed when towing especially with the tow vehicle you have.
I_am_still_wayn
Explorer
Apr 28, 2013
Changing from 3.23 to 3.73 would provide a 15% gearing advantage. While significant, it will not increase POWER and that little engine just doesn't have the power. You can accomplish the same thing as increasing the gear ratio by lowering the gear you are using in the transmission. You will go slower but have the same RPM's as with the 3.73 axle ratio.
ktosv
Explorer
Apr 28, 2013
Our 2005 1/2 ton Suburban with the 5.3L and 3.42 axle did a great job towing a 5000 GVWR hybrid with 6 of us. I would have to think that a 4.8L and 3.73 would be comparable.

Is your truck 2wd or 4wd? If your husband is a mechanic, can he do the gear swap? If so, it would essentially only be parts to do the swap.

What gear was he towing in? Tow/Haul on or off? What all do you use the truck for? Is a 3.73 or 4.10 axle going to render the truck useless 90% of the time?
monmil
Explorer
Apr 28, 2013
Thanks for the replies. If we could find a mechanic that would do it for 1000$ I would do it in a blink of an eye but hubby wants to do it himself cause it is very unlikely he says to get it done for 1000$ in Canada. I am just scared about the computer and transmission tuning I have heard about when attempting to change gears. Some even say it has to be factory made and cannot be changed :(
monmil
Explorer
Apr 28, 2013
To the questions asked by 2500grunt and ktosv:
The truck is an automatic transmission 2WD and he was at around 4500-5000rpm going 45-50mph at most uphill ( no problems going straight or downhill :) ). He said he had put it in 3rd speed. The tow-haul button was on.
He mainly uses it to transport drywall and tools in the box and tow a 1000lb trailer every other day. His concern with changing the gears is the fuel consumption when not towing the trailer which would only be 2 times a year. He also says buying another truck just for 2 camping trips is not worth the change. He is actually leaning towards giving back the trailer and renting hotel rooms :( I am very disapointed as I am a camping fanatic ( Did camping every single year up till I was 20 years old and loved it)

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