Increase My Towing Capacity?

cflgm · February 9, 2011

I posted a topic on Sunday in the Fullsize Truck section and have a follow up that seems more appropriate for here (sorry for the multiple topics).

I have an 09 Silverado Crew Cab with the 4.8L and 3.23 rear end. According to my OM, I can tow 4,700 lbs (max rig total of 10,000 lbs).

I am shopping for an offshore boat and would like to be able to pull up to 5,500 lbs. I checked w/ a couple local GM dealerships on a quote to swap to a 3.73 and they said I need the whole unit which is $3,700 for parts and $400 for labor. REALLY?

Does anyone know if this is true or if I can just swap the gear itself? I assume there would be some reprogramming needed...but that just seemed outrageous.

If a 3.73 is too big, is there an option for a 3.42?

And if a gear swap is not a good option, is there anything else I can do to get another 500 lbs of capacity?

I only have 30K miles on the truck, so I don't want to do anything that will void my warranty.

Thanks everyone!!

Diesail · February 9, 2011

You can swap just the gears, find yourself a driveline shop in your area. The will be able to do it. What I don't know is what sort of programming is involved. But before you go doing all that, what kind of terrain and what sort of distance will you be traveling? If it is fairly flat and distance short I would be inclined to tow it first and see how it does.

Stevens03 · February 9, 2011

Since you have the 4.8, I wouldn't do anything less than 4.10 gears. That will get you the most bang for the buck. If you take your truck to a good offroad shop, they should be able to do a gear sway for around $500 for a 2wd pickup and around $1500 for a 4wd. This would include the gears, master rebuild kit, and labor.

Next would be long tube headers and custom tune. Both will help with some extra grunt. But in my opinion, the 4.10 gear swap will give you all you need. But regardless of what gears you pick, you'll need to have your ECM programmed for the new gears.

music · February 9, 2011

How far are you towing the boat, hills, etc? Payload/handling/braking will be the same, so you're really only talking power and stress on the drive-train. 500 lbs over would just mean pulling out even slower and driving easier. If you plan to tow longer distances or often, a gear swap and reprogram for the gears is the most bang per buck. I haven't had it done, but all $$ figures I've seen have been consistent with what Stephen stated.

I'd get the boat and see how it does before jumping too deep.

Diesail · February 9, 2011

While I will not arque with Steven, His advice is spot on if you are going to do a lot of towing. I do still have to ask about distances and terrain, I used to pull 8k about 5 miles each way to the ramp with an S10, while I sure wouldn't do a 1200 mile tow with it, it did work great to launch and pull the boat about 3 times a year.

So, why void a 100k axle warranty and reduce gas mileage for something you do only 1% of the time?

cflgm · February 9, 2011

I live in south FL (everything's flat and hot) and will be pulling it 10-50 miles (each way) at least 2x per month. Will probably do longer trips (300+ mi) a couple times per year.

I also need to consider my GVW since I'll likely have 4 adults in the truck + cargo (man, this adds up quick).

If I have a local shop swap the gear, will it void my entire powertrain 100k mi warranty? With only 30K on the truck now, that's not something I'm willing to do.

tyhuck · February 9, 2011

I live in south FL (everything's flat and hot) and will be pulling it 10-50 miles (each way) at least 2x per month. Will probably do longer trips (300+ mi) a couple times per year.

I also need to consider my GVW since I'll likely have 4 adults in the truck + cargo (man, this adds up quick).

If I have a local shop swap the gear, will it void my entire powertrain 100k mi warranty? With only 30K on the truck now, that's not something I'm willing to do.

I dont see how the dealer would ever know unless your rear axel is what failed and they opened the diff to investigate. The new parts should be warrantied themselves so if thats the case, just take it to the shop that did the swap, not the dealer.

Diesail · February 9, 2011

If I have a local shop swap the gear, will it void my entire powertrain 100k mi warranty? With only 30K on the truck now, that's not something I'm willing to do.

It should only void the warranty on axle. But if you go to 4.10s and that was not an option then it could be possible for GM to void the entire powertrain warranty. I would talk with the dealer and see what they say.

Diesail · February 9, 2011

I dont see how the dealer would ever know unless your rear axel is what failed and they opened the diff to investigate. The new parts should be warrantied themselves so if thats the case, just take it to the shop that did the swap, not the dealer.

The dealer is going to knoiw because the computer is going to need to be reprogrammed for the gears.

tyhuck · February 9, 2011

I live in south FL (everything's flat and hot) and will be pulling it 10-50 miles (each way) at least 2x per month. Will probably do longer trips (300+ mi) a couple times per year.

I also need to consider my GVW since I'll likely have 4 adults in the truck + cargo (man, this adds up quick).

If I have a local shop swap the gear, will it void my entire powertrain 100k mi warranty? With only 30K on the truck now, that's not something I'm willing to do.

I dont see how the dealer would ever know unless your rear axel is what failed and they opened the diff to investigate. The new parts should be warrantied themselves so if thats the case, just take it to the shop that did the swap, not the dealer.

I can tell you what the dealer is going to do. They are going to pull some hosreshit reason out of their ass as to why the gears would void any and all warranties. Even though, in this instance it makes a little sense that this mod would affect the powertrain somewhat. I guarantee they will make some sort of remark like, "Theres a reason that ratio wasnt offered with that package". They will look for any reason to squirm out of warranty work. I guess they make more money if its coming out of your pocket as opposed to coming from GM. I dont care much for dealerships. Ive found that people at deaperships are totally clueless or crooked, or both (most of the time, not all).

Ive had some bad experiences with dealerships. Can you tell?

riverrat69 · February 9, 2011

I live in south FL (everything's flat and hot) and will be pulling it 10-50 miles (each way) at least 2x per month. Will probably do longer trips (300+ mi) a couple times per year.

I also need to consider my GVW since I'll likely have 4 adults in the truck + cargo (man, this adds up quick).

If I have a local shop swap the gear, will it void my entire powertrain 100k mi warranty? With only 30K on the truck now, that's not something I'm willing to do.

Just changing the rear end ratio is not the only thing you need to consider. Just a few others, tranny cooler, engine oil cooler, tongue weight. Don't forget to add the weight of your trailer and the fuel and other stuff you load the boat with. Going to the local ramp, better hope it's not too steep, is not the same as towing 300 miles in Florida in August. My opinion, is you need a different truck or a smaller boat.

az'03Silverado · February 10, 2011

I posted a topic on Sunday in the Fullsize Truck section and have a follow up that seems more appropriate for here (sorry for the multiple topics).

I have an 09 Silverado Crew Cab with the 4.8L and 3.23 rear end. According to my OM, I can tow 4,700 lbs (max rig total of 10,000 lbs).

I am shopping for an offshore boat and would like to be able to pull up to 5,500 lbs. I checked w/ a couple local GM dealerships on a quote to swap to a 3.73 and they said I need the whole unit which is $3,700 for parts and $400 for labor. REALLY? Does anyone know if this is true or if I can just swap the gear itself? I assume there would be some reprogramming needed...but that just seemed outrageous.

If a 3.73 is too big, is there an option for a 3.42?

And if a gear swap is not a good option, is there anything else I can do to get another 500 lbs of capacity?

I only have 30K miles on the truck, so I don't want to do anything that will void my warranty.

Thanks everyone!!

Isn't the 3.73 gear set only a G80 Locker? If so, this would probably be the reason for having to change the whole unit. Also, since the whole truck is still under warranty, they probably would have to remove an entire "option" and install another entire "option" to keep the warranty intact.

jtramsey · February 10, 2011

I have the same setup.I tow about 5000lbs once a week on a 400 mile round trip.Pulls and stops fine. Of course it will slow you down on hills.I am having a lighter smaller trailer built now just to help my loads.I would not hesitate to pull what you are talking about short distances.Of course I drive under the speed limit and always aware of my surroundings.(Mainly other nuts on the road).

wages999 · February 10, 2011

Isn't the 3.73 gear set only a G80 Locker? If so, this would probably be the reason for having to change the whole unit. Also, since the whole truck is still under warranty, they probably would have to remove an entire "option" and install another entire "option" to keep the warranty intact.

I have 3.73 gears and no G80 locker.