Mods needed to max potential for tow

medik13 · February 9, 2019

Figured I’d come back and post this here. Looking for advice. I have a nnbs with 5.3, 4x2, 6 spd., 3.42, HD cooling package, bb tune, 33” tires and 5” lift. It has towed my 22’ boat with no problem. I am looking to add a 28ft TT (6.5-7.5K) to my toy list.

I want to upgrade brakes (suggestions needed), gears to 4.10 with tru trac and mag-hytec cover, upgrade factory cooler to tru cool 40K transmission cooler, and firestone or air-lift bags for the leafs.

How does this sound? Any other suggestions/ input?

intheburbs · February 9, 2019

Bottom line is you have a weak semifloater rear axle, with additional stresses put on it because of the lift and larger tires. No mods you make, short of replacing it with something stouter, change the fact that you have a 3950 RAWR and a 1500 lb-ish payload.

Towing a 7,000-lb trailer with a lifted half-ton truck with oversized tires will cause stuff to break.

I had a half-ton Suburban, factory suspension, no lift, and I broke the rear axle twice towing trailers around 7,000 lbs.

redwngr · February 9, 2019

Get a 2500, would be the best suggestion.

Especially if you are concerned about braking already.

Massive brakes.

Massive frame (by comparison to a 1500).

Already 4.10's , if you get the gasser. Unnecessary with the dmax.

FWIW, 2011 was the last chassis update for the HD's.

Significant improvements compared to 2010 and earlier HD's.

2020 will be the the first HD chassis update since then, despite the body changes.

medik13 · February 9, 2019

I wouldn’t be opposed to beefing up or new rear axle. It’s much cheaper than a new truck. What would you recommend in terms of new axle?

Not really worried about braking, it’s just time to replace brakes and I know there are some some good aftermarket upgrades out there. I went to the dealer and had all the related codes deciphered. HD cooling and max trailering package with the 3.42 gears. The GCWR is 15K and the max trailer weight is 9600 according to the manual. Dealer of course recommended I go 30% less to be safe. I am well within that range seeing as the trailer I have selected has a 5.3k dry weight and a max GVWR of 7.5k with a 671 hitch weight. I thought this vehicle would be more than adequate.

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intheburbs · February 9, 2019

20 minutes ago, medik13 said:

I wouldn’t be opposed to beefing up or new rear axle. It’s much cheaper than a new truck. What would you recommend in terms of new axle?

Some kind of full floater. My 2500 Suburban has the 10.5" free floater. American Axle rates it to 8600 lbs. In my application, the tires are the limiting factor, so GM rates it to "only" 5500 lbs.

If your truck was stock, you'd probably be ok. But the lift and larger tires will substantially increase mechanical stresses when towing. Bearings see more load, brakes have to work harder and get hotter faster, larger tires lower your effective axle ratio, transmission sees higher torque loads, etc.

Also, keep in mind that a large drop trailer hitch, like an 8" or 10" drop, reduces the weight carrying capacity of your receiver, because you're applying more torque to it. A lifted half-ton is just not the greatest choice to pull heavy trailers.

medik13 · February 9, 2019

Yes, I understand what you are saying but... The truck is only 3” higher than stock in the rear. The drop hitch is a 4” drop hitch and it is only adjusted to the second lower position. The tires are 1.3” bigger than stock. When I regear to 4.10’s the final gear ratio will be equivalent to a 3.73. I didn’t see the difference as being huge and that’s why upgrading the transmission cooler, gears, and brakes made sense... but maybe you are onto something.

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medik13 · February 9, 2019

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Snoringbear · February 9, 2019

If towing a 6.5 ~ 7,5K lb TT you will need a weight distribution hitch. And, being your truck is lifted I suggest one with sway bars as well.

Btw, I agree with the dude who suggested a 2500. Or, a 1500 with Max Tow package. And, forget about the lift business ?

medik13 · February 10, 2019

Yes, I had planned on towing it with a WD hitch and drop shank. I just posted the picture of the hitch to show height illustration and that the truck doesn’t have a crazy lift on it.

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greatmizzou · February 10, 2019

Best thing you can do is drop the lift and get factory sized tires. If you do that AND up the gear ratio, you would see a noticeable improvement in towing. I know it’s not sexy but when it comes to towing Travel trailers are a totally different beast., they will take you for a ride for sure.

IMO, I think it’s pointless adding anything to a half ton truck other then LT tires, good shocks, a premium WD hitch, good brakes, and a transmission cooler w/ temp sensor.

Everything else is is wasted money you could put into a HD truck.

swathdiver · February 10, 2019

I think Medik's truck has a 9.5" semi-floater. Not as stout as the 10.5" but better than the usual 8.6". You got 10 bolts on the differential cover or 14 Medik13?

What's that shank mount rated for in the lowest position (or where it is now) with a 2-5/16" ball?

medik13 · February 10, 2019

No. I don’t have the max trailering package. I wish I did. I have the 10 bolt rear, 8.5.

The shank is rated for 15K trailer weight and 1.5K tongue weight. It exceeds the rating of the hitch hookup I have. Either way, actual tongue weight is much less @ 670.

I’d hate to lower it back to stock, but if I have to then I guess I will have to. However, I think I am going to look at the 2019 Silverado 6.2. or an older F250.

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Snoringbear · February 10, 2019

If I were in your shoes I think I would take greatmizzou’s advice. Then, wait till the end of year for 2019’s to drop in price and get a deal on 6.2/10 spd. Or, wait for the 2020 2500 which will offer a 6.7L gasser. However, you may decide what you’ve got works ok, especially if you only tow every now and then. Lots of choices, as most things it comes down to ?...