1/2-Ton DD/TV suspension & tires

[Duramax3oh]

New to AS and towing in general... and I know I'm WAAAAYYY overthinking things here but I just like being as well-informed as possible. Former CFP professionally, soon to be CPA, so my attention to detail and need for "planning" drives the wife NUTS.

I have a 2020 Silverado 1500 Z71 3.0L Duramax as my daily driver. I come from a Ford Raptor so I'm not pleased with the OEM Rancho shocks and was planning to upgrade the suspension to King Coilovers (much better shocks, typically for off-road) to get a similar driving feel. This would raise the front end approximately 2" front stock height. I do not have much rake as it is now, the rear sits maybe an inch higher than the front, so I would add a 1" block to the rear to get the truck leveled. On top of that my plan was to go one size larger on the tires from 33"(275/60R20 OEM tires) to 34"(275/65R20 BFGoodrich KO2).

That was my original plan and I was all set to order... but then the wife said let's get an Airstream and who am I to argue? We now have a 23CB International. And I ordered the Equalizer weight distributing hitch. This will still largely be a daily driving vehicle but we're going to tow a decent amount. From Texas to Louisisana. And from Texas to and throughout Colorado area.

With all that said, I'm slightly concerned about how all that will effect towing the AS. (1) Leveling the truck, although the shocks will be 100x better than stock... and (2) going up 1" in tire diameter and into beefier A/T tires. Not quite as concerned along flat land but once we get into Colorado.

You AS'ers have me about convinced I'll be getting a Roadmaster Active Suspension kit to add to this.

Am I completely overthinking this for no reason?
Should I just switch to Bilstein 5100's and get the BFGoodrich KO2's in the 33" size I have now?
Should I not get the KO2's at all?
I think the RAS would help... don't want to run to airbags right out of the gate but should I?

I'd love a perfect driving daily driver and superb towing vehicle all wrapped up in one but know I can't have my cake and eat it too! Just trying to get as best of both worlds as possible.

[ROBERT CROSS]

Disclaimer....I noe nuthing.

Toe with what you have and add what's needed as you need it.
Forget add-on airbags they do nothing to increase payload or improve safety.

Leveling the truck after hitching up is done with the WD hitch. Forget the "blocks"

POI... all add-on's reduce payload.

Bob
🇺🇸

[pteck]

As an avid Airstream enthusiast, off-roader, engineer, and modder, I think you can have your cake and eat it too.

KO2s - while these have been a benchmark tire for a long time, particularly for off-road durability and aggressiveness, the current competitive set has gotten much better. Better balancing the qualities of ride, noise, lateral handing, etc. I think you can do much better all around than the KO2s that have been on the market for awhile. You might find this video informative, from a professional tire tester. In the vain of KO2s, I highly recommend Falken AT3Ws and Toyo AT3s.

https://www.youtube.com/watch?v=cEKwE919YFw

Newer 10-speed transmission have low and broad gearing in spades. With excellent bottom end gearing, while also having solid overdrive gears for freeway. You won't have tractability problems going from a 33" to 34" tire.

Kings as racing coilovers aren't really suited for towing. Their rebuild interval is also not so great as race focused parts. Bilsteins would be good however, to get more damping to help control loads.

I would temper the want to lift too much as that may compromise stability. Mild 1-2" is likely fine however.

If you're biasing the vehicle for off-road performance (with off-road large diameter tires), I would not get the roadmaster active suspension. While they may help towing, they will also greatly compromise articulation. I think you will do fine with dialing in the weight distribution hitch. If you do find yourself wanting more stability or control, air bags are a good way to have the duality of load support with increased spring rate, while allowing adjustability to deflate for articulation off-road.

[JonDNC]

I have KO2s on my F350 and very happy with them. Obviously not extreme off road but good enough. Key in my mind is load rating compromise. You can get the KO2s with a load rating not sure about the others. For towing this matters. Not as much with a 23 but definitely with my 27.

[Duramax3oh]

This is fantastic information above gents, thanks for giving me so much to mull over. As much as I want to "figure it all out right now", it probably is best to take it one step at a time and tow with it is now for a little and just build onto it.

Really appreciate your insights pteck... with not spending hardly any true off road time I wasn't too worried the rebuild side of the Kings but with driving a lot more and towing the AS I was wondering if that might make me have to work on those sooner.

Good to hear your thoughts on tire size too. The biggest reason for the tire size change would be to fill out the wheel wells from the truck sitting higher. And the only reason for it being higher was to have that King suspension. So if I were to go away from that, I'd probably just stick with the stock tire size.

[ChuckFeldt]

Thoughts on lift and tire size. Both will raise the center of gravity. Negatively impacting towing safety. The additional drop shank length will introduce flexibility to the hitch gear. The tire diameter change will effect total at wheel torque/horsepower. Likely reducing acceleration and cruising comfort. I have the 2500 Duramax Z71 and the Rancho’s have been great for towing stability.

[jaybauman]

Originally Posted by ROBERT CROSS

Toe with what you have and add what's needed as you need it.

Your trailer is well-within the performance capabilities of your truck. However, why don't you spend a bit of time towing with stock configuration to see how it behaves, which might help you decide how much you want to change your tires and suspension. This could help reduce future buyer's remorse.

Originally Posted by ROBERT CROSS

POI... all add-on's reduce payload.

This is important to keep in mind. Once you've loaded your stock truck and hooked up the trailer, spend some time at the CAT scales to see how much payload bandwidth you have remaining to spend on vehicle customizations.

[Duramax3oh]

Originally Posted by jaybauman

Your trailer is well-within the performance capabilities of your truck. However, why don't you spend a bit of time towing with stock configuration to see how it behaves, which might help you decide how much you want to change your tires and suspension. This could help reduce future buyer's remorse.




This is important to keep in mind. Once you've loaded your stock truck and hooked up the trailer, spend some time at the CAT scales to see how much payload bandwidth you have remaining to spend on vehicle customizations.

Great points all around. The ol' "it's not what I want to hear but its what i NEED to here."

[Duramax3oh]

So thought I’d come back and say you guys were right. Just picked up the TT and towed it back home just shy of 200 miles. The truck and equalizer wd hitch both performed to perfection. I am just really pleased with how the truck handled. Chalk it up to another example of me getting ahead of myself and overthinking things. Will have 2 long trips coming up the next couple months into the mountains so will stick with what I got and go from there.

For future reference: the Michelin Defender LTX M/S seems to be highly regarded. As much as I want the look of an A/T like the KO2 it’s not what would be best for me. Are the Michelins all they’re hyped up to be?

[Oreg52]

You may want to consider the Michelin Agilis® CrossClimate. Stiffer sidewall adds stability and a higher load rating. It also has a more aggressive tread design than the Defender. Since it is a commercial tire, tread life is shorter.

https://www.michelintruck.com/tires-...E&gclsrc=aw.ds

[Lance M]

Originally Posted by Duramax3oh

Are the Michelins all they’re hyped up to be?

I think they are.

[nvestysly]

Are you certain the OEM shocks are Rancho? I would not recommend the Bilstein 5100's - not that they are a bad shock, I just don't think they'll do much for you. We have a 2018 GMC Sierra 1500 with the max trailering package. Changing to Bilstein 5100's did very little (maybe nothing) to change the ride. Your results may vary, you have a different truck, but I guess I'm saying the OEM shocks on our truck were as good as the Bilstein 5100's.

[rbs]

Originally Posted by Duramax3oh

So thought I’d come back and say you guys were right. Just picked up the TT and towed it back home just shy of 200 miles. The truck and equalizer wd hitch both performed to perfection. I am just really pleased with how the truck handled. Chalk it up to another example of me getting ahead of myself and overthinking things. Will have 2 long trips coming up the next couple months into the mountains so will stick with what I got and go from there.

For future reference: the Michelin Defender LTX M/S seems to be highly regarded. As much as I want the look of an A/T like the KO2 it’s not what would be best for me. Are the Michelins all they’re hyped up to be?

relate our experiences towing a 25' Classic with F150 using PP hitch. With a properly set up hitch we still experienced "porpoising" and determined after research to replace the C rated tires with E rated and remove the factory installed Rancho's and install Bilsteins, fixed the problem. The F150 did a beautiful job, but Cat scales showed that we were right at the GVAR loaded, but not the load that we would need to put into the truck for extended trips. We went with the SuperDuty, strictly for our needs and it has worked for us. Your needs might be different, but just wanted to make you aware of side wall stiffness and how it affected us. Going on a Cat scale would be a wise move.

[GettinAway]

I switched to Bilstien 5100s on my Tundra. Just leveled the truck, didn’t increase the rear. They helped with ride, towing and not towing. I’m switching to 10 plies on the tires. That will help a bit more. I may add airbags, still on the fence with those. I pull a 25’ AS FB, which has quite a bit higher weight than the 23s. I think if I really wanted another few inches of lift, I’d go to a 3/4 ton. But I can’t fit a stock height 3/4 ton in my garage.

[GPurcell]

I love threads like these. So to answer your question - yes to all.

Currently have an f-150 with 315/70r17 ko2's on stock raptor wheels. You should be familiar with that setup from your raptor.

Anyways, with those wheels/tires and a leveling kit with fox shocks, the truck tows great. Now that I have an Airstream as well, I added an add-a-leaf in the rear.

Where you actually have a massive advantage is - diesel and 10 speed. I only have the 6 speed and the 5.0

To compensate for the tires I have regeared to 4.11. Stock gearing as a raptor.

You should have no issues whatsoever with the setup you want to run. I think the only thing you will notice is a decrease in mileage.

[Duramax3oh]

Thanks again everyone for the comments above, they really are helpful.

After a 2400 mile trip I can say the stock set up still works well. Overall I'm pleased but know I do want to get a stronger LT tire and do want to upgrade the suspension. I've got a 700 mile trip next week and then we're packing up for a much longer trip probably in the 4k range. Won't be replacing anything before then so I'll still have plenty of miles to debate myself and put wear on these stock tires.

With that said I'm somewhat concerned about the rear-end squat, what's normal/acceptable vs. where I need to take corrective measures.

Normal stance my truck sits with the rear about 1 1/4" higher than the front (measurement from ground to lip of wheel well). When trailer (5800 lbs) is hooked up with WD hitch, the front end raises about 1/2" while the rear sags about 1 1/2" for a net decrease (if you will) of 2". So the front-end sits up about 1" higher than the rear. It doesn't look bad and still seems to handle well but should I be attempting for the truck to sit more level?

Went though CAT scales:
Truck Only: Front axle 3320 lb, drive axle 2420 lb
Truck + Trailer: Front axle 3260, drive axle 3200, trailer axle 5020 (trailer added 5740 lbs)
Fully loaded for trip (wife,dogs,gear): Front axle 3440, drive axle 3460, trailer axle 5080.

Should I adjust the hitch to attempt to move more weight to the front axle?

[Daquenzer]

Your distribution is fine. I wouldn’t mess with the WD hitch. In fact if you only take 60lbs off the front axle that is great.

If you are looking to reduce squat I would go with Roadmaster Suspension System Heavy Duty. I have Roadmaster on my present F150 and it works great. I have absolutely no squat on my truck when I adjust the WD hitch. And I have a propride hitch as well. So I have about 1200lbs on my hitch receiver. Also Roadmaster completely eliminates the porpoising.

Also the Roadmaster helps with the handling of the pickup all around even when not towing.