My Tundra mods for stable towing

I used to have a 2008 long bed, now have a 2021 Crewmax. The CM is an entirely different animal, very roomy inside, tiny turn radius compared to the DCLB. In terms of length my old truck was similar to the HD trucks and also handled very well. Wanted to achieve something close with my new ride. We have an Airstream-28 which is 25ft box size, just under 6000 lbs dry, 850lb tongue weight, 7600 fully loaded (which it never is.) My new truck has 20" TSS factory wheels, the old one had 18" steel rims.

Goals:
- Preserve 'daily' ride quality as far as possible since I only tow about once every 1-2 months (6k miles per year)
- Achieve a firm stable towing experience at all speeds up to 75MPH
- Preserve the factory rake of +2 in the rear
- Maintain low center of gravity, ie. minimal lift

Blue Ox WDH
- Pulled this from my old truck, it's an excellent hitch!
- Relatively affordable compared to other similar hitches
- One of the lighter hitches - important since this adds to tongue weight
- May select different load bars, I picked 1500lb although many go with 1000lb. I figure I'll have around 1k lbs weight to spread around and wanted margin when going over big highway dips at speed.
- With heavier bars less preload is necessary, either one will end up applying the same pressure to the truck/trailer combo when set up correctly
- Very quiet, no squeaking or clanking
- Achieves sway control via an offset cam angle on the bars, no need for extra brakes or friction bars
- Without a doubt a WDH is the most important accessory when towing a heavy trailer.

E Rated Tires
- I had Michelin LTX MS2 on my old truck, it's an excellent E rated freeway tire!
- Now selected Cooper AT3 LTX in size 275/60/R20 for my CM
- It's very quiet, on par with the Michelins
- Excellent snow traction, expect rain and dry performance to be good as well
- Could air down to 42psi (to match door jamb pressure on stock tires) but will run 70psi for towing
- IMO tires are the biggest enhancement to towing stability after a WDH Hitch

Bilstein 5100 shocks
- My SR5 came with the base model 'black' no-name shocks. I had upgraded my old truck with the 4600 series and wanted something similar.
- The Bilstein 5100 set was available for the same price, about $90/corner
- Set the front shocks on the lowest perch, which supposedly gives about 0.75" lift. (The other settings provide considerably more...)
- The ride quality is possibly stiffer than stock but difficult to gauge since tires make a much bigger difference
- If I had a TRD 4x4 or Sport I would have left the shocks alone...

Coachbuilder +1 Shackles
- My previous truck had these, had initially purchased them to mitigate bed bounce. I liked the ride.
- Picked the +1 model since it provides a 0.65" lift which would match my Bilstein 5100 bottom setting on the front
- This preserves the factory rake perfectly, a +2 difference in the rear

Sumo Springs
- Wanted a 'helper spring' to assist the flaccid stock leaf springs
- Considered an Add-a-leaf but didn't want to affect my daily ride quality
- Decided that airbags were too much work and would require adjustment when towing
- First bought the 1500 pound Sumo but they are very, very hard! Did not install.
- Dropped down to the 1000lb model, seems more than sufficient
- After install these had about 0.75-1.0" clearance to the frame, likely due to the increased clearance provided by my front shocks and the CB shackles
- Been driving on these for a few weeks, they have settled to an "index finger width" clearance on both sides
- During unloaded operation they don't touch the frame, except presumably on big humps at high speed. I don't notice them.
- When the trailer is connected, the frame rests on the Sumos with mild compression.
EDIT: After driving with the Sumos with a full load, decided to cut off the top 'donut', otherwise they interfere with the driving too much. The axle, springs and shocks are not able to articulate enough with the full length Sumo spring. I can't recommend.

TRD Rear Sway Bar
- Never ran this before but wow, it makes a difference!
- Truck feels very planted on corners
- Together with the E rated tires, the sway bar makes my truck feel like it's on rails

Very happy with my setup!

 

Thanks BD. Getting ready to RV tow with my new 2021 TRD CM and this is a very good and timely overview. Our intended TT will be smaller and lighter, but the same principles will apply. Appreciate you taking the time to detail.

 

Thanks for sharing your info.

 

Nicely done!

 

Nice setup, and good info.

I love Airstreams!

maybe someday.

SPP

 

Thanks everyone!

Still to install:
- Husky weighted mud flaps (otherwise I get tons of splatter on the trailer with the stock flaps)
- Transmission cooler, it is on order, will have it installed soon

Order links, install videos:
https://www.tundras.com/threads/tundra-transmission-cooler-kit.60550/

 

Lot of good info here. Seems you have a good handle on this. If the time comes and you find yourself wanting to replace those 5100's. Falcon has a rear shock with 3 adjustable setting for unloaded, light load, or towing. Supposedly this gives you a more comfortable ride when you don't have the trailer attached but allows you to stiffen rear when towing to keep everything planted. Just food for thought for future, if you find you need it. If your set up works, don't fix what ain't broke lol

https://www.tundras.com/threads/falcon-shocks-are-coming.34355/

https://www.tundras.com/threads/got-the-falcon-suspension-today.73085/#post-2122775

 

Damn you!

My wife's already asking "When are all the upgrades going to stop!" Every time I look at that truck it's another $1000

The audio system is also in need of complete overhaul. Difficult to imagine coming up with such a poor setup in this day and age when components are dirt cheap to manufacture. It sounds worse than any $50 bluetooth speaker, yes it's that bad.

 

Great write-up!

 

Nice write up buddy good looking set up

 

pretty sure they sell a set of flaps that mounts to the hitch to protect the pretty silver aluminum you tow.. then you could leave the stock flaps alone..just an idea that airstream is very nice

 

Interesting idea! Like this:

$390 Rock Tamers 00108 - 2" Official Mudflap System - 2" Hitch Receiver, Check Measurements - Removeable and Adjustable Mud Flaps for Trucks - 1 System

https://www.amazon.com/dp/B006M9VIR..._wg=sVulf&ref_=sbx_be_s_sparkle_td_asin_0_img

But likely I'll still just run the Huskies since I'm limited on garage space. Between trips I'd need to store those hitch flaps somewhere.

 

Very nice write up and your truck looks great. I have a 2012 DC TRD and am currently running Toyo AT2 P275 60 20's which are only 4 ply and pull a 22' travel trailer (4800 unloaded/6K loaded)with about 750+ on the ball. We do have a Equilizer brand hitch which is wonderful and helps prevent sway but the truck is a little squishy in the wind when towing and looking to remedy that with LT tires but as you probably found out, there is not a lot of LT options in the 275 60 20 arena. Those Coopers look great and have heard good things about them. Do they ride pretty well when loaded and unloaded or are they pretty harsh?

 

Because I keep them around 50psi when not loaded they're a little harsh. Haven't tried at 40psi, this should be close to the door jamb setting for the stock P-rated tires. At 70psi they're certainly harsh if I'm not towing. When towing, the harder the better, truck stays very planted with all that extra weight.

 

Sounds good. Yes keeping the pressure down in the lower 40's should help with ride I would imagine. Also did you notice any less towing performance with this E rated heavier tire.

 

I've always towed with 33" E rated tires, IME performance is fine. On flat ground I've even achieved 12MPG for long stretches, 10MPG is normal however. I run in 'D' mode most of the time, seldom Tow/Haul. In the mountains I'm in 'S' mode and just shift manually.

The increased stiffness of the E tires is such a huge benefit that it totally overcomes any perceived loss in performance. Going from 32" to 33" is pretty minimal in speedo difference, I'd expect towing loss to also be very small

 

I also run Sumo springs, depending on your needs you may want to follow in my path and buy a second set then cut them down to bump stop height. That leaves you the option to simply screw on bump stops when you need factory like axle articulation. Works well for my needs to have a heavy duty hauler with yellow Sumos when needed and swap in minutes to off road abilities.

 

That's a good idea! But it's doubtful I'll ever seek out anything beyond a gravel road.

 

Thanks for the info, I think the 33" is the perfect size on a, little less than leveled, Tundra (Bilstein 5100's on middle setting) and have run a P275 60 20 on my tundra and older F150 and they really ride nice, just never run a 10 ply in that size so was a little skeptical of a harsh ride since this is a family traveling rig. But since we tow 6K, I think I will have to make a move out of the P's to gain a little more sidewall stiffness and for safety reasons. That's great mileage while towing and I usually get between 9-10 and always leave in 5th gear in tow/haul mode at about 60-65 on I90 and it doesn't gear hunt too much either. Where we really notice power loss is when we are towing to the Oregon coast down the Columbia gorge pushing a 25 mph head wind, then I really want a Cummins.

 

I've heard great things about this WDH as well and am planning on purchasing one. Just curious, where did you get one for $300?! Everywhere I've looked has it for $600+.

 

I don't remember. And since I can't currently find any for that price either, I'll remove it from my original post in this thread.

 

Oh, I wasn't saying you didn't get one for that price or anything, I was just hoping you could tell me where so I could get one!

 

I love the write ups. I also tow a heavy camper. A lot of guys tell me it’s too much trailer for my truck. I have a 17 TRD Pro double cab. I tow a 34’ fifth wheel. Dry weight 8,200, hitch weight 1,200. I have the yellow sumo springs, Power Stop drilled/slotted high carbon rotors, carbon fiber/ceramic brake pads. I’m running Toyo Open Country AT3 in 295/70/18. I also have a Bully Dog GTX tuner with a tow tune installed. It allows me to monitor my trans temp. I’ve towed this camper from NH down to GA, then across to San Diego, up to Mt. Ranier in WA, then back to NH, and all kinds of places zig zagged in between. In July and august. The trip took us almost 6 weeks, it was over 10,000 miles. The only issues I had was driving up the Rockies in AZ. Mind you, it was 104* outside. My trans temp got up to around 230*. I slowed down to around 35mph and just tucked in behind some semis and rode with them up the hills. I stopped immediately in Tucson at a dealership and got a trans flush. I had no issues going back across the Rockies up in Montana and Wyoming just a couple weeks later on my way back east. One thing I learned is, if the stuff in the camper isn’t evenly distributed, the rig handles like sh**. I’ve had to pull over at a rest stop and move stuff from the back to the front of the camper, or vice versa. Future upgrades coming very soon include a TRD supercharger, external trans cooler and possibly an engine oil cooler. I’m also looking into upgrading the valve body of the trans and having a custom tune done for the trans as well.

 

You on stock gears?

 

Yes. Stock gears. And I know I should have left the stock tires size alone. But in this case the horse came before the cart. I put the bigger tires on two weeks after I bought the truck. I didn’t get the camper for a year after that

 

Went to the CAT scale today. The drive there felt rather "rubbery" to say the least! (Very windy day)

Ended up doing the following changes:
- Started with 70PSI on tires, dropped to 60PSI to increase contact patch (per pressure charts even 45psi should suffice)
- Cut the top donut off each Sumospring (about an inch shorter.) That way they are not in constant contact, even when towing there's a quarter inch gap to the frame. Can't really recommend them at this point, IMO I'd rather stick with the stock bump stops.

Data:
- Full tank of gas, 38gal
- Full tank of fresh water in trailer, filled for about 3min after 100% was displayed, it's filled to the brim! All usual stuff in trailer as well: Bedding, drinking water, pots & pans, kitchen stuff, knick knacks, paper towels, tool kit, compressor, emergency supplies... only thing missing are a few clothes and some food.
- Combination weight = 13440
- Truck + hitch weight = 6260
- Therefore trailer weight = 13440 - 6260 = 7180
- Trailer axle weight = 6220
- Trailer weight imposed upon truck = 7180 - 6220 = 960
- Gross vehicle weight = 3420 + 3800 = 7220

The bad:
- Right at GVWR of 7200!
- Better pack my firewood in the trailer... and maybe leave my wife at home

The good:
- Not exceeding max combination weight (15400)
- Not exceeding axle limits (4000, 4150)
- The truck burns gas at about 36lbs/hr, LOL
- We don't normally travel with a full tank of water in the trailer, only about 25% full. That should cut about 245 lbs of the load.
- The WDH seems to be doing the job, I have restored the original front axle load

Without the trailer:
(WDH hanging off the back)


With the trailer and WDH fully connected:

 

Wow I have the same truck and same camper! What series is that?

 

2019 Flying cloud (ie. FC28 RBT)

 

Sweet, 27GT here, full Victron / lithium build.