Towing Suspension Suggestions

Finally got around to hooking up the TT & towing it around. When attaching the load stab bars, I raised the rear half of what I normally do. As you can see from the pics, the RAS-HD did the rest. Zero sag. The ride was noticeably better w/o being stiff. Headed out for a multi-day trip next week. First impressions, tho, are excellent!

 

@Chad D. How did your truck do towing with the Deaver springs? I also have u748 and I'm towing a small trailer with 400 pound hitch weight, 3100 pound dry weight and adding a 380 pound quad to the bed. Also have WDH I'm going to use. I have sumosprings in box, but I wonder if they're even necessary.

 

I did a lot of research on RAS, and have purchased the HD version, not yet installed. I looked all over, even other 1/2 ton and HD truck forums. What I learned was that it does raise the rear about an inch. It is not meant for lift, more of a side effect of the additional support as tundra leafs and pretty soft. So, little to no lift, about an inch potentially but much of that can depend on the condition of your stock leaf springs.

 

I run a Fastway e2 with roughtly 650-800lbs of tongue weight. Stock rear suspension setup. It's an 08 w/148k miles. Just replaced shocks with new factory take of Bilsteins but the leaf pack is original and seems fairly "worn out". Also have LT E rated tires that when towing I set the rears to 60psi. Properly adjusted the WDH, new shocks, and stiffer rear tires took out almost all bounce. I'm looking to add air bags w/cradles set to a lower PSI to help support the suspension when towing and take the remaining bounce out but while it would be nice...it does not seem 100% needed. Not sure if I will get to it by this next camping season or not, especially since the trailer needs bearings repacked and possibly replaced, and the tires x4 need to be replaced as well. I may also add a rubber dampened center equalizer while I'm at it, but we'll see. A few things to fix / finish up on the camper remodel as well so air bags may have to wait. There's only so much extra cash to go around!

 

@frichco228 Thanks for the additional info! I too have been doing lots of research on forums and reading RAS reviews, and have noticed many saying 1-1.5in higher in rear after install. My Tundra has 71k miles, and maybe around 12k miles towing our TT. The leaf springs do seem to have a flat spot where they make contact with the axle/plate...not sure if this is normal? I have LT load D tires (General Grabber ATX), black Sumo Springs, stock (black) shocks and Equal-i-zer WDH. If the rear raises close to 1in or more with RAS while unloaded, I will install Bilstein 5100's or Eibach Pro shocks all around and set the fronts at either .875 or 1.5 (Bilstein) or 1.2in (Eibach). Trying to achieve less squat and less porpoising when towing TT. I've already made some adjustments to the WDH and am hoping the RAS and possibly new shocks will resolve these issues.

 

I have done a lot of research as well, found it raises .25 to about an inch. I have purchased RAS, not yet installed. Also purchased Eibach Pro Truck 2.0 suspension, not yet installed. Expect about 2inch raise up front, maybe an inch in the rear which will be perfect for my truck.

 

Everything about it is better with the Deavers. Obviously, I had to reestablish the WDH settings after the suspension upgrades. Not just for the new height, but also due to the new springs. I do still have some air in the bags, but not as much as I used to use. Try it without the Sumos and put them in if it's too squishy. I'm sure you will like the setup once it's dialed in!

BTW, my trailer is much heavier. Well over 6,000# and a little over 10% tongue weight. Towing is solid and it always feels in control.

 

Has anyone who upgraded shocks and and lifted notice a huge change in WDH setup?

I had horrible porpoising with the factory black shocks and the hitch dialed in via scales. Height measurements were fairly accurate with recommended install as well. After adding 5100s set at 1.83 and a CB shims, the front actually needs to drop by almost 3/4" to get the WDH dialed in based on the scales.

Just wanted to share this for anyone who might be following the height measurement setup process, post lift.

Now I need to go look at the RAS and compare it to the bags I have installed. Remembering to keep the bags at 5psi in new england is challenging during transition seasons..

 

I had Air Lift airbags put in this last summer, they are awesome! I usually tow a 6,700 lb dry weight 28’ Jayco travel trailer around. Between the airbags and load distribution hitch I can pull a loaded trailer with no sag. It made the truck handle a lot better too

I had them install a wireless 1 air compressor with the bags and it’s never let me down.

 

What WDH are you using? The friction bar type offers some damping since that's how it controls sway. I'm using a Fastway E2 8,000 with a close to 6,000# trailer with a stock 21 ST5 bumping against GVWR and have only found one long bridge in Louisiana with the expansion joints placed at just the right distance to coincide with the rig harmonics. I slowed 5 MPH and the bouncing went away.
I can see where a chain type WDH could act as an undampened spring and allow repeated bouncing to occur.

I would highy recommend setting up your own WDH according the the manual and not trusting a dealer. When setting mine up I loaded my truck as it would be for towing and had a friend, my wife and dog stay in the truck while adjusting the hitch. Another trick is if your hitch uses washers for spacers, make a trip to the bulk washer bin and pick out a bunch of washers in different thicknesses. On mine 5 included washers wasn't enough but 6 was too much. finding three slightly thinner washers to replace three of the include ones brought the adjustment right where I wanted it.

 

Has anyone ever looked into using a Hensley Hitch?. I use this on my TT #6500, and it distributes the weight perfectly and handles incredibly. I have a stock 2020 DC Sport

 

I don't have enough payload to use a Hensley. It's way too heavy. It also looks difficult to align when hitching and unhitching but probably just takes practice.

 

Finally had time to install RAS HD on my 2016 CrewMax 4WD.

Install went smooth and took close to 2hrs total. I used a quarter instead of the black/white shims provided in the kit to set the spring tension. The quarter is slightly thinner than the black shim which is about twice as thick as the white one.

I measured the rear height from ground to fender before and after install. Immediately after install, I was about 1.5in higher. I figured the truck/spring needed to settle some, so I went for a short drive (around 15 miles) on some rough back roads, then to fill with gas since I was at 1/8 tank. The ride seems slightly better with RAS (without load). Truck seemed to soak some of the small bumps better than before.

After the short drive and now with a full tank of gas (38gal), the rear of truck is sitting 1in higher than before install. I'll be ordering either Bilstein 5100's or Eibach Pro shocks this week, to get the frontend a little higher, not really liking the overall look of the truck right now.

I should be picking up my 7k lb TT from dealer later this week. I'll give an update and post a pic afterwards with it loaded up.

 

Thanks, bud!

I'm all dialed in now and it tows like a dream. To answer your question, though, I have the Recurve R3 with 800lb bars (1k were a bit too stiff). I'm within 20lbs of original front axle weight after a few trips to the scales.

Wanted to share my experience for those mentioning porpoising and those considering lifts to offset increased rake with the RAS. Measuring tape will get you close, but scales are a must to dial it all in, and in my experience, the difference between the two methods was much more noticeable post lift.

 

If you’re “distributing” the trailer tongue weight off the hitch, wouldn’t your front axle have more weight on it when appropriately adjusted? I get that you’ve pushed some of the weight back to the front, but that isn’t putting the tongue weight up there.

I set mine only by measurements, as I don’t have a scale nearby. Now I’m curious…

 

I hear you, and I was equally as surprised, but the scales don't lie. Why is beyond me, but figured I'd share since it took me half my camping season to finally get frustrated enough to ditch the tape and commit to the scale work.

Pre-lift I was within 60lbs. I was surprised to realize post lift I was still 140-160 light on the nose. Without distribution was about 300 light, IIRC. Now it's dialed in within about 20 and the towing experience reflects it.

To get this back on track, I'll recap my inputs here: porpoising sucks, upgrades help, be cautious of different distribution results afterwards, scales are your friends, you'll know when it it is right and don't settle for less because towing is already dangerous enough.

To help get this thread back on track, after looking at the RAS, I'm wishing I had gone this route over bags. I suspect they'd fair better up in New England and appear to require less maintenance. I'm debating going with the HDs since almost nothing has a <600lb in-use tongue weight these days.