Horrible Handling on Washboard

Yep. Weight in the bed smooths things out considerably. Sandbags in the winter for me, then it's often loaded with stuff in the summer. Good point about 20" wheels here also. Wheel/suspension upgrade may help but at a the end of the day a truck in RWD that is light in the back will always have the washboard issue.

OP, since you live on dirt roads you probably know this... Avoid what you can by picking the right line: aim to drive where others don't (wrong side of the road, edge of the road, or whatever). Also use your 4wd on washboard roads going uphill. It smooths things out (and you are supposed to exercise your 4wd anyway).

 

Your truck had the TRD OR package, and it still wasn't up to the task? Wow.

So, the Toyota engineers missed the off road mark completely with the Gen 3, despite their marketing and advertising efforts. Sad.

 

Thanks. Yes, I know weight in the bed would help. I routinely haul bails of hay for our horses, and that extra weight does help. I'm just trying to avoid loading and unloading heavy sandbags all the time.

And yes, I've lived in the boonies for almost 30 years. I'm quite familiar with finding the less traveled line. Unfortunately, so is everyone else who lives out here. So, eventually there is no smooth line until the county graders come thru, which is all too infrequently.

 

After adding weight to the corners with bigger/ heavier tires, I dont think the TRD OR bilsteins are optimal for higher speeds with more wheel weight. They felt great with the stock tires and wheels, then when added heavier tires it wasnt the same. Swapped shocks and springs and it smoothed it out again

 

When I'm on washboard roads for a short enough amount of time where airing down isn't an option I drive in an S pattern and it helps quite a bit.

 

Welcome to independent suspension. My 2013 JK was the same way. I find it best to drive slower. Solves the problems on washboards.

 

I just changed out the 20’s on my truck for 18’s and it made a world of difference. And that is running an e rated tire too! Had a comment on how smooth my truck was at 45 MPH on the washboards. I also have the Off-road package in mine.
Daisy

 

Sorry guys, this is effectively a 70 series Landcruiser, not just a Prado. It's built to take a load. If you're not carrying a load, just air down the rear tires.

For Toyota Newbies, there are 70 series (real) Landcruisers, then there are (lightweight) Prados. Here, literally, is a page out of my manual. (I have a 75)

 

A gravel road with washboard is not exactly " off road "

 

Wrong, drive faster.

 

This is very bad advice, IMO.

The kind of washboard I'm used to gets exponentially more dangerous the faster you drive over it.

And for those who continue to say "air down the rear tires", I'll repeat info you apparently missed in my OP. I'm only running 32 psi in my tires. Anything lower than that will result in sidewall and poor tread wear.

 

Can you tell me what kind of valving is in your factory shock?

You need to overcome your shim preload to get the shock to smoothen out. The only way to do that is go faster.

32 PSI for the street is fine, offroad you must (or definitely should) go lower. Even my setup, with a baller suspension doesn’t feel great on washboard at my street tire pressure. You said you drive it everyday, so here are your options: new tires and wheels or new shocks. Preferably both.

 

I don't know how you are even running that, when I ran Load E, I couldn't get below 43 PSI or so without the sides wearing out

I really think running Load E on 20"s is a big portion, at that wheel size and 10-ply there is just really not much sidewall to flex at all

 

1. Go fast. Over 40 smooths it out.

2. 20 PSI would help a ton.

 

As I said earlier, my current 20" wheels and tires have 1" less sidewall than my previous Tundra with 18" wheels and the same brand/size tire. Unless someone can provide more data than just opinion, I'm not convinced the 20" wheels are the biggest factor in the difference between the 2 trucks on washboard.

Sorry, but going faster does not smooth it out, only makes it more dangerous. It's clear many of you have no experience with the type washboard I'm talking about.

And, no, I'm not going to air down every day for the 7 mile trip to pavement, then air back up for the remaining trip. That's a ridiculous idea.

 

That's because you are on 20s. I run my 33" D-rated tires on 18" wheels at like 26 PSI (TPMS light in the morning). With Leer cap (~200 lbs, ~100-150 lbs camping gear, 70 lbs roof rack with mounts for 60 lbs canoe. 1500+ miles of gravel in a week, no flatties.

Speed kills, yes. Going 45 on gravel, maybe 50. It also does MPG magic, like 708 miles on a 38 gallon tank, not even empty.

 

Well, it does! Shocks have to work harder, they get heat soaked, energy absorption drops, wheels hop more, the ride feel "smoother". In reality you may end up in ditch because of loss of traction.

 

Thanks, it's difficult to tell, but the road in your video doesn't appear nearly as washboarded as our local roads get. Ranchers in my area are constantly hauling heavy trailers filled with livestock or machinery. I think that is a lot of the problem with our roads. The other problem is the county graders never really eliminate the washboard. Instead, they just pull loose dirt from the edges of the roads, and fill the washboard in. That literally lasts about a day, then the washboard is as bad as before.

That said, I agree that different shocks is most likely the solution that will make the most difference. I just need to figure out which shocks to buy. More suggestions for upgraded shocks on a Gen 3 Tundra with a standard suspension are welcomed.

 

ok, you asked for help and opinions, I gave you mine. So I'll bow out.

good luck

 

Sorry, Borla, I do appreciate your opinion, and I don't mean to come across ungrateful.

It's just that I've lived here nearly 30 years. I've always ran e-rated tires on all of the trucks I've owned in that time. This new Tundra is easily the worst handling of them all on the washboard. The 20" wheels are probably contributing to that some, but I'm not convinced it's the biggest factor.

I'll experiment with upgraded shocks, first. If that doesn't help, I'll bite the bullet for new wheels and tires.

 

If you're empty in back, you can easily air down to 25. Look at the sidewall rating and the empty weight on that axle (actually half for one side). For ease of calculation, if the tire is rated for 4000 lbs at 50 psi and your actual weight on that tire is only 2000 lbs, you should be running 25 psi, really 20 to 30 psi. 20 will give more compliance, 30 will give better mpg and tire life. Just don't forget to air up if you put a big load in the back - adjust accordingly.

 

Pull a drag on the road. Several old tires chained together, pulled behind truck.

A couple will get this, slow drag=fast cut.

 

When you say faster, you mean 25 instead of 15? You need to go fast enough so the tires aren’t dropping to the bottom of every rut. It may be the road layout or inexperience doesn’t let you get the speed where you observe the benefit - but going fast will certainly smooth it out - it’s physics.

 

Why not find a set of 18” takeoffs from an online marketplace for a reasonable cost and do your own butt dyno testing?

 

What did you switch out to?

 

These are county roads. They are maintained by county grading contractors. I don't think they'd take too kindly to me taking matters into my own hands. Besides, dragging a few tires wouldn't do squat to improve the washboard. It needs to be cut to flat ground, not just filled in with loose dirt. Our old county grader knew how to do it correctly, but he retired. The new guy doesn't. I pulled over once, when he was parked and having lunch, to politely suggest how it should be done, but he got offended over me telling him how to do his job. LOL!

The speed limit on these roads is 40 mph. The worst washboard occurs coming into and out of sharp corners were vehicles have to slow down coming into the corner, then accelerate out of the corner. It would be a recipe for disaster to try to fly around these corners faster than 10 mph.

 

no problem at all, good luck.

I did not notice a huge difference on the wash board roads up in northern MN that I go on between the older gen and this gen. There was a good improvement when I turned AVS to comfort mode so the gen 3 was a little better, I had to find the right speed more than anything to cut down the vibrations and frequency response.

it could also be as simple as the wheelbase difference, it may be that the wash board on your specific roads just makes it that your hitting the bumps at right frequency that makes it not ride and handle as well.

There is a patch of interstate here that my 2016 rode like absolute dog shit on, axle hope city due to the spacing (frequency ) of the bumps, and my gen 3 is smooth, partly due to the coils having way less axle hop and the AVS, but also because the wheelbase difference.

just random shit, play with the speeds though, (Im not saying fast either), thats free!

I know you didnt want sandbags, I used to have those on my gen 2.5 so I get that, but in the interim , it's cheap and will smooth it out. I had 300lbs I think in my 2016 to make it ride even half way decent.