Washboard Dirt Roads = Major Problems

[Loufish]

The rear end handling is probably the most criticized issued discussed here about a brand new truck....This starts because about 1/2 or more Raptors are delivered "ready" to the customer with way to much air pressure all around, but the rear end is very picky on what it needs...then add some excessive rear axle wrap and you have all that's needed to convince any new owner that Ford engineers DIDN"T complete the truck....

Get that rear air pressure down...if the truck is empty 32 psi will work pretty good...

 

[mezger]

I'm surprised Deavers haven't already also been mentioned.

 

[2018RubyRed]

The early build 19s h(before November 15, 2018)a message about rough ride. Supposed to update the module that controls the shocks. Look up ssm 47757

 

[jzweedyk]

The Raptor is NOT the only vehicle that needs to have the pressure lowered. Having many Jeeps I can assure you that if you leave the tires at street pressure and race down a washboard road you will get the same feeling, maybe worse. So if you don't want to lower it, then you will suffer the consequences. If you want to drive at 5 mph, you will be fine. Just like putting it in 4 wheel drive, going off the pavement requires some adjustments. I run 34 front and 32 rear (cold) on road with great results, and go down to 14 if I am going in sand or rocks. Mid 20s are fine for washboard. It amazes me that so many people are afraid to lower their pressure. Radial tires can handle it, unless you are going very high speed on a really hot day. Pavement is hotter than dirt and tires heat up faster on pavement. Ideally, when you switched it to sand/mud or rocks, the truck would adjust the pressure for you, like it adjusts the shocks and shift points, but it just doesn't work like that.

As further proof, if you don't believe me, blow you tires up to 50 and take it out for a drive on pavement, the rear end will be skittish then, and the reverse is true. Let air out and it will ride better.

 

[rtmozingo]

Helpful, thanks guys.

So what I'm hearing is that the Raptor requires PSI adjustments, while pretty much every other car, SUV and truck on the road can tackle this stuff without a problem. I can appreciate that, actually, as the Raptor is a different beast.

Just so we're clear, these were county back roads, not offroad trails. They're probably plowed in the winter and otherwise maintained periodically. We're talking paved road for a mile, dirt road for a stretch, and then back on pavement. There was a group of bikers who passed us on Harleys going about 35. So offroad really isn't the right term for the terrain that was causing her problems.

I hit a similar road a few weeks back with tires at 35f/32r and was fine. Gotta be below 33 in the rear tho at least

 

[PDT905]

The Raptor is NOT the only vehicle that needs to have the pressure lowered. Having many Jeeps I can assure you that if you leave the tires at street pressure and race down a washboard road you will get the same feeling, maybe worse. So if you don't want to lower it, then you will suffer the consequences. If you want to drive at 5 mph, you will be fine. Just like putting it in 4 wheel drive, going off the pavement requires some adjustments. I run 34 front and 32 rear (cold) on road with great results, and go down to 14 if I am going in sand or rocks. Mid 20s are fine for washboard. It amazes me that so many people are afraid to lower their pressure. Radial tires can handle it, unless you are going very high speed on a really hot day. Pavement is hotter than dirt and tires heat up faster on pavement. Ideally, when you switched it to sand/mud or rocks, the truck would adjust the pressure for you, like it adjusts the shocks and shift points, but it just doesn't work like that.

As further proof, if you don't believe me, blow you tires up to 50 and take it out for a drive on pavement, the rear end will be skittish then, and the reverse is true. Let air out and it will ride better.

Fair enough. I'm coming from an old 4Runner that has never once had its tires aired down, which I drove for 210k miles on every road and in every condition imaginable before upgrading to the Raptor. So my recent experience is very limited and I probably should have been more careful with that statement. Even so, none of the other 50 vehicles in the area were pulled off to the side adjusting tire pressure.

The Raptor just seems to be a whole lot more sensitive to changing road conditions than most vehicles I've driven. I find that counter-intuitive for this particular truck. It's like buying a 5,000 dollar set of skis only to find out that they are the worst pair on the mountain unless you wax the **** out of them between every run.

There's clearly a learning curve here. I appreciate the help and feedback.

 

[Schizofilly]

Worth noting in addition to the tire psi, the more you press that skinny pedal on the right the more it will smooth out. I run roads like you are talking about daily for work. Anything less than 45 mph and the suspension just doesn't shine. I know that speed isn't reasonable in all situations and some buzz kills will say you shouldn't go that fast on dirt that's not a closed course, but if I drove 5 mph on dirt I'd never have time to sleep.


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[rtmozingo]

Worth noting in addition to the tire psi, the more you press that skinny pedal on the right the more it will smooth out. I run roads like you are talking about daily for work. Anything less than 45 mph and the suspension just doesn't shine. I know that speed isn't reasonable in all situations and some buzz kills will say you shouldn't go that fast on dirt that's not a closed course, but if I drove 5 mph on dirt I'd never have time to sleep.


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That's a good point too. These shocks have a massive range of conditions they have to cover, and therefore can be picky in how they react unless you dial in the speed. Going faster often does smooth things out.

It also should be noted this problem exists with all the modern F150s, not just the Raptor. Light bed, high torque, and leaf springs all contribute.

 

[PDT905]

Are there any drawbacks or trade offs associated with adding traction bars and Deaver/Icons?

I understand there is an associated cost.

 

[dewalt]

Saw a iTunes video of an Australian ranger raptor. Drag links and coils on the back