Why does my truck 'fish-tail' so easily on gravel roads ?

[TSL]

Just spent a weekend camping on Steens Mtn in south eastern Oregon. Lots of driving on gravel roads. The main loop road up and over the mountain is a 59 mile stretch. It is a fairly decent gravel road,it is posted for 35mph speed limit and while you wouldn't want to take some of the sharper corners at that speed, plenty of it, including the hills, was quite straight and would be safe at that speed. I included a picture of the road and it can easily be navigated by small passenger cars. I've done it myself in the past in my Subaru. However, in my truck this time, I had several occasions where the back end lost traction and the truck began to sway / fish-tail on the road. It was bad enough that the ESC light in the instrument cluster flashed a couple times and was decidedly an unpleasant experience ! Happily there were no cliff edges present at the time.

I am a truck novice, this Rebel is my first truck, and I've a grand total of less than 2,500 miles driving experience ! So I'm open to any and all input as to what I'm doing wrong here!

I did notice this only happened when the road was going up a steeper grade and there was severe wash-board on the road ( which of course there generally was on the steeper sections ! )
I'm guessing that what's happening is one of the rear wheels is losing traction while the other is still gripping and pushing the truck forward. This would introduce a 'turning moment of force', right ? But since the front wheels aren't doing the same thing, the only thing that can happen is for the back end to sort of pivot side-ways. It's kind of like having rear-wheel steering when you're not expecting it !
I tried 2Hi, 4Hi and 4Auto, it happened in all those cases. Perhaps a little less so in 4Hi I think, but on at least one occasion it was bad enough in that configuration to make the ESC flash.
The only real way to avoid it was to slow down to less than 20mph on those grades. Let the truck just chug up the hill, and then it stayed firmly in control.
Is that the solution ? It just seems surprising that an "off-road capable truck" seems less capable on a gravel road than my Subaru Outback ! I feel like I must be doing something wrong !
The truck bed was not empty. I have a ~175lb roof top tent mounted on a bed rack, plus all my camping stuff in the bed. Do I need to chuck in a few 50lb chicken feed bags from the barn as well before I head out? Just kidding, but I'm thinking it must be something to do with not enough weight on the back of the truck to get traction going uphill ?
What about my tires ? I have the stock tires from the factory. I did notice the tire pressure looked on the high side. I've never added to nor removed air from the tires and I noticed they were reading from a low of 57 psi on one to a high of 66psi on another. That was while driving on a hot day. I know Overlanders often reduce air pressure when going off road, but I'm thinking that's on soft terrain not hard gravel road ?
By the way, with those tire pressures and the Rebel suspension, some of the washboard parts were terribly jarring, there were places I slowed to 15mph or less just because of the vibration.
Interested in any thoughts from the community on how I should be driving on gravel with washboard while keeping in control of the rig !

 

[Eighty]

Your truck has an e-locker. Have you tried locking the axle?

 

[Louhound88]

Just spent a weekend camping on Steens Mtn in south eastern Oregon. Lots of driving on gravel roads. The main loop road up and over the mountain is a 59 mile stretch. It is a fairly decent gravel road,it is posted for 35mph speed limit and while you wouldn't want to take some of the sharper corners at that speed, plenty of it, including the hills, was quite straight and would be safe at that speed. I included a picture of the road and it can easily be navigated by small passenger cars. I've done it myself in the past in my Subaru. However, in my truck this time, I had several occasions where the back end lost traction and the truck began to sway / fish-tail on the road. It was bad enough that the ESC light in the instrument cluster flashed a couple times and was decidedly an unpleasant experience ! Happily there were no cliff edges present at the time.

I am a truck novice, this Rebel is my first truck, and I've a grand total of less than 2,500 miles driving experience ! So I'm open to any and all input as to what I'm doing wrong here!

I did notice this only happened when the road was going up a steeper grade and there was severe wash-board on the road ( which of course there generally was on the steeper sections ! )
I'm guessing that what's happening is one of the rear wheels is losing traction while the other is still gripping and pushing the truck forward. This would introduce a 'turning moment of force', right ? But since the front wheels aren't doing the same thing, the only thing that can happen is for the back end to sort of pivot side-ways. It's kind of like having rear-wheel steering when you're not expecting it !
I tried 2Hi, 4Hi and 4Auto, it happened in all those cases. Perhaps a little less so in 4Hi I think, but on at least one occasion it was bad enough in that configuration to make the ESC flash.
The only real way to avoid it was to slow down to less than 20mph on those grades. Let the truck just chug up the hill, and then it stayed firmly in control.
Is that the solution ? It just seems surprising that an "off-road capable truck" seems less capable on a gravel road than my Subaru Outback ! I feel like I must be doing something wrong !
The truck bed was not empty. I have a ~175lb roof top tent mounted on a bed rack, plus all my camping stuff in the bed. Do I need to chuck in a few 50lb chicken feed bags from the barn as well before I head out? Just kidding, but I'm thinking it must be something to do with not enough weight on the back of the truck to get traction going uphill ?
What about my tires ? I have the stock tires from the factory. I did notice the tire pressure looked on the high side. I've never added to nor removed air from the tires and I noticed they were reading from a low of 57 psi on one to a high of 66psi on another. That was while driving on a hot day. I know Overlanders often reduce air pressure when going off road, but I'm thinking that's on soft terrain not hard gravel road ?
By the way, with those tire pressures and the Rebel suspension, some of the washboard parts were terribly jarring, there were places I slowed to 15mph or less just because of the vibration.
Interested in any thoughts from the community on how I should be driving on gravel with washboard while keeping in control of the rig !

Yeah sounds like just a lack of traction in the back from tire pressure being too high.

That's some pretty high tire pressure. What does your door sticker say? I know Rebels seem to list a high tire pressure for some reason, but it's not as if the truck weighs enough on it's own to warranty the high pressure.

In 2hi you'll get some fish tailing on a gravel road, but mostly if you try to get on it or give a little too much gas pedal. 4auto I find is best for rainy road driving, as it helps keep you from spinning when turning, but even then on highway/straight stretches it'll switch back to 2hi so you'll still have the risk of hydroplaning or hitting an oil/slick spot and losing rear wheel traction.

On a gravel road or any other soft/loose terrain you'll want to put it in 4hi. If you have lots of turns but the terrain isn't quite loose enough, you may feel resistance when trying to steer. So you want to make sure you're on loose enough stuff to let it slip and allow you to turn. Otherwise you may understeer and possibly run off somewhere you don't want to be lol. In that case 4 auto is best.

But in 4hi, loose road, punch it, you should basically crab walk. All 4 wheels spin, break loose, but you'll be going straight. Straight enough to steer and control, give you time to ease out of the throttle and dial in how fast you can drive on whatever surface without sliding too much.

I have yokohama M/T tires, 12 ply, etc. I run mine around 36 when street diving and if I pre-plan some offroad driving i'll drop pressure to maybe 30 or 32. But it's rare that I go off road and even more rare that I plan it out lol. If I plan to drive on the beach, i'll drop them down to maybe 28 or so, and keep it in 4hi once on the sand. But otherwise I keep my pressure for road driving.

 

[TSL]

Your truck has an e-locker. Have you tried locking the axle?

I thought of that...pushed the button and it said "not available" ( or something ). Later, back at my campsite I poked around in the manual ( when all else fails ! ;-) and learned that in 4Hi you have to be going less than 20mph for the locker to work, or in 4Lo up to 40mph. Since slowing to <= 20mph seemed to do the trick anyway, I never actually tried engaging the axle lock.

 

[TSL]

Yeah sounds like just a lack of traction in the back from tire pressure being too high.

That's some pretty high tire pressure. What does your door sticker say? I know Rebels seem to list a high tire pressure for some reason, but it's not as if the truck weighs enough on it's own to warranty the high pressure.

In 2hi you'll get some fish tailing on a gravel road, but mostly if you try to get on it or give a little too much gas pedal. 4auto I find is best for rainy road driving, as it helps keep you from spinning when turning, but even then on highway/straight stretches it'll switch back to 2hi so you'll still have the risk of hydroplaning or hitting an oil/slick spot and losing rear wheel traction.

On a gravel road or any other soft/loose terrain you'll want to put it in 4hi. If you have lots of turns but the terrain isn't quite loose enough, you may feel resistance when trying to steer. So you want to make sure you're on loose enough stuff to let it slip and allow you to turn. Otherwise you may understeer and possibly run off somewhere you don't want to be lol. In that case 4 auto is best.

But in 4hi, loose road, punch it, you should basically crab walk. All 4 wheels spin, break loose, but you'll be going straight. Straight enough to steer and control, give you time to ease out of the throttle and dial in how fast you can drive on whatever surface without sliding too much.

I have yokohama M/T tires, 12 ply, etc. I run mine around 36 when street diving and if I pre-plan some offroad driving i'll drop pressure to maybe 30 or 32. But it's rare that I go off road and even more rare that I plan it out lol. If I plan to drive on the beach, i'll drop them down to maybe 28 or so, and keep it in 4hi once on the sand. But otherwise I keep my pressure for road driving.

I just looked again at the tire pressures : I've got 56 / 55 on front and 54 / 60 at the back. This is sitting in my garage for the last 20 hours, ambient temperature is 80 F.
I looked at my tire / loading sticker : it says 55 front and 45 rear. Whoops ! I might have found my problem perhaps, one of the rears is 9 over and the other 15 PSI over recommended !
The fronts are more or less correct. I haven't done anything to the tires since I got the truck. As I type this I do now vaguely recall reading somewhere that the factory ship them with elevated pressure, something to do with if they are sitting around for a while it's better that way ?
Anyway, I think I'm going to lower those rear tires and try some gravel roads again. It'll not be Steens mountain though, that's 7 hours away from me !

 

[HSKR R/T]

I just looked again at the tire pressures : I've got 56 / 55 on front and 54 / 60 at the back. This is sitting in my garage for the last 20 hours, ambient temperature is 80 F.
I looked at my tire / loading sticker : it says 55 front and 45 rear. Whoops ! I might have found my problem perhaps, one of the rears is 9 over and the other 15 PSI over recommended !
The fronts are more or less correct. I haven't done anything to the tires since I got the truck. As I type this I do now vaguely recall reading somewhere that the factory ship them with elevated pressure, something to do with if they are sitting around for a while it's better that way ?
Anyway, I think I'm going to lower those rear tires and try some gravel roads again. It'll not be Steens mountain though, that's 7 hours away from me !

Just having that big of a difference side to side in the rear is a problem as well. Definitely drop them down.and make them even.

You should be able to get around in that road in 2wd just fine. And I'd probably be doing 60mph in the straightaways myself, but I grew up in gravel roads.

 

[Sascwatch]

Drop the pressures down to the recommended 55/45 and it’ll be much better. Having some weight in the back will help, all trucks are light in the rear and will break traction easily with the power/torque they put out.

While using the locker you will get a bit more traction in the rear, but things will be worse when both wheels break loose. At high speeds this is a bigger issue which is why the truck limits the speed the rear stays locked.

Overtime you will get used to how much/little throttle you can apply before the wheels break free, I like to keep the truck moving and coast up hills as much as possible. Always in 2wd unless there is snow on the roads.

 

[WXman]

A lot of it is because of the horrendously stupid coil spring 4-link suspension Ram uses on pickups. This design requires an anti-sway bar and a track bar, sometimes called a Panhard bar. Those two bars keep the axle rigidly in place laterally AND they try to keep it from articulating much. The effect is that it's great on a nice smooth highway but it completely sucks for everything else.

I've had more trucks than I could swing a dead cat at. I'd take leaf springs any day of the week.

 

[Rick3478]

You're on point with the "turning moment" concept, but also because it is a pickup truck designed to tow and haul cargo, designers chose a beam axle as the most cost effective way to get the increased strength needed for those tasks (relative to the independent front suspension). So you get higher unsprung weight and poorer compliance, which results in loss of traction on bumpy surfaces. With a load in the bed, it gets better up to a point.

 

[Louhound88]

A lot of it is because of the horrendously stupid coil spring 4-link suspension Ram uses on pickups. This design requires an anti-sway bar and a track bar, sometimes called a Panhard bar. Those two bars keep the axle rigidly in place laterally AND they try to keep it from articulating much. The effect is that it's great on a nice smooth highway but it completely sucks for everything else.

I've had more trucks than I could swing a dead cat at. I'd take leaf springs any day of the week.

Leafs are good with loaded beds and hitch weight. But unloaded driving I much prefer the coil link rear end Ram has.

Articulation with a 4 link rear and sway bar is still better than leaf springs. Only time I find the rear suspension lacking is when i'm hauling a bunch of stuff in the bed or towing something. End up with lots of rear squat. Can always add some quick sway disconnects if you like the trophy truck body roll lol.

 

[Shots]

Well the things I see.
First is the tires. Over pressured is not helping at all. I typically run around 40-45 psi. 55-60 is killing you.

The Ram obviously has a higher center of gravity than the Subaru. That higher COG is "tipping" the truck whether it's enough to see/feel or not. When this happens, however little, you're taking some of the grip away from the inside tire(s) and forcing the outside to do all the gripping. A lower vehicle will be able to corner better/faster than a tall one.

The Subaru is all wheel drive, (and they're good at it) so it may compensate for loss of traction from individual tires better. To have the most comparable driving experience I'd think the 4 auto setting would be best.

You might not be used to the power of the Ram. These things are beasts, and it takes very little throttle to get it going (or spinning). You may be accustomed to a heavier throttle demand, and are just giving it too much power.

Washboards and bumps don't help a truck either. The back ends are light, even with a load. They'll skip around pretty easy, especially when accelerating. It takes a little time to get used to how they feel and how to keep it from stepping out. This is particularly true when you're coming from an awd vehicle that has a front to rear weight distribution closer to 50/50.

Get more time behind the wheel of it and let some air out of those overinflated tires. You'll be fine.
If the front tires aren't sliding straight through the curve, there is sufficient traction to go the speed you were. Oversteer (fishtailing) is typically a driver input issue. You'll adapt to the new ride and figure out how to get the most from it.

 

[Louhound88]

I just looked again at the tire pressures : I've got 56 / 55 on front and 54 / 60 at the back. This is sitting in my garage for the last 20 hours, ambient temperature is 80 F.
I looked at my tire / loading sticker : it says 55 front and 45 rear. Whoops ! I might have found my problem perhaps, one of the rears is 9 over and the other 15 PSI over recommended !
The fronts are more or less correct. I haven't done anything to the tires since I got the truck. As I type this I do now vaguely recall reading somewhere that the factory ship them with elevated pressure, something to do with if they are sitting around for a while it's better that way ?
Anyway, I think I'm going to lower those rear tires and try some gravel roads again. It'll not be Steens mountain though, that's 7 hours away from me !

Yeah, 60 in the rear is a lot and you should feel it drives alot smoother on roads too. More controlled rear end and not as much rear end hop on bumpy roads and potholes.

But then again jamb stickers give payload rating (yours is 1396 i think) so that tire pressure still may be high for unloaded driving. Factor in how much you weigh, the weight of your passengers, and the weight of the stuff in your bed, and you can somewhat dial in your tire pressure for improved ride.

 

[HSKR R/T]

Well the things I see.
First is the tires. Over pressured is not helping at all. I typically run around 40-45 psi. 55-60 is killing you.

The Ram obviously has a higher center of gravity than the Subaru. That higher COG is "tipping" the truck whether it's enough to see/feel or not. When this happens, however little, you're taking some of the grip away from the inside tire(s) and forcing the outside to do all the gripping. A lower vehicle will be able to corner better/faster than a tall one.

The Subaru is all wheel drive, (and they're good at it) so it may compensate for loss of traction from individual tires better. To have the most comparable driving experience I'd thing the 4 auto setting would be best.

You might not be used to the power of the Ram. These things are beasts, and it takes very little throttle to get it going (or spinning). You may be accustomed to a heavier throttle demand, and are just giving it too much power.

Washboards and bumps don't help a truck either. The back ends are light, even with a load. They'll skip around pretty easy, especially when accelerating. It takes a little time to get used to how they feel and how to keep it from stepping out. This is particularly true when you're coming from an awd vehicle that has as front to rear weight distribution closer to 50/50.

Get more time behind the wheel of it and let some air out of those overinflated tires. You'll be fine.
If the front tires aren't sliding straight through the curve, there is sufficient traction to go the speed you were. Oversteer (fishtailing) is typically a driver input issue. You'll adapt to the new ride and figure out how to get the most from it.

Another thing to consider is wheel base. The Subaru has a shorter wheel base, combined with even weight distribution, softer suspension being a car, and a superior AWD system, the washboards won't effect it as much, and it will be much harder to "fishtail" it.

 

[Ex_dutch]

Looking at the picture of the road… What I have noticed a few times, is that the “tracks” in the road sometimes try to toss me around, but I’ll have to do 55+ mph. I usually just put the truck in 4h to keep traction.
Unintentionally, my 1.5” wheel spacers seem to help by not getting trapped in a track as easily.

 

[TSL]

Well the things I see.
First is the tires. Over pressured is not helping at all. I typically run around 40-45 psi. 55-60 is killing you.

The Ram obviously has a higher center of gravity than the Subaru. That higher COG is "tipping" the truck whether it's enough to see/feel or not. When this happens, however little, you're taking some of the grip away from the inside tire(s) and forcing the outside to do all the gripping. A lower vehicle will be able to corner better/faster than a tall one.

The Subaru is all wheel drive, (and they're good at it) so it may compensate for loss of traction from individual tires better. To have the most comparable driving experience I'd thing the 4 auto setting would be best.

You might not be used to the power of the Ram. These things are beasts, and it takes very little throttle to get it going (or spinning). You may be accustomed to a heavier throttle demand, and are just giving it too much power.

Washboards and bumps don't help a truck either. The back ends are light, even with a load. They'll skip around pretty easy, especially when accelerating. It takes a little time to get used to how they feel and how to keep it from stepping out. This is particularly true when you're coming from an awd vehicle that has as front to rear weight distribution closer to 50/50.

Get more time behind the wheel of it and let some air out of those overinflated tires. You'll be fine.
If the front tires aren't sliding straight through the curve, there is sufficient traction to go the speed you were. Oversteer (fishtailing) is typically a driver input issue. You'll adapt to the new ride and figure out how to get the most from it.

I'm probably tilting the COG a little higher still by adding the roof top tent - that's 173lb up there ( see pic ).
Notwithstanding that the Subaru has some better handling capability in some cases ( that's one of the reasons I decided to keep it after getting the truck ), I still love the truck, there' so much I can do with it that the lil' Subaru just can't. Even little things, like going camping, I can stop where-ever I want and I have a built in picnic table ( the tail gate ! ).
Yeah, I just need to get more familiar with it, and get it dialed in right, like the tires for example ! But I gotta tell you, being a truck newbie, and having this big beast fish tailing on a gravel road up the mountains -hooo-boy ! I'm just glad it wasn't on a stretch with a real scary drop off. There were stretches like that elsewhere on the road and I took those nice and gently after that !
The picture is at the Kiger Gorge over-look on Steens Mountain in south eastern Oregon.

 

[SD Rebel]

Usually they are shipped with 65 psi to prevent flat spotting as they sit on lots for some time. The dealer often forgets before delivery to adjust them down.

The 55F / 45R for the Rebel is fine on paved roads, but I would drop them down to 35 F&R for extended dirt road driving, and 23 F&R for most off-roading situations, right up to light sand.

 

[boogielander]

as others have mentioned, air down will help.
Another thing is for washboard surface, the faster you go the more smooth it will get. This is because you're skipping through the dips and stuff instead of going over them. Fastest I've gone is around 70-75MPH going down gravel road, and the ride is as smooth as going down the 405. I should also mention that I was on King shocks when I was going that fast.

Also, avoid giving it too much beans if you can. Sometimes you push the gas pedal too hard and you're skipping through the dirt you will lose traction (hence ESC light). Try to give consistent throttle input and be smooth.
Slight fish-tailing is normal in my experience, and it can be controlled. To me, this side-to-side movement has a rhythm and all I had to do was to control it. I learned this after doing this for almost every weekend in 2020 lol

 

[Bt10]

A lot of it is because of the horrendously stupid coil spring 4-link suspension Ram uses on pickups. This design requires an anti-sway bar and a track bar, sometimes called a Panhard bar. Those two bars keep the axle rigidly in place laterally AND they try to keep it from articulating much. The effect is that it's great on a nice smooth highway but it completely sucks for everything else.

I've had more trucks than I could swing a dead cat at. I'd take leaf springs any day of the week.

You said "rigidly" - . Towing, I'd love to change all the rubber for at least urethane, johnny joints, or heims. Which is why I also have loved my leaf spring trucks towing.

 

[Sascwatch]

You said "rigidly" - . Towing, I'd love to change all the rubber for at least urethane, johnny joints, or heims. Which is why I also have loved my leaf spring trucks towing.

Core 4x4 makes some nice replacements for the factory suspension arms.

 

[HemiDude]

A lot of it is because of the horrendously stupid coil spring 4-link suspension Ram uses on pickups. This design requires an anti-sway bar and a track bar, sometimes called a Panhard bar. Those two bars keep the axle rigidly in place laterally AND they try to keep it from articulating much. The effect is that it's great on a nice smooth highway but it completely sucks for everything else.

I've had more trucks than I could swing a dead cat at. I'd take leaf springs any day of the week.

IMO - The coil spring setup is THE thing that separates the Ram from the others. Interior is good too. If I wanted a different suspension and could have settled for less comfort I would've bought a GMC truck.