Getting rid of the front end hop while towing

[ranchhopper]

I maintained a CDL for 30 years before I retired too, so I understand exactly what you're talking about. I've run into the same bobbing/hopping issue - it's the concrete slabs you're driving on. They are all exactly the same length and it is the long wheelbase of the truck in combination with the waves in the road (the uneven seam where the slabs join) setting up a resonant frequency and you get a lot of bounce. Changing the speed of the truck should help eliminate resonance. Probably 5-10 mph or more either up or down should be enough to break the cycle. The only trouble is that you will have to do that every couple of minutes because maintaining any speed over about 50 MPH for a long enough period of time will just allow it to start again.

Yeah pulling up a hill is worse when the truck is working harder.

 

[ranchhopper]

I maintained a CDL for 30 years before I retired too, so I understand exactly what you're talking about. I've run into the same bobbing/hopping issue - it's the concrete slabs you're driving on. They are all exactly the same length and it is the long wheelbase of the truck in combination with the waves in the road (the uneven seam where the slabs join) setting up a resonant frequency and you get a lot of bounce. Changing the speed of the truck should help eliminate resonance. Probably 5-10 mph or more either up or down should be enough to break the cycle. The only trouble is that you will have to do that every couple of minutes because maintaining any speed over about 50 MPH for a long enough period of time will just allow it to start again.

It stops as soon as I get off the concrete road onto the asphalt then it doesnt do it no matter what speed Im going I do think having better shocks may dampen it a bit though.

 

[Wire4money]

It stops as soon as I get off the concrete road onto the asphalt then it doesnt do it no matter what speed Im going I do think having better shocks may dampen it a bit though.

It’s a resonant frequency. The Silverados were horrible about it and had a TSB issued.

 

[Choupique]

Its driven by tongue weight and speed. The back shocks can't dampen the oscillations out, the whole thing starts rocking back and forth, and it devolves to the point of uncontrollable.

You either need stiffer springs, way more dampening, both which destroy unloaded ride quality, less tongue weight, or less speed.

This happens all the time towing my boat with my 2500. My friends F350 with the same wheelbase and the same boat can tow the same road at much higher speeds than my truck with no oscillations. Mine will start porpoising horribly over 57 or 58 mph. He can tow it any speed he wants on the same stretch with zero porpoising.

The difference is he is nowhere near max weight and has stiffer leaf springs. Mine is like 3 pounds below GVWR with coils.

 

[ranchhopper]

Its driven by tongue weight and speed. The back shocks can't dampen the oscillations out, the whole thing starts rocking back and forth, and it devolves to the point of uncontrollable.

You either need stiffer springs, way more dampening, both which destroy unloaded ride quality, less tongue weight, or less speed.

This happens all the time towing my boat with my 2500. My friends F350 with the same wheelbase and the same boat can tow the same road at much higher speeds than my truck with no oscillations. Mine will start porpoising horribly over 57 or 58 mph. He can tow it any speed he wants on the same stretch with zero porpoising.

The difference is he is nowhere near max weight and has stiffer leaf springs. Mine is like 3 pounds below GVWR with coils.

I figured it might have something to do with the coils as opposed to leaf springs.

 

[Docwagon1776]

I figured it might have something to do with the coils as opposed to leaf springs.

Somewhat. Coils allow for more flex and more deflection than leaves. But, if within proper weight, both are perfectly serviceable. Coils just don't like being 'at the edge' as much.

 

[Choupique]

The coils are just squishier. They also dont allow for an overload spring like leaf springs do.The suspension is probably the first ever put on a 3/4 ton that wasn't extremely overkill for the gvwr. They're great within the capacity of the truck, which is why I think OP is likely a little overweight and driving a little too fast for the conditions.

 

[DRam2019]

Former tow truck builder here. I used to install counter weight behind the front bumper on wreckers to combat this issue. Guys would say put in airbags, but they don’t help and I would tell them as much, after installing airbags they would come back complaining of same problem, and of corse would say I told you so.

Miller Light Duty Wrecker Universal Bumper Counter Weight

 

[David James]

I bought a new 2500 tradesman back in january and have used it to tow my skidsteer several times and it would like to beat me to death going down the road with the six thousand pound machine on the trailer. I never had the amount of front end hop this truck has Im not sure if its the coil springs or not I never had it with trucks with rear leaf springs. Its just on the concrete paved roads where the road is saw cut every so many feet to reduce the winter cracking of concrete and it causes a rythmic hop will heavier shocks in the front help this problem or is it just the nature of the beast given the coil springs and concrete paved roads.

Have you weighed what’s laying on the tongue? Wheel hop shouldn’t be happening if everything is within spec. Coil springs have zero to do with it.

 

[Andrei20]

As it was mentioned here the tongue weight could be excessive, but also comes in factor the length of the hitch. The shorter the better. The weight on the ball will have less leverage to act on your truck.
And yes, when your skidsteer sits mostly on the trailer axles instead of closer to the tongue and on the hitch, anytime it bounces up and down, it will bounce more on the trailer axles, and have less force to bounce on the hitch and rock your truck up and down.

 

[tron67j]

Former tow truck builder here. I used to install counter weight behind the front bumper on wreckers to combat this issue. Guys would say put in airbags, but they don’t help and I would tell them as much, after installing airbags they would come back complaining of same problem, and of corse would say I told you so.

Miller Light Duty Wrecker Universal Bumper Counter Weight

Yep, bags won't help at all, they just put a sheet over the monster but it's still there if the problem is too much weight at the rear. Really sounds like poor load distribution. I would get the loaded tongue itself on a scale, bet the skid steer is transferring way to much weight to the tongue.

Not sure if a WDH is an option on the type of trailer. And problem of moving skid steer back on trailer is that too much weight can be put behind trailer axles and then it becomes a fishtailing issue. Best solution may be to get a trailer that goes to a pin in bed of truck if that pin weight is not pushing truck over gvwr. Weight up front can also be an option as long as the total truck gvwr isn't exceeded with loaded trailer attached. But no matter what if the unit is shifted back on trailer OP has to keep the tongue weight of front trailer near equal to the theoretical "rear tongue" weight. This will prevent the fishtail and not shift to a problem of the trailer trying to lift the rear end of the truck up.

 

[Willie Mosher]

Have to you check wheel bearing?

Ram 2500 -5500 w 80k to 120k will need new wheel bearing.

Check tie rod and link as well,

 

[DRam2019]

I will add this to the convo for all bumper pull type towing. Air bags are useless for getting the front axle weight back on the axle, anyone that says different doesn’t understand levers and fulcrums. Only two things will help ( not including weight distributing hitch) more wheel base, or more weight located in front of the front axle. A crew cab with an 8’ bed will tolerate more tongue weight than a regular cab with the same 8’ bed —— lever is longer on the crew cab.

 

[Ecosqueasl]

I agree with the weight distribution as being the most likely issue, or overweight on the hitch.
I'd try getting the front of your trailer up just a little bit and move your machine back. I had the same issue on my 1500 and installed air bags simply to get the back end up higher. Don't know if it would make a difference in your situation but I had lowering springs in the rear so definitely helped there.

 

[Tulecreeper]

I agree with the weight distribution as being the most likely issue, or overweight on the hitch.
I'd try getting the front of your trailer up just a little bit and move your machine back. I had the same issue on my 1500 and installed air bags simply to get the back end up higher. Don't know if it would make a difference in your situation but I had lowering springs in the rear so definitely helped there.

But that does nothing to shift the weight, it only levels the body.

 

[Randy Grant]

ight even have something to do with the crappy road construction. They build many of them high at the joint.
Drive them unloaded and see if you notice anything.

 

[Ecosqueasl]

A vehicle always rides better with the nose lower than the rear, weight or no weight, the only way for you to shift your weight is on the trailer, or I have cut the hitch off already and drilled a new pin hole to shorten it. Gets the trailer hitch almost touching the bumper.

 

[quickster2]

When I load my 25" Gooseneck up I take a measurement of the hitch height empty. I try for about 3" of rear suspension compression prior to the rear air suspension leveling kicking in. This has worked well for me the past 8 years. I realize you don't have a gooseneck, without weighing your rig to know the tongue weight, you might want to try this approach. I used this similar approach to suspension loading (no rear air leveling) with my 2003 2500 V10 when I had it prior to the 2015. Find the sweet spot and go from there. Good luck.