Shock Absorbers For the Extra Weight of a Camper

[ski3pin]

JHanson recently made this post in another thread - that I did not want to hijack.

As has been mentioned, if you plan to remove the camper between trips, air bags are the only way to retain control and a decent ride both loaded and unloaded. If you plan to leave the camper on permanently, a properly specced spring pack is the way to go. I'm not fond of simple add-a-leaf kits as they can create stress risers in an otherwise well-distributed spring set. I also do not like Sumo springs and other glorified bump stops. It's worth the investment in comfort and safety to install a suitable kit from Deaver or another specialist. You'll also want shocks suitable for the extra weight.

I drive a midsize truck. How do I look for shocks suitable for the extra weight? I see all kinds of claims about better performance, but ability to handle weight is not mentioned - at least that my aging eyesight is able to see.

I, and maybe others, could benefit from a discussion on shocks for handling the extra weight we add to our trucks.

 

[Wandering Sagebrush]

I suspect there is a herd of us who would benefit from that discussion. In my case, I’d like to know if there are shocks that not only handle the extra weight, but also don’t contribute to a rougher ride when the camper is off the truck.

Thanks for starting the discussion!

 

[ckent323]

For those who do not already know, shock absorbers control the leaf spring, coil spring or air bag movement of your vehicle. Shock absorbers help keep tires in contact with the road surface by controlling the compression and rebound from dips and bumps in the road surface.

Ignoring tires for this discussion - The springs (or air bags) carry the weight of the vehicle and set the overall firmness or softness of the 'ride'.

Importantly - Shocks will not change the carrying capacity or weight rating of your truck. Shocks are not a cure for an overloaded or worn out suspension.

Shock absorbers typically can handle a fairly wide range of weights. However, there are different models of the same line of shock absorbers that are designed to cover higher or lower weight ranges. Of course the manufacturers have basic lines of shocks for use on pavement as well as higher lines of shocks for say occasional rough road or for rebuildability or some other performance feature.such as high heat dissipation for lots of rough road use.

It makes sense to understand the capacity range of your shocks to be sure that they cover the range of weights your truck is supporting. The best way to do this is to have your truck weighed at a public scale both completely loaded and completely unloaded. I recommend weighing each axle as well as the entire truck. One can get a reasonable estimate by looking up the weight rating for the specific model vehicle you have and then add to that the weights of various add on items as well as passengers, all gear, water, food and fuel (since the weight ratings are almost always given as dry weight (no fuel radiator water, etc.)

Higher performing shocks often employ various methods to more effectively dissipate heat since heat can damage a shock as well as degrade its performance during operation as it heats up. For example the frequent bouncing from driving down a washboard road can seriously heat up a shock and even cause it to fail unless it is designed for that kind of use.

Shocks are available in stock lengths for specific brands and models of vehicles in original configuration. Shocks are also available in a wide range of other off the shelf and custom lengths (fully extended and fully compressed) so that modified or custom vehicles are able to find shocks of appropriate lengths.

Shock valving controls the damping (speed of rebound) and on more expensive shocks there are often valving options that you can choose from. Choosing valving should be done with advice from someone who understands valving and how your truck will be used (after talking to you0.

Talk to a couple of local shops that offer shocks. In addition, most shock manufacturers will accept questions from customers who email the info on their truck including details about year, make, model, if it has been lifted, what extra weight it is carrying and how often as well as what kind of use it gets, say XX% on road and YY% graded dirt or maybe YY% washboard/rough offroad or whatever.

The Bilstein technical rep provided helpful information when I was seeking a higher performing shock after replacing my leaf springs and raising the truck 2". I wound up using 5100 series after measuring my trucks axle travel fully loaded and fully unloaded (you need a lift to do this) so I could order the appropriate length shock (extended and compressed lengths). I also was able to select from a couple of valving options based on my particular use profile for my truck.

Disclaimer:I learned a lot reading up on suspension, talking to experts and then working on my truck's suspension but I am by no means and expert on this stuff. Best to talk to a pro.

I hope this is helpful,

Craig

 

[Casa Escarlata Robles Too]

Craig thanks for all the info.
Frank

 

[Vic Harder]

Great info Craig. I'm confused about this statement "It makes sense to understand the capacity range of your shocks to be sure that they cover the range of weights your truck is supporting." I thought you said that the weight of the vehicle does not affect the shocks. The shocks are dealing with the unsprung weight of the tires/wheels/control arms, and the SPRINGS are dealing with the weight of the vehicle. Did I get that right?

 

[ski3pin]

Great info Craig. I'm confused about this statement "It makes sense to understand the capacity range of your shocks to be sure that they cover the range of weights your truck is supporting." I thought you said that the weight of the vehicle does not affect the shocks. The shocks are dealing with the unsprung weight of the tires/wheels/control arms, and the SPRINGS are dealing with the weight of the vehicle. Did I get that right?

I'm confused also (not too much of a surprise ). I don't believe I've seen "capacity range" listed on shock absorber specifications.

 

[pvstoy]

Shocks are attached at the axel and the frame of the vehicle. Yes the shocks are designed to control the unsprung weight of tires and axels going up and down. Also shocks are controlling the vehicle going up and down also even if the axel and tires are not moving much.

So in design match for vehicle the shock has the biggest chore controlling, damping the unsprung forces and not mentioning much some of the bounce rebound of the body. Yes the springs support the load of the body but shocks also dampen the force of the body helping the springs.

It is not mentioned much of the shock design to control the body just more focus controlling rebound of the unsprung weight of the vehicle. A shock deign has both features in the design for the vehicle. You may never see anywhere buying shocks the information you ask.

People that modify by adding much larger tires, or just more unsprung weight will need a different shock than stock to handle this. So the new beefier shocks can also handle sprung weight.

We add weight like a camper even though we are still under the load rating, the rear sags a bit. Do a suspension mode to carry the weight better, Ok the shock are still designed for the truck as the shocks are still working well for the tires and axles as they did not change much toward the unsprung weight of the vehicle.

Add air bags. If plumbed separately they really do add to the effort of the shocks to dampen. You think about it the airbags are mounted the same way as a shock absorber.

Ok I'm just been rambling not typing to precise in the verbiage.

Ski... if you just added support mod to hold up the camper weight and did not go extreme bigger tires etc.. then the stock shocks are fine. But I have always went with replacement Bilstein shocks (the ones sold for my vehicle) for a better performance and heat valving for those darn washboard roads. Those roads sure do work a shock hard and the heat kills off the manufactures stock shocks.

I'm sure there are more questions and only more confusion. I may have just added to it Cheers, Patrick

Note to self... should I proof read this???

 

[Dadocut]

When I replaced the shocks on my F250 w/ Hallmark Guanella, I replaced the stock shocks with Rancho RS9000XL adjustable shocks. I set them to the stiffest setting.

I think of shocks as dampeners for the springs. In my case the springs are leaf springs and air bags. With the weight of the camper on most of the time, I need a shock with a higher dampening factor, hence why I set the shocks to the stiffest setting. I've always wondered if I should have something a bit stiffer. The camper can bounce quite a bit when climbing over rocks. You definitely need stiffer shocks when traveling rocky roads with a camper.

What other stiffer shocks are out there? I don't do high speed washboard all that much so I don't think I need a shock with a separate reservoir. And how often do folks replace shocks?

Everyone talks springs and airbags. It's good to see a discussion on shocks.

 

[ckent323]

Vic, et al.

I think you misunderstood what I was trying to convey or maybe I failed to adequately explain what I meant.

Shocks are designed for a range of weights so that they are not say mostly or fully compressed by the unloaded or partially loaded vehicle or, conversely, not compressed at all even with a partially loaded vehicle.

The shocks need to be able to have some amount of action when the truck is unloaded and still have action when the truck is fully loaded.

So the shocks for a 2500 pound passenger car will probably have have a different range of weights it can support and effectively operate within than say a light truck weighng 5,000 pounds or medium weight truck weighing 10,000 pounds. The same shock will not work for all of those cases.

I hope that makes sense.



Pvstoy,

The following is an excerpt from the link below:

"...a Shock absorber’s sole purpose is to dampen the compression and rebound of any suspension system by controlling the speed at which a suspension cycles. Without them, your truck would continue to bounce up and down until the kinetic energy is finally dissipated from the suspension’s springs (e.g. leaf springs, coil springs, torsion bar, etc.).

Here is a link to an article that may do a better job of explaining what shocks do.

https://www.4x4review.com/everything-you-wanted-to-know-about-shock-absorbers/


Dadocut,

A nit I believe the correct term is damp (to stop oscillations) not dampen (to wet) although as in the link above dampen is very often used. I was often corrected by Mechanical Engineers about these terms during my career but in may be they are accepted as interchangeable. Never-the-less I have been reminded so many times over my career that to stop oscillations is to damp and to make something wet is to dampen that I am compelled to comment. I would not be surprised If I am among a very few for which this is a nit. ;-)

Also, I think you may be talking about adjusting the valving, which controls how fast or slow the shocks compress and rebound. I think it is synonymous with stiffer and softer. I am not familiar with adjustable Rancho shocks so I do not know if by stiffer that means the valving is somehow adjusted but I think so.

https://www.shocksurplus.com/blogs/shocks-101/adjustable-shock-absorbers-in-action



Regards,

Craig

 

[Dadocut]

You're right Craig. The correct term is to damp, not dampen, the oscillating mass. I too often speak loosely.

The Rancho adjusts with a small dial, I assume it's opening/closing a valve inside the shock.

 

[pvstoy]

I used the adjustable Rancho shocks, they worked but had to reach at the shocks to turn the knob.

Rember when you would push on the fender a few times hard downward and release to see if it would continue to bounce. Or watched a vehicle go over a parking lot speed bump and the body of the car would continue to bounce. That is showing that a shock does support the body and control bounce.

It will show up as cupping on the outside edge for tire wear.

 

[craig333]

My buddy drove his CJ4B around with no shocks and you could hardly tell. I had the adjustable ranchos and I got rid of them. Rides much nicer with the Bilstein 5100s.

 

[SunMan]

This is the best video I’ve found explaining suspension, it’s long but informative…

 

[Mighty Dodge Ram]

I chased after shock performance on the old Dodge using everything from KYB to Ranchos 9000 to Fox...my OCD got the better of me, especially with the adjustables. LOL I've settled on Bilsteins, both the 4600 (stock) and 5100 (taller for lifted apps). They just work. There is a discussion point regarding mono vs dual tube/chamber for our application. I know J Hanson has done some research/testing in this regard.

 

[ckent323]

Sunman,

Thanks for posting the Filthy Motorsports video it is most informative.

Craig

 

[craig333]

That was well worth spending an hour. I agreed with most of what he said and the rest is stuff I just don't know about. He'd probably tell me with my budget and needs just go with what you got. I'd like a 2" lift but do I really need one? Probably not. Heck, its got me where I want to go for twenty years the way it is why mess with it. Plus, as I get a bit long in the tooth I've also slowed down my driving a bit

 

[ski3pin]

I used the adjustable Rancho shocks, they worked but had to reach at the shocks to turn the knob.

Rember when you would push on the fender a few times hard downward and release to see if it would continue to bounce. Or watched a vehicle go over a parking lot speed bump and the body of the car would continue to bounce. That is showing that a shock does support the body and control bounce.

It will show up as cupping on the outside edge for tire wear.

I believe - in a different thread years back - a knowledgeable WTW member stated the same. Could we please have an explanation of this?

 

[smlobx]

Great topic and one that I am woefully uneducated on.

Just as a point of reference shortly after I bought my F-350 I felt the ride wasn’t properly damped. On the advice of my local shop I replaced the OEM shocks with Bilstein 5100’s and have been satisfied for over 75K miles. They come with a lifetime warranty btw.

I also have a Jeep Gladiator Rubicon that I have outfitted to overland with and of course this involves adding weight to the bed. These trucks are notoriously softly sprung and are borderline unsafe at highway speeds when you drive over corrugations at 75 mph.
In looking at how best to upgrade the suspension I have decided to get the AEV dual sport suspension package which includes a bunch of components ALL designed to work together which I appreciate. In their description they state that the kit includes Bilstein 5100 shocks that have been re-valved to work together with the upgraded shocks. This is exactly what I’m looking for.

 

[Beach]

I've run Bilstein 4600 series on my 2006 Tundra and my F250, both trucks carried the Hawk camper full time. I was completely happy with their performance on both vehicles. Bilstein also makes a 5100 series shock that is designed for lifted trucks or higher cg vehicles or running oversized tires etc. Below is a article on the difference between the shocks mentioned. I opted for the 4600 as I mostly drive graded forest service roads and paved roads,(no hardcore off road).

https://www.shocksurplus.com/blogs/shocks-101/bilstein-4600-vs-5100-series-what-are-the-major-differences

 

[craig333]

Bilstein 5100's can be used on a stock unlifted vehicle. I made sure before I purchased and installed them.