Changing out the STD 5th wheel ????

[alan0043]

2 hours ago, HERO Maker said:

I missed Brit's talk at the ECR this past year, and it would be wonderful is someone were to dial in what our spring rate should be and the dampening and rebound rates of the shocks should be.  Obviously since all of us (with the exception of some special order trucks) are/were set up for heavy loads (a lot more than any of us are using now) a known spring rate would be great!  Maybe Brit has figured it out and can share?  I'm pretty sure the truck companies aren't interested in working out these facts for trucks they may never sell.  When my Teton had 7K pin weight, the ride was fantastic!  And I was no where close to exercising my truck suspension.  But the newer DRV is really built for pickups and the light pin weights are not something any of us like.

Hi Rocky,

Brit's talk was interesting. From what I remember, it isn't  going to be a simple thing about making the trucks ride like a Cadillac. There is a need for custom parts. I don't know if Brit's presentation is on the ECR site. Carl might know. I won't be surprised the cost could be $$$$. There is also going to be a cost for labor. Brit had some ideas have to change things up. And there is prototype work work that needs to be done before it could really work.

Al

[Alie&Jim's Carrilite]

 Mike and Robin bought Brits old Volvo.  I had a chance to do a short ride in it and it rode "Different" than other 730's that I have driven or ridden in.  Brit had shocks built/valved for his known weights.  There are many "Band-Aids" many of us have tried.  Lowering tire pressure, Donvel Motion controls, different shocks- brand and rate, some have tried to add Ping tanks to increase volume to soften the ride.  Everything helps, but until you can add 30,000 to the hitch, the ride is what it is.

[Big5er]

4 hours ago, rpsinc said:

I viewed that trailer, and while the rigid hitch/pin box connection was a big reason for the failure, there was another factor.  The steel framing around the pin box seemed to me to have been built with roll formed steel rather than using structural shapes.  As well, it looked like it was 12-14 GA, and no welds were put on the bottom of each member.  The welds broke but mostly what I saw was the steel ripping from the stress and the light duty materials used around the pin box.  Yes, a cushioned hitch would have helped, but that isnt the answer for poor design.

This failure was certainly due to a number of factors.

Marcel, 
The trailer in question was a DRV which, if I am correct, uses a Lippert frame. Lippert has many issues, but there are a LOT of trailers using Lippert frames and to my knowledge pin boxes ripping out of the trailer is not a common one. 

The trailer is also a few (10+?) years old. Although I do not rack up the miles that most full timers do, my 2007 DRV didn't have issues like that and neither did the 2004 DRV parked next to me at the DRV rally the week before the HDT rally. I also saw that very trailer at the DRV rally and I attempted to talk him out of towing it anywhere. I was glad to hear that Henry (and others?) were more successful than I was. 

While I am not a huge Lippert fan, I would venture to say design was probably the least of the issues with the frame. As we know once you stress a piece of metal that is now the week spot. I'd bet it started with a weld issue that worked on stressing a spot (or two) location till it tore. I've watched the shop where I reside fix more than one and the common denominator seems to be heavy (big trailers or over loaded) trailers and rigid hitches. 

[Big5er]

3 minutes ago, Alie&Jim's Carrilite said:

 Mike and Robin bought Brits old Volvo.  I had a chance to do a short ride in it and it rode "Different" than other 730's that I have driven or ridden in.  Brit had shocks built/valved for his known weights.  There are many "Band-Aids" many of us have tried.  Lowering tire pressure, Donvel Motion controls, different shocks- brand and rate, some have tried to add Ping tanks to increase volume to soften the ride.  Everything helps, but until you can add 30,000 to the hitch, the ride is what it is.

When I was younger (ie, broke) I went to Grandma to borrow the down payment for a new truck while I awaited an insurance settlement. I drove the truck in question to Grandma's, pled my case and drove her to the bank in it. She commented that it was very similar to my father's truck. I explained that it was in fact similar but didn't have as smooth of a ride. I explained that dad had a Chevy, which rode like a car, and the truck I was buying was a Ford and rode a bit rougher, like a truck. My grandmother looked at me and said "But you're buying a truck, not a car. Isn't it supposed to ride like a truck?" You know, it's just kinda hard to argue with that sort of logic.

My Volvo is an HDT. It rides like an HDT. I don't see this as a problem. I don't see letting the trailer ride on an airbag, like the HDT does as a problem either.
I would never have argued with my Grandma and something tells me she would have told me if I expected a Cadillac ride, I shoulda bought a Cadillac. 

 

Miss you Grandma. 

[Lance A Lott]

2 hours ago, jenandjon said:

I understand what you are saying. Once you figure out what you are going to do and how you are going to do it, please share with the rest of us.  I for one am not willing to put smaller springs on my truck.  Yes I put a comfort ride hitch on for the camper but I am also putting a goose neck ball on. I want to be able to pull the 12 ton flat bed, 30 ft enclosed trailer, and 30 ft stock trailer (personal use not for the farm). 

One thing I did to improve the ride is I aired down my drive tires to 85psi. Right or wrong thats what I did. I didn't get a mile down the road and we could tell it rode real nice.

I use a cody cussion for my gooseneck trailers. It works relatively good. I also aired down the drives and that made a big difference. I also have donvales 

[beemergary]

22 hours ago, RJHILL said:

GEEEZ  what a bunch of nice people.  I was just trying to get a few members input on what I'm going to do to old MY Truck.  I have owned and operated this 84 359 Pete for thirty years and know every inch of it.  I'm now retired and would like to modify it for my wife and I can travel.  I don't even have facebook account or want one.  People like Big5er's childish comment does nothing but spread hate and BS drama .  Looks like I found the wrong site I don't have time for games.

My 84 359 Pete. I am 68 yrs. young and wife and I think it rides like a Cadilac. I do find a few screws loose in trailer but they were probably that way from factory.

[noteven]

My truck was ordered and built as a rv puller from new. The rear suspension has a driver controlled psi valve in line with the air level valve. You can manually adjust the suspension pressure down some from where the level valve sets it. It will go as low as 20 psi without much change in the ride height when bob tail. Ride is quite soft. As pin weight is increased you up psi until it eventually “meets” the level valve psi. I haven’t rode in the trailer yet but an observer watching the drive axle on a stupid rough road reports lots of rear axle movement soaking up the bumps.

 

[Parrformance]

6 hours ago, noteven said:

The rear suspension has a driver controlled psi valve in line with the air level valve.

I would like to see a photo or two of how this valve was plumbed in.

[HERO Maker]

I'm trying to get my head around how one valve doesn't override the other valve, or vise versa!

[beemergary]

51 minutes ago, HERO Maker said:

I'm trying to get my head around how one valve doesn't override the other valve, or vise versa!

A air pressure regulator after the leveling valve? Would need to see if you could maintain ride height with less than the 90-120#  Too damp and cold out today hook truck to my air compressor and turn down the psi and check it out. I know it doesn't take much psi to raise suspension after having no air in bags or truck.

[Darryl&Rita]

1 minute ago, beemergary said:

A air pressure regulator after the leveling valve? Would need to see if you could maintain ride height with less than the 90-120#  Too damp and cold out today hook truck to my air compressor and turn down the psi and check it out. I know it doesn't take much psi to raise suspension after having no air in bags or truck.

It doesn't work that way.

[rpsinc]

15 hours ago, Big5er said:

Marcel, 
The trailer in question was a DRV which, if I am correct, uses a Lippert frame. Lippert has many issues, but there are a LOT of trailers using Lippert frames and to my knowledge pin boxes ripping out of the trailer is not a common one. 

The trailer is also a few (10+?) years old. Although I do not rack up the miles that most full timers do, my 2007 DRV didn't have issues like that and neither did the 2004 DRV parked next to me at the DRV rally the week before the HDT rally. I also saw that very trailer at the DRV rally and I attempted to talk him out of towing it anywhere. I was glad to hear that Henry (and others?) were more successful than I was. 

While I am not a huge Lippert fan, I would venture to say design was probably the least of the issues with the frame. As we know once you stress a piece of metal that is now the week spot. I'd bet it started with a weld issue that worked on stressing a spot (or two) location till it tore. I've watched the shop where I reside fix more than one and the common denominator seems to be heavy (big trailers or over loaded) trailers and rigid hitches. 

Owning a contracting company, I hate to put blame on a company that builds things to someone elses specs(ie Lippert).  I agree that Lippert has a bad rep, and I just move forward to how they are building what they are building to a set of plans that they didnt produce.  Not sure who is at fault in their issues and of course there are many more trailers out there that dont have problems in their frames.  We have to our part to give those trailers the ride that best preserves the integrity of the whole rig.  That being said, rigid hitches and rigid pin boxes are NOT a good combination on the highways that we all use at 60+MPH.

I believe that the design for sure was a large contributing factor to that trailers failure, but so were the rigid connection with an MDT and many miles towing over bad roads.  Etc, etc etc etc.  

[Moresmoke]

The air pressure in the bag is a function of the bag diameter and the load on it.

The leveling valve controls the volume of air in the bag, not the pressure. As the load is increased, the leveling valve adds more molecules of air to the suspension to maintain your ride height. The pressure increases because the pressure in the bag must go up if the area stays the same to support the increased load.

For a given load, you cannot decrease the pressure in the bag as long as the diameter stays the same.  Letting air out will reduce the ride height, but will not lower the pressure until the stops hit.

The overall spring rate of an air suspension is controlled by the height of the air bag. The shorter the bag, the quicker the spring rate increases when the suspension is compressed. When you are looking at active suspension travel, we can ignore the height control valve as it can’t react fast enough to make a difference. If you have an air spring with 10 psi in it, and compress it to 50% of its normal height, you will have 20 psi in it. So if the theoretical air spring started at 10 inches tall, it will compress to 5 inches for a 5 inch travel. If we start with a 20 inch tall bag, it will compress to a 10 inch height under the same circumstances, giving us a travel of 10 inches. The taller bag will give you a “softer” ride.

We also have to remember that most suspensions are only partially air ride. One side of the axle is sitting on a solid mount, the other on the air spring.  A KW 4 bag suspension is full air ride.  If you look close, the bags are shorter than most others. If KW used tall bags like Volvo or Freightliner, their suspension would feel mushy under a heavy load.

Anybody that ever drove a Freightliner with their original short bag air leaf suspension would agree that it rode better than a Hendrickson walking beam, but not much.

The beauty of an air ride is that it self adjusts to the load that is on it.  The problem we run into with light loads is that the shock absorbers don’t self adjust, and the unsprung weight is very high.

 

[rickeieio]

3 hours ago, Moresmoke said:

 The problem we run into with light loads is that the shock absorbers don’t self adjust, and the unsprung weight is very high.

Finally, someone opened that door.  You're never going to get a really smooth ride with that much mass bouncing over the bumps.  I believe that was what Britt (bmzero) was working on.  Custom valved shocks will help, but they can only do so much.

[Moresmoke]

12 minutes ago, rickeieio said:

Finally, someone opened that door.  You're never going to get a really smooth ride with that much mass bouncing over the bumps.  I believe that was what Britt (bmzero) was working on.  Custom valved shocks will help, but they can only do so much.

Maybe we can get Rancho to come out with a 19000 series shock?

[Steve from SoCal]

Regarding shocks, I was looking at Bilstein shocks for motorhomes, they have no US heavy truck applications on their aftermarket site.      A truck with a single rear axle that hauls a trailer with 6K pin weight would be at about the laden weight of an empty trailer.     

My truck has perhaps the lightest rated suspension Flex-air at 17K and honestly bobtail with about 6K on the rear axle it is not harsh.   You guys with heavy tow bodies have an advantage but, the other thing that causes violent shaking is the extreme aft distance from the suspension to the hitch.      My truck with 10K+ on the back axle rides as well as any truck.    It still has some harsh bumps every once in a while due to road conditions.     I was in Michigan a few weeks ago and the roads there had me thinking I was on the Baja 1000!

Trucks that are tandem have a much higher rear suspension threshold to allow the air to actually work in the bags.     The compression is higher but, the real hit is rebound with little weight.   Drag racing shocks for front positions are 90/10 where 90% is compression and 10% rebound to allow the front end to lift.     An 80/20 shock inverted would perhaps be a good start for rear shocks on RV trucks.

 

Steve

[beemergary]

11 hours ago, Darryl&Rita said:

It doesn't work that way.

I didn't think so but thought it might be a good experiment. I thought I saw a presure gauges in line on a gas tanker lift axle before.

[lockmup68]

4 hours ago, Steve from SoCal said:

Regarding shocks, I was looking at Bilstein shocks for motorhomes, they have no US heavy truck applications on their aftermarket site.      A truck with a single rear axle that hauls a trailer with 6K pin weight would be at about the laden weight of an empty trailer.     

My truck has perhaps the lightest rated suspension Flex-air at 17K and honestly bobtail with about 6K on the rear axle it is not harsh.   You guys with heavy tow bodies have an advantage but, the other thing that causes violent shaking is the extreme aft distance from the suspension to the hitch.      My truck with 10K+ on the back axle rides as well as any truck.    It still has some harsh bumps every once in a while due to road conditions.     I was in Michigan a few weeks ago and the roads there had me thinking I was on the Baja 1000!

Trucks that are tandem have a much higher rear suspension threshold to allow the air to actually work in the bags.     The compression is higher but, the real hit is rebound with little weight.   Drag racing shocks for front positions are 90/10 where 90% is compression and 10% rebound to allow the front end to lift.     An 80/20 shock inverted would perhaps be a good start for rear shocks on RV trucks.

 

Steve

RoadKing will build them to your specific application and valving needs:

http://roadkingshocks.com/

 

[Steve from SoCal]

I don't really need them.     The suggestion was for trucks with tandem rears.    My Teton has about 5K on the pin, with that on my suspension the rear is right at 10K.     The new project I am working on will be at 10-11K and fully load the rear axle, it is rated at 17K.     Even bobtail as I mentioned the truck rides nicely.     As I said, flex air is considered the best riding suspension AKA AG380 for our KW fans.

 

Steve 

[noteven]

On 11/1/2018 at 5:51 AM, Parrformance said:

I would like to see a photo or two of how this valve was plumbed in.

 

The little fella has been doing some off pavement hobby truckin’ and has more to do today so a picture would not work until it sees a warsh bay. Today’s light tandem gooseneck highboy being pulled has the tire sidewalls for suspension. Axles are mounted on a 6ft spread walking beam, pivoting in Big Bushings on the frame.  Corners like it’s on rails. It’s I beam “pin box” won’t crack out. It’s “shackle bolts” are fine it has none.  The little Kenworth says “finally a sem eye trailer with it’s axles where they belong...all’s it needs is air brakes” ... 

My truck has 21K Hendrickson rear suspension. The control is like those used on lift axles to hold the air spring pressure at a set point for weight distribution. It does not have the “lift” circuit valve, just the psi control and oil filled gauge. 

My truck - Yes if you adjust the psi too low ride height begins to lower.  I use the “look between the tire and fender” method to set it.  Suspension psi gauge was not a factory option when the truck was built. One day I’ll get a roundtoit because I could use rear axle scales for some of the stuff I do with it. 

There is nothing wrong with articulating / suspension hitch coupling equipment. It is why pintle hitches and gooseneck with ball connections work so good in the pasture and on the 4x4 trail. 

Add some fore and aft “chucking” and vibration isolation and life is even better - see 4 link or “dog bones” or Mor/Ryde mentioned in hitch designs. There is a forum member here who has extensive knowledge around forces acting between tow vehicles and trailers. Search for fee nicks spelled properly. 

Tri axle belly dump gravel trailers use a simple fore and aft Big Pin on the upper 5th wheel for articulations to keep the tractor wheels on the ground off highway. It may work in rv land biggest drawback would be it would need another $25 of steel around it and do you have any idea what pins cost?!

I made most of the above ^ up. Do not attempt. 

 

 

[Lance A Lott]

The for and aft chucking probably does more damage to a 5ver with a ridged fifth wheel than any other single factor. On a pickup the trailer moves the truck when it hits a bump even a small one on a HDT not so much. Then the trailer frame must absorb that blow by flexing. With a semi trailer the pin box is often in line with the frame of the trailer but on a 5er it is offset this forces the frame to flex usually between the pin box and the reinforced corner where the frame drops down to the body of the trailer. A fifth wheel hitch with play will help with this.

[Parrformance]

So Lance A Lot, would you then say that a TT is more like a semi trailer as the frame is inline with the hitch?

I have purchased a suspension hitch for the HDT, in hopes of preserving the trailer, and keeping things in the cabinets more or less in a similar position they started in when leaving my home in sunny Central Florida.  

The suspension hitch should reduce some of the fore and aft shock of the trailer due to the arc of travel, but more so it will provide a float of the tongue in reference to the rigid hitch on the HDT.  Am I expecting to much from this hitch? 

https://www.amazon.com/Torsion-Suspension-Receiver-Towing-Pintle/dp/B01N7AXNFI

 

[Moresmoke]

27 minutes ago, Parrformance said:

So Lance A Lot, would you then say that a TT is more like a semi trailer as the frame is inline with the hitch?

I have purchased a suspension hitch for the HDT, in hopes of preserving the trailer, and keeping things in the cabinets more or less in a similar position they started in when leaving my home in sunny Central Florida.  

The suspension hitch should reduce some of the fore and aft shock of the trailer due to the arc of travel, but more so it will provide a float of the tongue in reference to the rigid hitch on the HDT.  Am I expecting to much from this hitch? 

https://www.amazon.com/Torsion-Suspension-Receiver-Towing-Pintle/dp/B01N7AXNFI

 

That hitch or one of the airbag bumper hitches should do fine to remove the “jarring”.  The highest stress point on your TT hitch will be right under the front wall. While I am sure the forces are greater on an HDT than on the back of a one tone, they probably aren’t any worse than the guy that has the weight distribution bars cranked right up to lift the back of the Elcamino off the pavement.

Myself, I opted to just run a rigid ball mount. But then, pulling the TT is not my primary reason for having the HDT.

[Lance A Lott]

 

1 hour ago, Parrformance said:

So Lance A Lot, would you then say that a TT is more like a semi trailer as the frame is inline with the hitch?

I have purchased a suspension hitch for the HDT, in hopes of preserving the trailer, and keeping things in the cabinets more or less in a similar position they started in when leaving my home in sunny Central Florida.  

The suspension hitch should reduce some of the fore and aft shock of the trailer due to the arc of travel, but more so it will provide a float of the tongue in reference to the rigid hitch on the HDT.  Am I expecting to much from this hitch? 

https://www.amazon.com/Torsion-Suspension-Receiver-Towing-Pintle/dp/B01N7AXNFI

 

I will either be getting this one or a shocker airbag hitch when I start to use our TT again. We have only used the gooseneck living quarters horse trailer for the last 2 years. I have talked to several people with the hitch you picture and they love them. We have really ruff roads in Vermont and they love the improvement.

 If you bend a paperclip to look like the frame of your trailer including the hitch and pull on the back bumper and the hitch you will see the wire flex. pull where the floor of the bedroom would be and see where the wire flexes. hook it on your fingernail and on the skin of your finger and you can see the difference cushioning makes.I have seen pictures of failed 5ver frames and they look very week compared to the frame on a gooseneck trailer. 

we can not eliminate these forces but we can lesson there effect. One other thing i have seen with HDT's is that some drivers go faster than they did in a one ton as they dont feel the bumps like they used too. I have caught my self doing it. Another contributing factor is when we replace undersized tires with real tires they don't flex like the lighter tires did.

[alan0043]

Hi Everyone,

I have an idea that I want you guys to let me know what you think. Pro or con. I don't want this idea to get anyone hurt or killed. From what I have been reading some people would like to have the truck ride a little softer. Some of the talk was to change the amount of air in the air bags. With less air in the bags the truck could ride softer. But if this is done the correct height will not be right. Here is my idea. I am probably not the first one to think of this. Here goes. How about making a spacer for the air bag. Take the air bag loose from the truck. The spacer could be 1" to 2" thick. The spacer is attached to the truck where the air bag was attached at. Then attach the air bag to the spacer. My thought is that you won't need as much air in the air bag to get the correct ride height because you have already raised the truck 1" to 2". The air bag should be softer with less air but the ride height should be correct.

What do you guys think, pro or con
Al