Holy Porposing Batman! Your Experienced Needed

I just returned from picking up my Sundance 3300 RLB – a good thousand mile drive to break in the tow vehicle and the Sundance. Many cracks in the road (especially on concrete highways) caused the truck to propose/chuck/rock. I never felt out of control, but it is noticeable.

I have rear Timbrens on the stock Dodge 2500 Megacab 4x4. With no load they have about a 3/4 to 1” gap to the axle. With the 5th wheel attached, the Timbrens compress about 1/2 “ – the 5th wheel sits just right. The hitch is a B&W Companion. I weighed the rig at a certified scale and everything is within the specs, with one oddity:

Truck front axle: 4780 lbs (5200 lbs is max rating)
Truck rear axle: 5560 lbs (6010 lbs is max rating)
Sundance gross axle weight: 8240lb

The oddity:
Sundance front axle: 5360 lbs
Sundance rear axle: 2880 lbs

The trailer was empty, so it should be close to its spec dry weight of 9850 lbs. I don’t understand why the big difference in the axle weights – is it because we have not loaded up stuff in the back yet? Tires on truck and trailer were all at the rated pressures.

Any ideas for limiting the proposing? Will a packed trailer help? Could Timbrens on the front axle help? I like to avoid adding airbags due to cost and I don’t know if they would help a lot.

I appreciate your ideas.

And yes, I love my Heartland (but we still need to put it to real use)!

Either the scale is wrong or your trailer is way low in the front putting all the weight on the front ???????? Jon

You have the rear axle weight when hitched up, but do you know the weight of the truck rear axel when not hitched? Actual pin weight would be helpful. And I'm with Jon on whether or not your Sundance is level or a bad scale reading.

Peace
Dave

I agree with Jon and Dave. 2500# is a big weight difference. Unless there is a problem with the suspension, your coach is sitting nose down. That will cause a bad case of "porposing". I suggest that you park the rig on level ground and look again. Put a 4' level on the floor of the coach and see what it shows. I assume that all the tanks are empty. You just might have to bite the bullet and install air bags. Good luck with this. Bob

I'm glad I'm not the only one the axle weights didn't make any sense to. The 5th wheel was sitting pretty level. I had the wheels straddling the sections of the scale, and it could be that the back wheels were also touching the front secton of the scale. I'll check it again next time we are out.

Forgetting about that -- any other suggestions for reducing porpoising?

Oops -- just saw I spelled that wrong in my initial post -- must be my spell checker

1st you have to get the coach and TV level. Next is invest in a good cushioning pin box. I like the Mor/Ryde pin box. It takes the chucking out of the ride. Just for grins and giggles, how are the shocks on your TV? Worn or weak shocks can give you a bad ride. Such as bouncing to much after a bump.

I have never trusted the weight scale for RV's as they are so light. I once had a weight done on a previous trailer and the weights were so far off that I avoid them completely. I trust the manufacturers weights and I know the weight of my Stuff in the unit and add the water and Propane. My Ford rides just right, with hardly any load on the helpers, and the ride of the trailer is smooth enough that everything do not move at all in the unit. My springs on the truck take the bumps of the road perfectly while the trailer keeps the box from moving. To me its the perfect ride like driving a Caddy. I always adjust the truck springs to the pin weight so as to ride properly without sway or jolts. This BC is far from having the pin load of the previous 5th wheel, so I am not concerned, because I hauled the other trailer 9 years with a 1998, K2500 GM with standard springs and original shocks. But the GM could handle more load so I added one more ply to the Ford F250 SD (3500lbs compared to 2800lbs).

In the US any scale that is used for commerce such as Grain Elevators or Truck Stops is certified. You can bet it is within 20 pounds of the actual weight. They are checked and re-checked to maintain the certification. Run across one and you can verify that you weight what you think you do. Many of the elevators wont charge you and you can check your individual axles which is nice to know. Sounds like you are getting along towing just fine. We like our F250 super duty for towing very well with stock springs and air bags.

Fifth Airborne hitch will almost completely eliminate chucking. I am sure others will as well. I like the design better than some of the others. To get proper weight on the axles it is important to get out and look and make sure the axles are stopped with one on the scale and the other on the steel/cement. Everyone should have at least 5 actual weights. 1. Total weight TV/Coach 2. TV Front axle hitched 3. TV rear axle hitched 4. Front Coach Axle 5. Rear Coach Axle (one more if you have 3 axles). Really nice to know the difference from side to side as well. Most of the 3 slide Coachs and large two slides on the Off curb side are quite a bit heavier on that side.

Make sure your hitch is properly installed. After towing for nearly a year and surfing after every bump, at a Heartland Rally I was asked if I had problems towing with my 1 Ton Dodge. Long Story Short, the hitch was three inches to the rear of where it should have been, instead of 3 inches in front of the rear axle. Re-install made all the difference in the world. Tows like a dream now.

I had mine forward of the rear wheels but I had no room at the back of the tailgate when opened, I cannot hitch with the tail gate open because if the truck is a bit sideways the gate would hit the trailer. So I am back at the 1" in front of the axle. These trailers are close for long wheelbase trucks.

I thought you were looking for advice on how to propose to your sweetheart...I think the word you want is porpoise!

propose, porpose.. I am still lost where is this term coming from

2010augusta said:

propose, porpose.. I am still lost where is this term coming from

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Porposing is when the rig bucks either back and forth laterally or up and down which usually translates to a forward/back motion in the tow vehicle. Usually caused by a significant problem with weight distribution.

so really porpoise.

Ah, like the up and down motion of a dolphin or porpoise

2010augusta said:

Ah, like the up and down motion of a dolphin or porpoise

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Roger that gold leader....

Charlie Harris said:

Make sure your hitch is properly installed. After towing for nearly a year and surfing after every bump, at a Heartland Rally I was asked if I had problems towing with my 1 Ton Dodge. Long Story Short, the hitch was three inches to the rear of where it should have been, instead of 3 inches in front of the rear axle. Re-install made all the difference in the world. Tows like a dream now.

Click to expand...

Hi Charlie -- I was wondering about that also and will check it. However, I am using a B&W Companion and I am pretty sure it was installed with the correct kit for my Dodge Ram -- I think it can only go one place.

Thanks!

biggziff said:

I thought you were looking for advice on how to propose to your sweetheart...I think the word you want is porpoise!

Click to expand...

Yes, I caught that too -- I think my spell checker got the better of me. And forcefully, this forum tool will not allow me to edit the title of a message thread. Oh well -- spelling has never been a strength.

Further, my sweetheart and I are working on 14 wonderful years of marriage -- I am very glad I proposed

2010augusta said:

Ah, like the up and down motion of a dolphin or porpoise

Click to expand...

You got it! It would help if I spelled it correctly.

I don't see anything wrong with the spelling.

Jim M