Smoothing out the ride...

kb9cfv · 06-25-2012, 04:47 PM

Good Day everyone. New to the forum. DW and I recently picked up a new Salem 271BHXL. This was an upgrade from our little Bantum. It is also the first real trailer I have had that needed WD. With out turning this into another WD thread I was wondering what options I may have to dampen out the porpoising effect felt at random. The TV is a 05 Ford SCrew F150 with 3.73 GR. The trailer has a dry weight of about 5465 and a tongue of around 640. The truck is book rated at 9900/990 with WD. I currently have the WD set to restore the Front axle to within 1/4 of unload weight. The truck rides well I think.
I plan on getting real weights next week at the scale.
I have pulled 300 miles so far trying different settings on the WD. Towed really well until the dreaded concrete interstate and I had violent porpoising for about 5 miles. I put another link on the chain and that helped a bit, but made the trailer more susceptible to sway. (A condition I think from too much pull from one of the bars causing the nose to pull slightly) and very stiff. Not a good feeling at all. I put everything back to before it it was great untill another stretch of bad highway.

So my question is not so much about WD setup, I will really dial it in once I have real weights, But will bags or springs help dampen the up/down effect caused by our great roadways?
Thanks for reading..

TURBS · 06-25-2012, 05:31 PM

Quote:

Originally Posted by kb9cfv

Good Day everyone. New to the forum. DW and I recently picked up a new Salem 271BHXL. This was an upgrade from our little Bantum. It is also the first real trailer I have had that needed WD. With out turning this into another WD thread I was wondering what options I may have to dampen out the porpoising effect felt at random. The TV is a 05 Ford SCrew F150 with 3.73 GR. The trailer has a dry weight of about 5465 and a tongue of around 640. The truck is book rated at 9900/990 with WD. I currently have the WD set to restore the Front axle to within 1/4 of unload weight. The truck rides well I think.
I plan on getting real weights next week at the scale.
I have pulled 300 miles so far trying different settings on the WD. Towed really well until the dreaded concrete interstate and I had violent porpoising for about 5 miles. I put another link on the chain and that helped a bit, but made the trailer more susceptible to sway. (A condition I think from too much pull from one of the bars causing the nose to pull slightly) and very stiff. Not a good feeling at all. I put everything back to before it it was great untill another stretch of bad highway.

So my question is not so much about WD setup, I will really dial it in once I have real weights, But will bags or springs help dampen the up/down effect caused by our great roadways?
Thanks for reading..

I just installed air bags on my 3/4 ton pulling a fifth wheel which was also porposing.
Just drove 38 miles and was night and day.
I recommend air bags as your first upgrade. You won't be disappointed!

caper · 06-25-2012, 06:28 PM

What are the size of bars on the WDH? If they are 800# then you might want to go to 1000#.

transamz9 · 06-25-2012, 07:13 PM

I would try these first. These will make all the difference in the world.

Bilstein Truck Shocks - Shockwarehouse.com

kb9cfv · 07-09-2012, 04:08 PM

Hello again, just to update this thread. In the last few weeks I have replaced the rear shocks with the Bil steins. That made a dramatic improvement on the ride but still had the shakes from time to time on the interstate. As stated before I tried a variety of hitch setups to better distribute the rear weight to see if that would help to. Turns out that out the door at the dealership, they had me setup overloaded on the rear axle. I went back and mentioned it and they found the ball height and everything mismeasured. I made a total of 4 trips to the scales to try different setups and as it stands now, My front end is 60 pounds shy of unloaded weight and the back end is carting about 900 pounds with fuel and kids. However it feels springy. I know the WD is probably causing a lot of that, but I remember my smaller trail lite did the same but not as bad given the lighter tonge weight. The entire rig weighs in at 12250. trailer dry weighed in at 5440. Truck sits about 6000. I am running 750lp bars. Will stronger ones help or....
What do you think my options are at this point. The trailer is nose heavy at around 900 with the WD installed.

Thanks for the input.

lindy · 07-09-2012, 05:37 PM

You need to shift more weight to the front axle! A good starting point is to level the trl, measure the tongue height and set the ball at the same, and measure the trl height when level front and rear at a same body line, also measure trk body height front and rear unhooked. Hook up and adj WD bars till trl is level again, then check trk body height, body should be lowered about the same BOTH front and rear, rear maybe slightly lower. Goal is to get trk and trl level and the same line with weight shifted to front and rear.

lindy · 07-09-2012, 05:42 PM

Also forgot to add that SOME concrete highways will porpoise due to the way they are layed. It's a ground effect bounce that sets up based on the distance between the slabs of concrete and the wheel base of the trk and then the trl wheels. In this case there's nothing you can do to stop it short of redoing the road. We have a stretch of I-90 thru Buffalo NY that's like that since the day they poured the concrete. The state knows there's an issue but won't address it due to costs of grinding the surface

caper · 07-09-2012, 06:55 PM

If I am reading your statement right you have a 900# tonge weight. If that is the case then the 750# bars are too light.

jwuertz · 07-09-2012, 07:32 PM

I have noticed that with the WD hitch the bumps in the road are a bit more noticable. I used to have a Keystone hybred and did not use a WD hitch and now I have a Rockwood 2304S which is heavier and needs the hitch. Pulling the hybred was not quite as bouncy as is the the Rockwood with the WD hitch. But it all depends on the road also.

kb9cfv · 07-11-2012, 06:47 PM

Caper, That's what i thought too. This morning I swapped out for a 1000 pound bar and reweighed the setup. I'm at 880 now. It firmed up the ride a bit, but that is what i am hoping. I suspected I was overloading the 750 bars and that was adding spring when I found the bad patches of road. I won't know until I take a trip so here's hoping. The only thing I'm really worried about now are the tires. (trail express) I'm keeping my eye on them. (got a tpms first thing before we bought the trailer.)

We are planning a run out to DC and NC next month so i hope to dial this in before then. Ideally i'd like to put another 100 pounds to the front axle. I'm about 40 pounds shy of unloaded weight by the scale. The toung still seems a touch heavy to me.

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