5th. wheel surging, bucking, bouncing

[Old-Biscuit]

Those Rubber Compression Bumpers attach to upper section of pin box using those 2 silver bolts ----in between the rods

You need 2 new Bumpers....and possibly a new 'Shear Spring' (based on weight)----the shear spring is attached to king pin late and to upper section. Provides that cushioning affect

Bumpers/Shear Spring ,,,,,,,damaged----could be the cause of chucking/bucking/bouncing
OR damaged due to all that chucking, bucking, bouncing


Is 5th wheel being towed LEVEL or NOSE High?
What is the WET Pin Weight??
**Have you weighed truck/trailer and then just truck to find ACTUAL weight numbers????

MorRyde
574.293.1581


Pin Box Manual
https://www.morryde.com/wp-content/u...ers-Manual.pdf

[bighamstoy]

Any opinions on the Flexair pin box? It has an air bag and shock built into it. Looks like (from the video anyway) it would eliminate “chucking”. If it did it’s worth the $1300+. Gonna try leveling and moving the pin centerline forward first. I put PullRite adapter on so it moved the original pin location just behind the axel center line. If I switch it the other way it will move it about 2 inches forward of truck axel. Oh, and attach the rubber bumpers.

[tuffr2]

I think the Flexair Pin Box will eliminate chucking. I had a Morryde pin box and I had zero chucking for the 6 years I owned the 5th wheel. I towed approx. 25,000 miles.

[brialin]

I had the same trouble with my 35' montana with the morryde. The trip home from the dealer was terrible. I replaced it with the trailair pin box and have had no trouble since. I had a trailair on a previous 5th wheel and it made the ride a whole lot smoother on rough roads. You can watch the front shock on the hitch move 1-2" going down the road. The air bag is taking a lot of the shock from being transferred to the pickup.

[bighamstoy]

Ok another question. I turned the Pullrite adapter so the trailer is now about 6 inches further over the truck bed. I lowered the hitch to it's lowest setting. Tires are at 50 lbs. While all this helped, it's still got the bucking/surging issue. The trailer still looks nose high, about 8" truck bed rail clearance. Here's my question. Would it be advisable to drill another hole in hitch adjustment head to lower it about 1 more inch? There is room to do that on adjustment and it will lower trailer height another inch or so. Or will one or so not make much difference? Attachments below. Inquiring minds want to know!

[tuffr2]

Do you ever not have bucking/surging or is this all the time. With a Morryde pin box your experience should be 98% smooth.

My 5th wheel would be smooth 98% of the time with the Morryde pin box. On a very rare occasion I would have bucking but I attributed that bucking to the joints in the highway and an uneven highway joints matching my tires at an odd frequency to cause bucking.

My 5th wheel had a heavy pin as I had the front loaded with all kinds of stuff. Tools, chairs, extra 50amp cable and lots more

Just by chance, maybe you do not have enough pin weight?

[Theunz]

Pay attention to what Old-Biscuit says in post 15
No fancy hitch will fix a damaged pin box. FIX YOUR PIN BOX! If you aren’t happy, then try other remedies.

[The Guthries]

Originally Posted by mtofell

My airbags help this A LOT. Basically, the same idea as good shocks on the truck. The bags stiffen up the hinge between the truck and fiver and really cut down on the rhythmic bouncing that can develop over uneven sections of road.

I honestly don't need the bags for sag but really appreciate the overall ride improvement when the 5th is behind me.

This! It solved my forward/backwards “rocking” feeling.

[CecilD]

As I mentioned before, your trailer is pushing forward at the same time it is pushing down. Hardening the rear suspension with air bags will help as it will limit the down forces and at the same time limiting pushing forces. The problem is, all those forces will still be there plus the added forces from the truck that the hardened suspension can't mitigate are shooting into the trailer. Every solid hitch is very efficient at transmitting the energy. Those forces are absorbed by frame flex on your trailer.

If you are serious about a comfortable tow get a Trailer Saver TS3 to fit your ISR rails. This is what I did after doing the Bilsteins and air bags thing with no relief. Tow went from bad to pleasurable. Only your wallet won't be happy with the hitch.

The high hinge design of the TS3 causes the hitch head to retract when it is being depressed alleviating chucking forces. The energy created by the trailer is converted to heat by compression and radiated into the atmosphere through the bags and shocks. The trailer is still doing its thing, you just won't feel it in the truck. Your trailer frame is not absorbing energy, instead enjoying a soft touch. Braking traction will improve as the trailer is pushing down during stops further loading the rear tires. They named them Trailer Savers for a reason.

[bigchick]

i had to replace those rubber bumpers on our 2015 5th wheel. they can be replaced without taking the pin box apart if you can use a compact socket wrench. i think they were something like $25. they keep the movable metal place of the pin box assy that anchors the king pin from contacting the fixed metal shell of the pin box that is connected to the trailer frame.

the rubber shear spring that sits between the two metal pieces, (the fixed box and the movable plate) can go bad and need to be replaced. morryde told me they can last 10 years or so. but it may be that yours is deteriorated and needs to be replaced. it is this rubber spring that dampens the movement and prevents the chucking. the replacement spring is a little over $200. it can be replaced buy the owner. lots of videos on either you tube or morryde web site.

our 5th wheel is 16,000 lbs and we use a curt Q20 hitch with the factory pucks. the chucking is minimal.

[bighamstoy]

Just trying the cheapest possible solutions before spending lots of $$$$. I had problems with my last trailer (a tow behind) and spent lots of money on shocks for trailer, truck, new stabilizer bars, etc, and none of it worked. Come to find out my truck ball joints were worn out and needed replaced. Next step is new shear spring and bumpers. If I hadn't recently retired I'd just throw money at it...

[bighamstoy]

Originally Posted by bigchick

i had to replace those rubber bumpers on our 2015 5th wheel. they can be replaced without taking the pin box apart if you can use a compact socket wrench. i think they were something like $25. they keep the movable metal place of the pin box assy that anchors the king pin from contacting the fixed metal shell of the pin box that is connected to the trailer frame.

the rubber shear spring that sits between the two metal pieces, (the fixed box and the movable plate) can go bad and need to be replaced. morryde told me they can last 10 years or so. but it may be that yours is deteriorated and needs to be replaced. it is this rubber spring that dampens the movement and prevents the chucking. the replacement spring is a little over $200. it can be replaced buy the owner. lots of videos on either you tube or morryde web site.

our 5th wheel is 16,000 lbs and we use a curt Q20 hitch with the factory pucks. the chucking is minimal.

Did you contact Morride directly for parts? I can be stubborn looking for things on the internet...and I hate talking on the phone (bad hearing). I emailed Morride finally to get parts help'

[bigchick]

yes, i contacted morryde and they were very helpful. also look online at their pin box manual. there were some good exploded parts diagrams and some videos. the biggest issue is that you might need two people to disassemble / assemble the pin box while it is mounted on the trailer. one to work the bolts and the other to hold the pin pieces in place until it is fully disassembled.

that rubber spring in the pin box serves to dampen any movements and acts like a shock absorber. the upper and lower plates of the pin box can slide in relationship to each other on the two steel rods holding them together. the bumpers prevent the two steel plates from coming in contact with each other. i can't say if this is the best pin box on the market but it works for us.