Why is my triple axle 5th wheel now swaying??? Fuzion 420 triple axle

[twvette]

Hello everyone, on my last trip I was white knuckled and felt like pulling a bumper pull with no sway control. It was over 100 miles each way and multiple highways/roads. Have never had this happen in the 3+ years owned this rig (or my other triple's) as normally its an anchor and even high cross winds would be straight as an arrow. No changes in setup, what was hauling, tire pressure, etc. Even noticed it on uphill pulls. Crawled up underneath and shackles, leafs, leaf mounts, tires, etc. seem fine. Anything known to cause this? Maybe something worn out? I do have the MorRyde CRE3000 and their Pin box which all have rubber components. Using the Andersen Ultimate 5th wheel hitch and don't see anything that seems like abnormal wear to me. Maybe bad bearings? Stumped ....

[flybouy]

I'd jack it up a wheel at a time and inspect the bearings and brakes. Maybe a broken brake magnet or component dragginging and causing the trailer to pull to one side? Have you taken a straight edge across all the wheels on each side to check for axle shift? Just a guess on my part.

[JRTJH]

What tires are on your trailer and on your truck? Is it possible that the trailer tires are "at their rated load limit and may have a tread separation on one or more? or possibly the truck tires are contributing to the sway?

You described it as "sway" could it be better described as "squirm" or "squirrely movement" ??

[twvette]

Almost forgot how easy it was to get trailer off ground since have hydraulic jacks. The middle axle hangs a little lower than front and rear so had to use my Andersen blocks/buckets to get the middle axle tires off the ground.

I did notice the middle axle kinda dropped suddenly when lifting so it might have been a little bound up when lifting if this is a sign of anything.

Did the straight edge check. Only have a 4ft'er and seems the middle axle is maybe off an 1/8in at the top (camber) on both sides from both the front and rear axles ... perhaps this is due to it drooping lower when off the ground but little strange as bottom of this tire is in line it seems.

Checked each wheel to see if could move side to side to check bearings. One of my rears has a very slight amount of play but all others rock solid.

I did notice all my tires have a bit of a ledge on both the inner and outer edges maybe 3/4in inch in fromt he edge. Supposedly this is a sign of under inflation but I always keep mine at pressure and check regularly. Maybe its my tires are just now that much "narrower" and perhaps it is "rolling" onto those edges now as it gets wider(?). Curious if any other signs of issues with this tire wear signature.

I have the original Sailun 637's 110 PSI.

I have Nitto Ridge Grapplers rated at 3650 each. Checked all of them for inner tread separation signs/bubbles/deformation and good.

I would say it is a lot of squirm with some sway so having to correct with steering wheel. Even wife noticed the trailer swaying when following me in her car this trip which she also thought was weird as often follows me. Enough sway too that could tell on occasion cars passing were a little hesitant and moving to far side of their lane in some cases but never really crossed into into their side.

[bobbecky]

Something that hasn't been mentioned that you might check, and that is the U-bolt nut torques on U-bolts that connect the axles to the springs. These are commonly overlooked, and many of us on the Montana Owners Forum have discovered that the nuts are usually loose from the factory because the nuts are torqued by Dexter, but once the weight of the trailer flattens the springs, the nut are loose and Keystone/Montana does not re-torque these nuts, and this could cause a bit of looseness in ride.
https://www.dexteraxle.com/docs/defa...s.pdf?sfvrsn=2

[twvette]

Thanks, will check the ubolts. I did look at them and did'nt see any sings of rubbing etc to indicate they might be loose but will put a wrench on them.

I did find the two set screws in the Andersen hitch were loose. That does give the hitch a little lateral movement so that might translate to a lot of sway in the rear perhaps. Not truly sure this is the cause but maybe in combination with the condition of tires, etc.

I am suspicious of the MorRyde rubber bushing pin box now too. I think it is for forward and backwards movement primarily, but I can put my hands across two diagonal corners and rotate/move it like 1/4 inch somewhat easily. I cant move it at all front to back. Maybe a rubber bushing is worn out, etc.? The rubber stuff has me more worried than most perhaps being I am in Phoenix, AZ. If someone has a new one and can see if it does that would be good to know or I might stop in at a RV dealer to check one.

[flybouy]

One question I didn't see asked. What's "changed" from the last tow to the tow "previous" and what was the time in-between? Without the trailer does the truck track straight? Let go of the wheel driving straight and level no pulling to one side or "wandering" ? A little sloppiness in the truck's steering can set up a situation where the truck wanders off to one side then you correct (or over correct) and then everything goes the other direction and it repeats.

[travelin texans]

Originally Posted by twvette

Almost forgot how easy it was to get trailer off ground since have hydraulic jacks. The middle axle hangs a little lower than front and rear so had to use my Andersen blocks/buckets to get the middle axle tires off the ground.

I did notice the middle axle kinda dropped suddenly when lifting so it might have been a little bound up when lifting if this is a sign of anything.

Did the straight edge check. Only have a 4ft'er and seems the middle axle is maybe off an 1/8in at the top (camber) on both sides from both the front and rear axles ... perhaps this is due to it drooping lower when off the ground but little strange as bottom of this tire is in line it seems.

Checked each wheel to see if could move side to side to check bearings. One of my rears has a very slight amount of play but all others rock solid.

I did notice all my tires have a bit of a ledge on both the inner and outer edges maybe 3/4in inch in fromt he edge. Supposedly this is a sign of under inflation but I always keep mine at pressure and check regularly. Maybe its my tires are just now that much "narrower" and perhaps it is "rolling" onto those edges now as it gets wider(?). Curious if any other signs of issues with this tire wear signature.

I have the original Sailun 637's 110 PSI.

I have Nitto Ridge Grapplers rated at 3650 each. Checked all of them for inner tread separation signs/bubbles/deformation and good.

I would say it is a lot of squirm with some sway so having to correct with steering wheel. Even wife noticed the trailer swaying when following me in her car this trip which she also thought was weird as often follows me. Enough sway too that could tell on occasion cars passing were a little hesitant and moving to far side of their lane in some cases but never really crossed into into their side.

The wear on the inner & outer edges of the tires is normal especially on a triple axle trailer, if you've ever watched the tires when backing into a tight spot watching them scrub you would think they were about to roll off the rims, every turn this happens to some degree.

[Frank G]

2016 Fuzion Chrome 420

Dry 15,055 lb
Payload 3,905 lb
GVWR 19,000 lb
Hitch 3,775 lb

On a SRW 3500 ???

[gearhead]

Run a string down the edges of the tires.
The Morryde pinbox is a one piece rubber shear spring. It's about 1.5" thick and about 7" x 10" and is basically a 1 piece thing, unless it has failed. How close are you to the max rated GVW for it? It's pretty simple to remove and inspect. Morryde has a you tube on it. You will likely need help to manipulate it. You will need a torque wrench up to 100 ft.lbs. and blue Loctite. Grease in the socket to keep the nuts from falling off in the 4 holes on top, then switch to a deep socket after starting the nuts. A new shear spring is about $150 from Morryde. I think a #5 spring is good to 18,000GVW and a #6 is above 18,000.
I just swapped mine out thinking it had failed and was causing my slamming at start and stops. No, my ignorant self had the foot pads of my PullRite hitch reversed.
Senior Machinery Specialist my foot. LOL

[notanlines]

Originally Posted by Frank G

2016 Fuzion Chrome 420

Dry 15,055 lb
Payload 3,905 lb
GVWR 19,000 lb
Hitch 3,775 lb

On a SRW 3500 ???

Frank, we see you poking that stick through the fence at the barking dog...

[AbHDToyHauler]

With trailer in air spin each tire and look down front face of tire to look for runout(bulges in sidewall). Do same on inside of tires. Do this to the truck too. I had a Cadillac once that started to suddenly wobble all over the place. There was a bulge in sidewall (inside of tire) and when rolling down road it was like a clown car. Took my friend behind me watching to see what was wrong.
Hope this may help. Good luck with sorting out your problem!

[rhagfo]

Did you by chance put new tires on your TV?

[twvette]

Thanks again to all the useful replies on the topic. I see caught a fish too.

The string is good idea to run the entire wheel edges in one so will try that but think its good from the straight edge already did.

Will look into the MorRyde pin box and watch the video. Just seems a bit strange to me can twist it.

Not seeing any buldging tires.

I did get two new tires on the truck. One got a screw near sidewall so they replaced it with the certs I bought and pushed them for a second one as I am down to just below 50% tread and did not want uneven tires on same axle. So did end up with two new ones on the rear for this trip and that is the only change from last trip besides different roads. The truck did feel a little loose steering out of the parking lot of the tire shop but that seems to have went away quick. So I do have two ~50% tires on front and two 100% on rear. Will check out the truck/tires more.

[gearhead]

Maybe talk to this guy:

Ryan Holmes
Aftermarket Sales

MORryde International, Inc.
1966 Sterling Avenue
Elkhart, Indiana 46516
O: (574) 293-1581 ext. 1212

[Frank G]

Originally Posted by twvette

Thanks again to all the useful replies on the topic. I see caught a fish too.

The string is good idea to run the entire wheel edges in one so will try that but think its good from the straight edge already did.

Will look into the MorRyde pin box and watch the video. Just seems a bit strange to me can twist it.

Not seeing any buldging tires.

I did get two new tires on the truck. One got a screw near sidewall so they replaced it with the certs I bought and pushed them for a second one as I am down to just below 50% tread and did not want uneven tires on same axle. So did end up with two new ones on the rear for this trip and that is the only change from last trip besides different roads. The truck did feel a little loose steering out of the parking lot of the tire shop but that seems to have went away quick. So I do have two ~50% tires on front and two 100% on rear. Will check out the truck/tires more.

Have you checked the lug nuts since the tire work? Have you checked the trucks suspension?

The Fish

[JRTJH]

It's a bit "labor intensive" but you might consider rotating truck tires, front to back, that way the "known good tires" are on the rear and the new tires are on the front... It may not make a "hill of beans" difference, but it might also "cure the wobble"... Before spending big bucks on things like alignments, rebalancing tires on the trailer, shocks or a new fifth wheel hitch, I'd want to at least make sure it's not those new tires "squirming" on me.

[flybouy]

Agree with above. Now that you know the "when" it happened time to figure out the "why". I'd recommend checking the tires for the same size, load rating, and air pressure as well as lug torque. If everything is good then swap (or have them done) front to back.

[gearhead]

Originally Posted by notanlines

Frank, we see you poking that stick through the fence at the barking dog...

Eh the dog got bored and fell asleep. Let sleeping dogs lie?
I'm thinking it is not a match made in heaven.

[bobbecky]

I think those two new tires are probably the problem. Are they an aggressive tread compared to a highway tread? If that is the case, you might solve your problem by installing new tires on the front too.