Trailer Shake - I'm out of ideas

Natesms

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I need some help trying to figure out what to do next to try and solve this shake in the trailer. I have a single axle trailer with surge brakes, 19.5' foot boat. At 63 MPH a shake starts and it gets extremely heavy at 70, then smooths out again towards 80 (I basically have to drive at 65mph or slower at all times). I have tried everything I can think of to get rid of the shake. Everything I have done has not changed the behavior at all.

What I have done, in order:
* Tires Balanced
* Paid to have bearings gone through, at the time they said bearings were good and just repacked them (2 years ago, I have little faith in the place that did it).
* Tires re-balanced (threw a weight)
* Personally went through the bearings. Drivers side had a little play but was in good shape. Tightened up and no play when I was done and rolled smooth and quite. Passenger side was in bad shape. Replaced bearings and races. (today)
* Replaced the drum brake spring on passenger side (was broken, shoes looked okay)
* Borrowed 2 brand new tires (still had the stickers on them) and put them on, no change.


I'm out of ideas. I can't say for sure if the surge brakes work but I know they aren't dragging when its up on the jack stands.

Anyone have any suggestions on what to do next?
 

GA_Boater

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You didn't mention tongue weight, usually the leading cause of the tail wagging the dog. A new rig to you?
 

Natesms

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I should have mentioned that, no wagging at all. She tows straight as can be. Even when it shaking it doesn't walk around on me.

This is my 3rd season with the boat and has done it since I bought it.
 

kjsAZ

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shaking is less an indication of a tongue weight issue especially if it goes away again at higher speeds. (You are aware that your tires are only approved/rated up to 65mph???)
You most likely have a self resonance in your trailer. How old are the leaf springs? Do they still have the braces around the individual "blades" they came with?
If you have bias ply tires no balancing will last longer than leaving the lot at the place which balanced them.....
 
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Natesms

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Original leaf springs. I do believe the packs still have the retainers on them. I have been debating the springs but have no way to test that theory out without just buying new ones. I'm not opposed to it if there is a high probability that could be the source of the issue.
 

90stingray

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At least pop the bolts out and look at the spring bushings. They are a replacable item.
 

K9Deuce

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I have had the same issue a few times through the years and it always been with tires. Once replaced the problem is solved. As previously stated the tires are rated for a specific speed but driving great then that should not cause your problem. Just be aware long term driving above the rated speed can cause issues in the long run.
 

kjsAZ

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The spring bushings are a start and cheap. There's no real way to test the springs short of some real test equipment. If they are older than 12-15 years I would replace them.
 

redneck joe

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and springs are cheap.


Check your bearings again in another 100 miles or so. Or I should say check for play they might have set in more and the nut can take a bit more turning to seat.
 

midcarolina

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dynamic balancing may help the problem floow the link below for more info......... I had a shake on my motorcycle that I could not cure tried everything, someone suggested dyna beads, and it totally cured the shake.
 

Natesms

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I've run 2 sets of tires with the same results so I believe it is elsewhere.

I went out and looked at the springs this morning. Nothing obviously wrong around the bushings, but I didn't have time to jack it up. I did notice that 1 spring appeared slightly more flat than the other. A tape measure showed a slight difference in distance between the frame and the top of the tube.

I looked up springs and they are cheap. I ordered a set. Lets hope this takes care of it!
 
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bruceb58

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Have you ever tried towing with another vehicle to see if it does the same? Is it just one stretch of road that this does this on or all roads?
 

Fleetwin

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Can you isolate which side is shaking or is it both?

An out of balance/out of round brake drum can certainly cause a vibration.

You can check for out of round by spinning the drum and looking. Out of balance requires removing it and putting it on a bubble balancer. Most brake drums are exterrnally balanced. You may see obvious signs of where a weight once was but is no longer.
 

Natesms

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Have you ever tried towing with another vehicle to see if it does the same? Is it just one stretch of road that this does this on or all roads?
I haven't been able to tow it with another vehicle. However, I tow multiple trailers with my truck and this is the only one with a problem.

All roads cause the problem. It does come and go though especially with hills. It's not consistent on the up or downhill part, I just notice sometimes the shake will go away when I'm running up and down hills.
 
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Natesms

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Can you isolate which side is shaking or is it both?

An out of balance/out of round brake drum can certainly cause a vibration.

You can check for out of round by spinning the drum and looking. Out of balance requires removing it and putting it on a bubble balancer. Most brake drums are exterrnally balanced. You may see obvious signs of where a weight once was but is no longer.


I believe the shake is on one side however I can't confirm it 100%. It looks like it shakes in the mirror, but the whole truck shakes like crazy so it is tough to tell. On that same side the bearings were hammered while the other side was fine so I believe it to be isolated.

I don't think the brakes do a thing. I will inspect the drums more closely when I get to the springs this week.
 

Fleetwin

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If the brakes are working, or not, wouldn't matter. The drums are heavy. If they are out balance, that may be the issue.

If you can isolate it, side to side, you can swap the drums, side to side, and see if the vibration follows.
 

hungupthespikes

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I believe the shake is on one side however I can't confirm it 100%. It looks like it shakes in the mirror, but the whole truck shakes like crazy so it is tough to tell.

This is a sign of wind buffering, "truck shakes like crazy" could be trailer, truck, but most likely the combination. The wind over/around/UNDER the truck at a certain speed then hits the turbulence from the boat and everything shakes. Not very common, but it does happen more often than you would think.
Try a different TV, and not just a different truck, but a TV that has different body lines......full size van, suv, 8ft bed pickup.....

First rule of thumb for trouble shooting a trailer/truck combination is change the TV.

good hunting
huts
 

redneck joe

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after pulling are the hubs different temps or hot in general that might tell you if brakes are grabbing for some reason.

if on hill that could indicate something with the truck - ie up hill is under load downhill under a 'reverse load' especially if using OD or second gear as a speed control. My ujoints went bad on my last trip and drove about 100 miles with it being really bad in the same speed range as you are talking about especially on the hills both up and down.

Have you had someone drive along side of you to look at the trailer and wheels (and truck)?

How much load difference is there in the other trailers you pull?



rj
 

Natesms

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I haven't had someone drive next to me but could do that.

Where could I take the drums to be balanced? I was just looking and I could get new drums with bearings for $80. I spent $58 a side on the bearings and seals yesterday!

I'm skeptical on the springs as well, however one side looked flat to me. The springs looked like they were wrapped a little odd. I'll take a picture later.

The other trailers I tow range in size and weight. My camper has a few thousand pounds on the boat and smooth as can be. The 2 flat beds tow well loaded and unloaded. It'll be a few days before I can get my hands on a good 2nd test tow vehicle.
 
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