M416 handling question

[Rotors1]

I have a M416 trailer. Axle replaced with jeep 5 lug. New '12 JK wheels and tires on it has pintails hitch on it.
While driving on highway sometimes if bumps or uneven surfaces are crossed the trailer gets a horrible back and forth sway. Uncontrable and the only way to stop it is hit the brakes. Had it loaded about 300lbs, pretty evenly laid out. Pretty scary when it happens, especially if some one right behind.

Any thoughts on what to check or change?

Thank you

 

[shogun]

First and most obvious (along with hazardous) is the CG. The load should be adjusted so you have positive tongue weight, IOW it should not be raising up on its own or over bumps. Some folks pull a number out of the number plucking place and say 10% of load weight on the tongue. I dont buy that and generally run maybe 50-100#, so you can relatively easily lift it by yourself. You should be able to hear it lifting up in the pintle if its too light. I have run them with pretty close to balanced CG, maybe 10# of tongue weight. It works, doesnt go unstable, but a little too close for comfort.

 

[brian90744]

extent tongue helps

I agree with SHOGUN, and extended tongue by 12 or more inches helps. post some pic's of your M416.=brian

 

[Kmrtnsn]

What is the load in the trailer and the tire pressure? What speed are you towing at. I'm going to surmise that you are experiencing a combination of factors; too light, too short (tongue length), over-inflated for the payload, and towing too fast.

 

[hairy_apple]

I found mine got a bit funky on me on our last trip, but we were going too fast, and the road was really rough... highway 80 going over Donner Summit is so rough from chain damage, I think it got the trailer swaying and I was also going faster then I should have.

 

[Rotors1]

So rechecking we might of been a little lite on tongue weight. Tires were at 35psi. We were traveling between 65 and 75 on I-25. Here are some pictures. Lights and chains not hooked just dropped it on for the pic.

 

[RagnarD]

Trailer also looks tongue high.

 

[Robert Bills]

Based on my own experiences with military 1/4 ton trailers and your photos:

35 psi is too much pressure. Try 25 psi.

Tongue weight that is too light is often the cause of the symptoms you describe. Rearrange your load to increase your tongue weight. I run my Bantam balanced 60% in front of the trailer axle and 40% behind with a full load, and heavier toward the front when it has a light load.

Try to lower your tow hitch to level the trailer if you can. If you can't adjust the hitch you might want to experiment with even more of the load in front of the trailer axle. (The key is how the trailer is balanced - not so much whether it slopes forward or back.)

I have towed my Bantam T3-C at 75+ mph for thousands of miles with no issues, but this was after I determined the optimum tire pressure and load balance by trial and error.

 

[vegasjeepguy]

Shocks installed? I had a similar issue on highway until I installed shocks.

 

[brian90744]

trailer tongue too high on the jeep.

Trailer looks tongue high,, Would be best to level the trailer by moving the Lunette up to the top hole. this will help reduce sway =brian

 

[Kmrtnsn]

Shocks installed? I had a similar issue on highway until I installed shocks.

Judging by the appearance of the trailer, the shocks were leaking and bad some time during the first Nixon administration!

 

[vegasjeepguy]

Judging by the appearance of the trailer, the shocks were leaking and bad some time during the first Nixon administration!

When I bought my trailer here locally there were no shocks installed. Once I got them installed the trailer handled all road and offroad conditions like a champ and tracks behind my Jeep really well.

 

[NORDFORD]

Your trailer needs to sit level when empty for sure and level to slight down in the front when loaded. Get started with that and it will improve. The pintle hitch also allows movement. If the trailer is tipped back, couple that withthe pintle hitch movement and there you have most of your problem.

 

[Vinman]

Trailer sway is almost always caused by insufficient tongue weight. In fact, I would rather have way too much tongue weight that slightly not enough.
I pull a 16' enclosed tool trailer regularly with total trailer weight being just under 4,800 lbs. The way I have it loaded the tongue weighs about 1,000 lbs and I have NEVER had it sway even the slightest.
The general rule of thumb is minimum 10-15% tongue weight and like I said, I would rather have more than less.

The only incidence I had of trailer sway was a very light weight trailer I built (closely resembled yours but only about 300-350lbs empty) and I thought I was being smart and running about 15 psi. I guess it didn't sway, it was more like "hopping" side to side. I increased tire pressure to 25 psi and the trailer followed perfectly afterwards.

Good luck.

 

[mep1811]

I agree you need shocks and lower air pressure.