Trailer troubles (1 Viewer)

[marcfj60]

My father recently picked up a small trailer to use for hauling stuff around. It's made from the rear frame and bed of a Chevy LUV (MIKADO) pickup, with the original axle and suspension still being used. The forward frame of the truck was used as well, such that the front part of the trailer is the frame cut and welded into an A-shape coming up to the hitch, probably about 6' ahead of the front of the bed.

This weekend was the first time we have used it to haul anything. It didn't do too well. Hauling it empty there doesn't seem to be any problem. But when I put ~500+ lb of weight in it, it becomes unstable above 15 mph. It doesn't take much to make it start a twisting motion, pivoting on the hitch ball.

The shocks aren't tough enough to dampen the motion, despite installing new shocks on it. I noticed that the springs are very light duty. Just putting 200 lbs (myself) in the bed causes the to compress significantly.

Does anyone have any experience with trailers or this type of behavior? I've been trying to think of what would improve the stability of this trailer. The two thoughts that come to mind are significantly stiffer springs and/or the installation of a sway bar.

It would be a great trailer for hauling extra gear while camping. It'd be neat to do something like Shawn did with his FJ40 trailer. I've also considered coming up with a swiveling pintle that I can swap out with the ball-hitch when going on terrain that would require the differential articulation of the trailer and towing vehicle. But as the trailer sits now, I don't want to ever use it again to haul any more than a couple hundred pounds.

 

[evanz80]

Hi Marc -

Sorry to hear about your problems with the trailer. It sure seems like it should be able to handle at least 500 pounds, if not double that. I've got a similar trailer made from the bed of a Ford Courier, and it's worked out great. I mostly use it to haul stuff to the dump (transfer station). I don't think I've had it up past 50 or 60 mph, but it's very stable. I'm afraid I don't have any good ideas for you, but hopefully someone here can give you some tips.

Evan

 

[pappy]

Check how the trailer was loaded:

From: etrailer.com | Tips on How To Tow a Trailer

Trailer Loading
The way you load the trailer can determine how easy you can tow it. While loading, keep in mind that the tongue weight should be 10% to 15% of the overall trailer weight. One of the main causes of trailer sway is not having a large enough percentage of trailer tongue weight compared to gross trailer weight. To help prevent the trailer from swaying back and forth, a few things can be done. Try placing heavier cargo in the front of the trailer, ahead of the trailer's axle. Also center the cargo left-to-right and use tie-downs to keep the load from sliding.

Trailer Sway can also lead to a loss of vehicle control. When starting out with a new load on a trailer, make sure it will not sway by gradually increasing your speed in intervals until highway speed is reached. If the trailer does begin to sway, try adjusting the cargo and equipment accordingly and then repeat the test. If repositioning the load and equipment did not help reduce the sway, a sway control or a weight distribution system with sway control may be needed.

 

[evanz80]

I think Jon is on to something here. Maybe Ali can post up with his trailer story with more details. The short version is that he was hauling gravel and too much of the weight had shifted to the back of the trailer. Not enough tongue weight and the trailer actually swung around and turned his 80 series 180 degrees on a rainy road. Luckily no one was coming the other direction! I must be getting old - how could I forget that?

 

[marcfj60]

I loaded the trailer at the front first and the load tapered off as the piles of concrete, tile and sand were added. I even tried to flip the drop reciever over (making a rise receiver?), thinking maybe there was a caster angle issue. The first experience with concrete and tile chunks had the trailer with a significant stink-bug effect, the toungue being pretty low to the ground. The second attempt was with new shocks, and I flipped the receiver and ball over such that the trailer set level unloaded and then it sloped slightly down to the back when it was loaded with a pile of sand. Both sceanrios resulted in the same instability. It was enough to feel it pusing the hundy's back end back and forth.

 

[sl33p3]

sounds like you were tongue heavy...? (no jokes please, it would kill me considering the amount of forced restraint i had to use to not make them myself ) big imbalanced loads either way are bad.

i don't think you could have caster issues from the rear axle of a pickup? did you mean caster in the trailer (i hope it has none) or caster of your hundy? less issues with caster and ride height with IFS right? my experiences with caster in my 80 say if it is low, (or negative like i had) the steering wheel sdoesn't return to zero when you let go and feel spooky... i never tried towing anything that way...

my .02$, now lets hear from an expert

-j

I loaded the trailer at the front first and the load tapered off as the piles of concrete, tile and sand were added. I even tried to flip the drop reciever over (making a rise receiver?), thinking maybe there was a caster angle issue. The first experience with concrete and tile chunks had the trailer with a significant stink-bug effect, the toungue being pretty low to the ground. The second attempt was with new shocks, and I flipped the receiver and ball over such that the trailer set level unloaded and then it sloped slightly down to the back when it was loaded with a pile of sand. Both sceanrios resulted in the same instability. It was enough to feel it pusing the hundy's back end back and forth.

 

[alia176]

it sounds like the "tail wagging the dog" syndrome when a trailer is either loaded improperly or built improperly. If the rear end of the hundy was shoved around then that is the start of the famous trailer sway. If you were to go faster, say above 45mph, that sway could potentially move the rear end of the hundy around and make you say funny <censored> things. When it happened to us, the trailer caused the 80 to go on a complete 180 w/o flipping either the 80 or the trailer. The road was wet enough to help us out in that way.

is the trailer balanced well? As in can you pick up the tongue easily when it's empty? If so, that could be a problem.

 

[marcfj60]

I thought the caster thing didn't make sense but my father told me to try it. The trailer is nearly perfectly balanced unloaded. It normally sits on the tounge unloaded. But when I picked it up, I put the spare tire in it right by the tailgate and that was enough to lift the toungue off the block it was on and make it tip over.

So are you saying that the load should have been biased to the rear of the trailer. I had it pretty much level with just a slight weight bias towards the front, since the tailgate was down when I was loading and I didn't want stuff to fall out.

 

[sl33p3]

hmm so you are saying the tongue weight wasn't too heavy? like about how heavy was the tongue if you tried to lift it at the hitch (i realize you might not be able to know now)? i'm sure our rigs have (by hitch class at least) a recommended max tongue weight. and negative tongue weight would be bad of course since for at least the reason of as soon as you uncoupled from the ball it would tip back and do bad things <insert censored words here>. but if it was pulling down the back of your hundy badly, i'm guessing it was too heavy. i think i recall ~200lbs tongue weight? or was it 500, can't remember. and from experience it is really easy to overload the tongue since we are all worried about it tipping backwards on us. and i'm pretty sure no ball hitch is really rated or expected to be lifted off the ball as opposed to held down on it.

i also think front to back weight distribution is completely independent to tongue height, within a range of angle (as much as the tip angle changes your center of gravity) providing it doesn't drag front or back parts (extreme angle). you'd be fine?

i guess another thought with concrete etc is did you just flat out exceed the weight that trailer could hold? i mean more from the geometry of the axle to tongue etc, vs just spring rating of the axle. seems like higher rated trailers always get longer and the axles arent' typically centered in the overall length. you might just be fighting geometry of the trailer more than anything? ie distance from load center (hopefully just in front of axle) to ball mount? since it sounds like an improvised trailer as opposed to a purpose built design/engineered type thing?

I thought the caster thing didn't make sense but my father told me to try it. The trailer is nearly perfectly balanced unloaded. It normally sits on the tounge unloaded. But when I picked it up, I put the spare tire in it right by the tailgate and that was enough to lift the toungue off the block it was on and make it tip over.

So are you saying that the load should have been biased to the rear of the trailer. I had it pretty much level with just a slight weight bias towards the front, since the tailgate was down when I was loading and I didn't want stuff to fall out.

 

[marcfj60]

I have no idea what the tongue weight was when loaded. I can only estimate maybe 500 lbs total weight inside the trailer so maybe 200 lbs tongue weight. The trailer itself weighs ~ 450 lbs. The unloaded tongue weight is in the neighborhood of 25 lbs. With more weight in front of rather than behind the axle, I'm sure I increased it a bit. There was no discernable sag to the rear end of the cruiser. Towing 'capacities' listed for the vehicle are 650 tongue weight and 6,500 trailer max.

I think I'm leaning towards the trailer's safe capacity only being a couple hundred pounds, with the current spring setup. If some leaves were added or new, heavier springs installed, then it might improve its stability.

 

[alia176]

I'm no expert but here's what I can't understand:

- if the trailer was overloaded, then it'd simply bottom out the springs. How would it an overloaded trailer try to control the rear of the vehicle unless there's a geometry issue? I dunno, just thinking out loud.
- if the tongue weight was so heavy that the rear end of the hundy sunk down a tad, then is it safe to say that there was plenty of tongue weight? Again, if the trailer was influencing the tow vehicle that badly then the distance from the hitch ball to the axle sounds inappropriate, like John mentions above.

- Wasn't a Chevy Luv a 1/4 ton pickup truck? So, 500 lbs sounds like it's not too bad considering there is no cab weight to influence the rear springs. Perhaps a tired set of springs are too much for the 500lb payload?

 

[frobuster]

OK, let's try a whole new approach; I think the problem you are having may be related to that 6' tongue. You are unable to get enough tongue wt. Too much leverage. Try loading the back of the hundy to mimic it???....Nah, don't think that would work.

 

[sirenmoses]

... The trailer is nearly perfectly balanced unloaded. It normally sits on the tounge unloaded. But when I picked it up, I put the spare tire in it right by the tailgate and that was enough to lift the toungue off the block it was on and make it tip over...

My pro-am opinion is that the problem lies here. A trailer should, even when empty, be weighted towards the hitch. Marc's 25lb weight sounds about right: I'll check mine later on w/a hanging scale, just for grins. It's not as heavy as 35lbs of dog food, I'll tell ya that.

The Mud Trailers section has a couple threads about weight ratios: what I remember is to be heavier towards the hitch, like 80/20. Personally, I go more 60/40 when I can.

My current beater trailer doesn't have shocks, just a minimal 2 leaf springpack w/a bowed mobile home axle. It has hauled everything: trash, firewood, gravel, dog show equipment (car camping w/ dogs, basically), with loads anywhere from 0lbs to 1200+. The most recent run was to Durango area at 75mph+. Yes, my cruiser can do that, tho not uphill.

The previous trailer was a Harbor Fright POS, which got overloaded everytime I used it: still no tailwaggin. It also jumped off the hitch a couple times (crappy screwdown attachment), which is why I'm such a believer in crossing the safety chains.

But then the 60 is a different beast, although tounge weight is 250lb and towing 2500: my buddy's Astro van is 500/5000....

how bout a picture, and some measurements: hitch to bed, hitch to axle, etc? I'm sure if we put our thinking caps on....

 

[SteveLCetc]

I have one like that from a Nissan "Hardbody" (sic) pickup. If the hitch is too high it does that - never tried too low. I needs to sit about level. It's also a problem if weighted in the back. Never had a problem below about 30 mph. Tongue weight is about 60 lbs - there is a plate welded on between the hitch and bed to add weight in front. Riding level and loaded toward the front it's fine to 80 mph. I'd try some permanent weight in the front (spare tire?) or toolbox or something. Tie some weight in front of the bed first and try that...

 

[marcfj60]

When I had the trailer loaded, the bump-stops were a couple inches from touching the axle. Unloaded they sit about 8" from it. I'm certain both times the trailer was tounge heavy, but I could never come close to a guess on the distribution percentages. Maybe I should remove the shocks and see if I get the same modal response. I'll try to take some photos and measurements the next time I'm at my father's house.

 

[SteveLCetc]

Is the tire pressure high on them? I would think that would help.

 

[marcfj60]

I set them at 30 because they were passenger vehicle tires, not load-rated.