Trailer Sag

[Chris]

I'm trying to get my trailer ready to go out. When I blew out my back a year ago I left it until now only to find that I never winterized it. That wasn't on my mind but now it is since numerous plastic water carrying parts failed due to freezing. Duh. Those are fixed I hope but that's not my question.

Since I carry my spare on the rear bumper I always tossed it in the truck when hauling the trailer. Now that 50lbs is beyond what I can lift so I decided to try an extender which allows me the leave the spare in place. I understand the extension increases tongue weight but the sag I get is too much - probably 4" or so.

Air bags? Heavier rear springs! Remove the extension? What do you folks suggest?

It's been a freakin' year since I've been on a trail or used the trailer and I need to get out!

[xaza]

What about adding a mount to back of camper to move spare to there and eliminate the extension. First suggestion would be a load stabilizer but it won't work with extension I don't think. Air bag assist would work also but would be considerably more expensive.

[Eagle6]

I guess my first question would be your tongue weight? Is the trailer packed any differently that is putting more weight up front the in previous years?

Second, if not, did moving the tire into the truck really shift that much weight to prevent it or are you using more drop now? It would seem to me that if the spare were in the back you still had the same weight behind the rear tires of the truck. One other thought up front. You might not be able to lift the tire any more. How about a ramp to get it inside the vehicle?

[Chris]

What about adding a mount to back of camper to move spare to there and eliminate the extension. First suggestion would be a load stabilizer but it won't work with extension I don't think. Air bag assist would work also but would be considerably more expensive.

But I wouldn't have a spare when running trails and I have my trailer spare back there already. By load stabilizer are you referring to a weight distributing hitch? I'm considering something like Air Lift bags.

[Chris]

I guess my first question would be your tongue weight? Is the trailer packed any differently that is putting more weight up front the in previous years?

Second, if not, did moving the tire into the truck really shift that much weight to prevent it or are you using more drop now? It would seem to me that if the spare were in the back you still had the same weight behind the rear tires of the truck. One other thought up front. You might not be able to lift the tire any more. How about a ramp to get it inside the vehicle?

It's my understanding that moving the hitch back increases the tongue weight thus increasing the sag. My truck is rated at 7500lb trailer and 750lb tongue weight. Amy trailer is only 3,000 lbs which is well under the limits. I think the change is related to the longer hitch because my springs couldn't have changed much over the last year since it's hardly been driven.

I can can easily get someone to toss the tire in back but I have enough crap in back already. Expense wise that's the most sensible thing to do.

[Eagle6]

IDK, I'm just looking at the cheaper options before going the more expensive routes. Seem to me, that moving the stuff in the back to inside the trailer for the haul and a ramp to roll the tire into the back of the rig is the least expensive option. I agree if you keep a lot of junk in the back of the truck all the time for daily driving, you have trades. Leave the tire on for daily driving. Pull it off only for towing. It sounds to me you have the problem of lifting it either way if it is on the back. And you will still need to lift the flat back up and bolt it on.

[Chris]

I appreciate cheap! I have tools, recovery gear, etc in the back in 3 boxes that each weigh more than I'm supposed to lift right now. Maybe my 6 month checkup on Wednesday will up my limit and resolve everything but I doubt it.

Just getting it off the back is an issue regardless of the circumstances. I've learned to take advantage of offers to help when offered which covers trail runs since we have so many good people here. At RV parks it's not so easy since it's mostly old farts like me. :D

[Hypoid]

What about an extension for the trailer tongue, instead of the hitch?

[Chris]

What about an extension for the trailer tongue, instead of the hitch?

That's lot of cutting & welding Mike. I'm leaning heavily to having my son toss the spare in the back and I'll strap it in place. Cheap, effective and no work on my part! :D

[newracer]

I'd redistribute items in the trailer to reduce the tongue weight.

[FINOCJ]

What about an extension for the trailer tongue, instead of the hitch?

I kind of agree with this as a good long term solution. I think what is happening is not the amount of weight on the tongue, but how far behind the tow vehicle axle that weight is now being applied. You can think of the tow vehicle axle a bit like a fulcrum and the distance from the axle to the ball on the hitch as a lever arm that multiplies the force at the fulcrum as it gets longer. As a physics teacher, I have the kids model a similar idealized situation to determine how much more a spring with a given spring constant (stiffness) is affected by the length of the load lever. In an ideal situation, increasing the length of the hitch ball from the axle by 25% will increase the force applied by about the same percentage and thus compress the springs by a distance of about the same percentage of their total length. In reality, its probably not quite that much, but it still wouldn't take much to get the rear springs to compress by 3-5 inches inches with the same tonque weight.

Now if you lengthen the tonque without moving the hitch ball back, you will keep the 'lever arm' the same (distance the hitch ball is from the tow vehicle axle). Of course, the longer tongue will add that new weight almost exclusively to the tongue. But I am guessing that is a much smaller % (30lbs out of 750lbs) than moving the hitch ball back (say 1ft out of 3 or 4 ft?).

[Chris]

I'd redistribute items in the trailer to reduce the tongue weight.

This is my travel trailer Michael, not much can be redistributed.

[Chris]

I kind of agree with this as a good long term solution. I think what is happening is not the amount of weight on the tongue, but how far behind the tow vehicle axle that weight is now being applied. You can think of the tow vehicle axle a bit like a fulcrum and the distance from the axle to the ball on the hitch as a lever arm that multiplies the force at the fulcrum as it gets longer. As a physics teacher, I have the kids model a similar idealized situation to determine how much more a spring with a given spring constant (stiffness) is affected by the length of the load lever. In an ideal situation, increasing the length of the hitch ball from the axle by 25% will increase the force applied by about the same percentage and thus compress the springs by a distance of about the same percentage of their total length. In reality, its probably not quite that much, but it still wouldn't take much to get the rear springs to compress by 3-5 inches inches with the same tonque weight.

Now if you lengthen the tonque without moving the hitch ball back, you will keep the 'lever arm' the same (distance the hitch ball is from the tow vehicle axle). Of course, the longer tongue will add that new weight almost exclusively to the tongue. But I am guessing that is a much smaller % (30lbs out of 750lbs) than moving the hitch ball back (say 1ft out of 3 or 4 ft?).

I won't admit how many times I read this James but I agree that Mike's suggestion and your explanation are spot on and a good solution to my problem. I'll consider it in the future but for now I'll keep it simple and remove the extension and get my son to toss the tire in the truck.

[FINOCJ]

"Long term solution" as in it may take a long time to get to it :thumb:

[newracer]

What's on the trailer tongue in front of the propane tank?

[Brad]

I would say to add airbags to level your load. Very common procedure for this very issue. As my rig has a full air suspension and having hauled my toolbox with a trailer twice it is nice when I start my rig after loading it and watching my rig just inflate the rear springs to level it.

[JandDGreens]

Good read, this info is going to be helpful for me also, Thanks guys!

[TJS86TOY]

Chris, I second the airbags. I put them under the Ford F350 for the 2500# Overhead camper. Very stable and good ride with them. However, as nice as they are, if you are putting them on a rig that sees offroad, say goodbye to your flex.

[Chris]

What's on the trailer tongue in front of the propane tank?

The tongue jack is all that's there.

[Chris]

Chris, I second the airbags. I put them under the Ford F350 for the 2500# Overhead camper. Very stable and good ride with them. However, as nice as they are, if you are putting them on a rig that sees offroad, say goodbye to your flex.

My understanding is that they're kept at 5 psi when not needed, would they still interfere with what little flex I have?

[TJS86TOY]

My understanding is that they're kept at 5 psi when not needed, would they still interfere with what little flex I have?I would say yes. On my Ford at 5 psi when empty I mabey have 3-4" to play with. I don't even hit my overload springs. Of course you have a smaller lighter rig so it may react different. Just keep in mind they where designed for load carrying and nothing else. There may be ones designed for allowance of flex but never researched it. Do a quick search on the pirate board, they might have some info on that.

[Heather]

My husband bought the cheapest airbags they had at 4WP, and he loves them.

[Chris]

I decided that doing it right was the way to go, no air bags. Got a weight distributing hitch instead so it solves the sag and leaves my truck as is when disconnected.

[Eagle6]

Works. But it was still a great discussion.

[Brad]

Who says that's "doing it right"? :p

[Chris]

I do Brad! Primarily because it leaves my truck as is. Unfortunately it leaves a hole in my wallet too.

[FINOCJ]

I like that solution as well! Hope connecting the support chains to the pivoting pin hitch is okay for your back - might still need your son to do that part but I like not messing your truck.

[Chris]

I expect to be able to do it James. If I can't my wife should be able to. Hoping for less restrictions when I see my surgeon Wednesday.

[Chris]

Need to make final adjustments but it's within 1" of where it needs to be. 3.5" of sag already eliminated. I'll get to the final adjustments and tightening tomorrow.

Very cool design, no chains, it uses an "L" bracket on a small platform to hold the bars in place. It's a lousy pic since it was getting dark.

[Jim]

Looks quite good!

[xaza]

nice

[Brad]

I do Brad! Primarily because it leaves my truck as is. Unfortunately it leaves a hole in my wallet too.
You know I was joking, right?
Whatever works for you.

[Chris]

Of course I do, I'd have a LR style auto leveling air bag system installed but the cost would be more than my truck is worth! :lmao: