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View Full Version : Dovetail trailer dragging solutions?


beransfixitinc
01-19-2005, 12:02 AM
Hi, recently we purchased a 12' trailer with a dovetail end, thinking this would make it easier for loading equipment. Well, anyway.. that's a different problem..

Current problem is the back of the trailer only clears a smooth, level, surface by about 6"... if that much.

We have heard a rumor that there is some type of solid steel wheel that can be mounted under the back of the trailer to keep the angle iron from dragging over high spots. We've already brought back a few nice size chunks of roadbase (and large rocks) from having to drive over roads that are being redone and need to find a way to increase the distance from the trailer to the pavement on the trailer.

Are there maybe spacers that could be installed in the springs to raise the whole trailer?

Any help, sooner the better, would be appreciated.

green814
01-19-2005, 12:28 PM
When the trailer is hooked up to the truck & loaded, is the trailer level or is the tongue higher & the rear lower? If so, just buy a drop ball mount to level the trailer. Otherwise check w/ r/v suppliers. I have seen motorhome & long 5th wheels w/ wheels mounted underneath at the back to stop dragging.
Chris

beransfixitinc
01-19-2005, 01:53 PM
When the trailer is hooked up to the truck & loaded, is the trailer level or is the tongue higher & the rear lower? If so, just buy a drop ball mount to level the trailer. Otherwise check w/ r/v suppliers. I have seen motorhome & long 5th wheels w/ wheels mounted underneath at the back to stop dragging.
Chris

Well, I've got an almost 5 or 6 inch drop hitch on it now. The problem is these roads around here.. going from a main "road" to a side street has such a dip, that the trailer is scraping the road. I guess as long as the angle iron is strong enough to not break apart, we'll just keep leveling off the roads when we drive over them :cool2:

Guthrie&Co
01-19-2005, 04:51 PM
just get the rollers.

beransfixitinc
01-19-2005, 05:53 PM
just get the rollers.


Well, yeah, but what are they called, and where to get them?

riches139
01-19-2005, 08:21 PM
www.servicecaster.com

Guthrie&Co
01-20-2005, 10:22 PM
Well, yeah, but what are they called, and where to get them?
buddy i have no idea. first place i would go would be a trailer dealer

wroughtn_harv
01-21-2005, 07:17 AM
Take it down to your welding shop. They'll know how to fix it.

The problem with the RV roller is they're made for heavy trailers that occasionally hit. And there's usually a little built in space to put the roller so that only the business end is exposed.

With your dovetail there isn't that space to tuck up a good large metal caster.

What they might have to make up is a two brackets that are very low profile with replacable steel wheels or even something like using pieces of half inch wall tubing over one inch pins. In effect rollers instead of wheels.

If you decide it's really too complicated an issue to deal with consider this. Every brace and weld in your trailer is designed to work against a specific force. Every time you scrape and drag you're putting forces on those braces and welds they weren't designed to accomodate. Sorta like having a mower designed for lawns being used occasionally as a tub grinder for construction debris.

beransfixitinc
01-21-2005, 08:53 AM
Take it down to your welding shop. They'll know how to fix it.

The problem with the RV roller is they're made for heavy trailers that occasionally hit. And there's usually a little built in space to put the roller so that only the business end is exposed.

With your dovetail there isn't that space to tuck up a good large metal caster.

What they might have to make up is a two brackets that are very low profile with replacable steel wheels or even something like using pieces of half inch wall tubing over one inch pins. In effect rollers instead of wheels.

If you decide it's really too complicated an issue to deal with consider this. Every brace and weld in your trailer is designed to work against a specific force. Every time you scrape and drag you're putting forces on those braces and welds they weren't designed to accomodate. Sorta like having a mower designed for lawns being used occasionally as a tub grinder for construction debris.

What I was thinking of, from looking around, would be to get something like these http://www.campingworld.com/browse/skus/index.cfm?skunum=18303&affiliateID=577&siteID=nGt.Iox5rjI-yW60u5NoLGykwdYUjp1sTw and weld some square tubing up under the angle iron to weld these to.

Mickhippy
01-21-2005, 09:07 AM
What about attaching some large bearings somehow? Maybe some large truck type bearings!

get someone to make up a roller like the mower stripe rollers that go the width of the tail!

edit... Just checked that link above and thats what I was talking about, the bearing looking roller!

greendave
01-21-2005, 04:01 PM
What I was thinking of, from looking around, would be to get something like these http://www.campingworld.com/browse/skus/index.cfm?skunum=18303&affiliateID=577&siteID=nGt.Iox5rjI-yW60u5NoLGykwdYUjp1sTw and weld some square tubing up under the angle iron to weld these to.
That'll work just fine, I would think. We've got a set of factory installed rollers like that on our Bluebird, they haven't given up yet, despite holding the ass end of 40,000lb coach off the pavement many, many times!
David

wroughtn_harv
01-21-2005, 08:56 PM
A couple of months ago I installed a pair of those on a fifth wheel travel trailer. It's the biggest and most elaborate travel trailer I've ever been around. His toter is a single axle new Peterbuilt. The trailer had dual tandems instead of just tandems. I'd never seen that before on a travel trailer.

When I installed them I went through some effort to mount them where they just didn't hang down. I wanted them stable and I wanted them to protect the chassis. And I believe removing three inches of clearance even if it's roller bearing'd does more harm than having the chassis drag occasionally.

So I had to mount them where they only were exposed about three eighths of an inch below the chassis.

Clearance has to be considered. Just adding a rolling device isn't the whole answer sometimes. It's basic problem solving. You have to look at the whole picture and then decide what needs to be changed to keep everything else as it was engineered.

An example would be a trailer where the sides were an integral part of the deck. The sides were engineered to be strong against tension, or being pulled upon. But you put the rollers on the ends and forced them to be working against compression, squeezed. Over time you'd notice fractures and the cure for the dragging of the chassis was causing more structural damage than the original problem.

beransfixitinc
01-21-2005, 10:08 PM
wroughtn,

so, are you saying that just letting the trailer back drag the ground all the time is better than trying to stop it from doing it? If we had known the drop was going to be so drastic and low, we would not have ordered it through the guy that way.

Guthrie&Co
01-22-2005, 12:27 AM
Take it down to your welding shop. They'll know how to fix it.

The problem with the RV roller is they're made for heavy trailers that occasionally hit. And there's usually a little built in space to put the roller so that only the business end is exposed.

With your dovetail there isn't that space to tuck up a good large metal caster.

What they might have to make up is a two brackets that are very low profile with replacable steel wheels or even something like using pieces of half inch wall tubing over one inch pins. In effect rollers instead of wheels.

If you decide it's really too complicated an issue to deal with consider this. Every brace and weld in your trailer is designed to work against a specific force. Every time you scrape and drag you're putting forces on those braces and welds they weren't designed to accomodate. Sorta like having a mower designed for lawns being used occasionally as a tub grinder for construction debris.
i doubt very seriously that draggin a trailer would hurt a weld. yeah it might grind it down a bit. that weld wont even feel it. if it was welded with a 7013 welding rod it would have 70 thousand pounds of tensile strength. which is a pretty common rod.

wroughtn_harv
01-22-2005, 08:45 AM
wroughtn,

so, are you saying that just letting the trailer back drag the ground all the time is better than trying to stop it from doing it? If we had known the drop was going to be so drastic and low, we would not have ordered it through the guy that way.

Under some circumstances. Let's say you run your trailer down to the welding supply and you have two of those above mentioned bearings. He welds them on to the back of your dovetail. You now have lost an additional three and a half inches of clearance.

When your casters engage the weight of trailer is now transfered to the coupler and the casters. Chances are your trailer has light construction siderails. These not only keep things in the trailer. They also assist in the main framework of the trailer to keep the trailer straight under load. They work under tension. Think of tension as attempting to pull apart. An eighth of an inch cable is more efficient at tension, being pulled against, than it is in compression, squeezed together.

So when you suspend the trailer from the bearings and the coupler all those welded joints and materials are being subjected to loads they're not designed to resist.

You do need to fix the scraping. It is not good. And those bearings would be the best way I know to do it besides reengineering the dovetail. However you want the bearing surface to only be exposed at an absolute minimum. And eighth of an inch would be a what I'd recommend.

If I was to do it I cut a slot in the angle iron being scraped wide enough to accept the bearing cradle. I would weld the cradle in where the bearing itself sat an eighth of an inch below the lower edge of the angle iron.

This will incroach into the dovetail deck. So this must be placed where it gives you the least chance of tripping someone walking up the dovetail or catching equipment going up and down the dovetail.

I would also add inspecting welds as part of my maintenance program. Welds rarely break in themselves. Usually it's the material next to the weld that breaks.

The next time you have a dovetail made consider what I once did for a custom landscape bed on a UD (Nissan). I made the dovetail with a folding ramp. But the dovetail itself was hinged and underneath was an enclosed area for tools. It was a dovetail with a trunk if you will. When the ramp was up and locked into place it prevented removing the big equipment. And since the cover over the dovetail couldn't be opened without the ramp down the tools in there were secure also.

wroughtn_harv
01-22-2005, 08:53 AM
i doubt very seriously that draggin a trailer would hurt a weld. yeah it might grind it down a bit. that weld wont even feel it. if it was welded with a 7013 welding rod it would have 70 thousand pounds of tensile strength. which is a pretty common rod.

I guess I didn't explain myself very well. Let's use an example from everyday life that is probably easier to understand.

You're picking your nose. Someone bumps your elbow. Where do you feel the pain?

The welds in other parts of the trailer is your nose. The bottom angle iron of the dovetail is your elbow

I hope that helps.

traman
01-22-2005, 09:48 AM
sometimes its as simple to just get bigger wheels or tires for the trailer higher profile and the like go from a 14inch rim to a 17 or if it a p70 go to a p75 or 80 the sidewall height of the tire .there usully enough room for fender clerence.

beransfixitinc
01-22-2005, 05:17 PM
Here are some rough photos of the back end of the trailer... Also, one of the front of the trailer to show that it is down as far as it can go in the front.

i_plant_art
01-22-2005, 08:34 PM
by the looks of the pics that particular trailer doesnt/shouldnt have had a dove tail built on it. why the manufacture did that is beyond me. it looks as if the gate on it is only 4 feet or even smaller than that in length. is this so? it so then that would explain the dovetail but it could have been avoided by putting a longer gate on the trailer such as a 5 foot. did you buy this trailer new from a dealer recently or from an individual? if you got it from the dealer recently i would suggest taking it back to them and explaining that it just isnt working out for your needs and would like to return/switch it for a different one. you you got it from an individual then i would suggest selling it yourself even if at a small loss and get one without a dovetail. getting larger rims and or tires will only cost you more money, on top of what you already paid and could still have more problems with it. for what its worth i think that in the long run this trailer might be more of a hassle than its worth.

grass_cuttin_fool
01-22-2005, 08:44 PM
What would be the posability of mounting the springs on top of the axle instead of below it. That would raise it 3 plus inches

wroughtn_harv
01-22-2005, 09:41 PM
Here are some rough photos of the back end of the trailer... Also, one of the front of the trailer to show that it is down as far as it can go in the front.

The way I'd fix the trailer is I'd place the angle iron that's on the back of the trailer forward about a foot. And have the bracing at the back no thicker than the planks. I wouldn't lose any strength because the cross piece and it's strength would still be there. I'd just move it to gain clearance.

You could raise the trailer with a tire size change or placing the springs on top of the axle. If it has brakes make sure you relocate the spring perches on the axle instead of just rolling it over.

If you do that then you have to adjust either the coupler's height or the hitch on the truck's height so the trailer still runs level.

From my perspective it appears the trailer was made by a weldor and not a trailer fabricator. Very poor design, the way the angle iron is placed across the back, hanging down.

The dovetail design is very similar to a common car hauler trailer's. The difference is the misplaced angle iron across the back. Have to wonder why it was done like that.

It wasn't built at the high school as a project was it?

beransfixitinc
01-22-2005, 10:01 PM
The trailer was purchased new from a "dealer" (selling trailers is not his first priority). They come out of Hillsboro, TX. I think the manufacturer is something like Diamond Trailers or something like that. When we were ordering the trailer, we were told the gate was only like a two foot gate, and this would have been clearly too much of an incline. We asked if there was a dovetail design that would have a slight slope in the back. Well, so, this is the trailer that showed up, only the gate is a little close to, if not a little over 3', so a 3-4' gate would have been ok with just a flat rear. Will have to check on the springs.. never thought to pay much attention to that aspect.

ProSvcs
01-30-2005, 10:26 PM
Please dont continue too use it as a road scraper, (been there done that) The whole gate will come off at the most inopportune time. A car was following me real close when i went doen a dip in the road slow, The gate came completely off. It broke the welds. The gate fell backwards and completely crushed the hood of the car. It cost me over 3000.00 to repair that car.

I welded the gate back on then welded four brackets to the crossmember closest to the back. I used four solid spongy whelbarrow tires (The good one with the bearings). I mounted them so that they would contact the ground when the gate was 2.5" from the ground with the trailer fully loaded. Tis has worked great and cost me 250.00 for the tires and the 1/2" steel.

Jim

mission007
02-07-2005, 12:02 AM
Might Be Best To Try & Sell It Or Trade & Save Your Self A Lot Of Trouble Seems To Me That Dovestail Not Build Right Any Way