Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

[Bronlonius]

My boat is a 12' tracker, it came on one of the DIY Northern tool bunk trailers. The trailer is basically 2 bunks, a bow roller, and 2 keel rollers. So far I hate this trailer. I spent a considerable amount of time tweaking the winch stand when I got the boat, the previous owner had mounted the winch way too low, to the point that it was digging the keel into the front keel roller and bending the sprockets on the winch. He also had the bow roller set up under the bow eye(a very bad idea), so I think the low winch mounting was an attempt to keep the bow from bouncing. Anyways, that part is solved, but I still can't seem to get this trailer to work very well when launching/retrieving. It always seems like the boat gets stuck on the bunks when launching, and simply doesn't want to line up correctly when retrieving. Usually I end up pulling the boat out of the water, and then lifting/wrestling the back of the boat so that the weight of it is equal on both bunks. When I got the boat, the bunks were very loose and could swivel/tilt very easily, which made it almost impossible to use. I tightened them up and it's a little better, but by design they still move into the wrong angle as I'm trying to get the boat onto the trailer.

These trailers come as a kit with the 8" wheels, mine has 12" wheels, so I think that part of the problem is that because of the increased height of the bigger tires, the trailer is at the wrong angle for the ramp I'm using. I do not want to put little tires back on, but I'm wondering if anyone has flipped the axle on one of these trailers to help lower it. There's not a lot of room between the inside of the spring and the frame, so I'm worried if I did this that the axle would bottom out on the frame.

Or, is there something I can do with the rollers/bunks that might help? I was thinking of raising the front keel roller, but that would mean yet another re-do of the winch stand, which would need welding because the bow roller is already as high as I can possibly get it. Or would raising the rear keel roller help? It's just barely touching the bottom of the boat, which I believe is the way it's supposed to be.

 

[RiverDewey]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

Can you provide a picture? It sounds a lot like mine, although mine came from Tracker.

 

[Dawg'sLife93]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

You can search craigslist for another trailer. I bought a 14ft older trailer in good shape for 125.00. I built a box on top of it for trash hauling, but still a good trailer. Might be able to find something that will work better for your boat for 100-200 bucks, then sell yours to recoup the cost.

 

[Bronlonius]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

Here's a pic of what it looks like. It comes as a kit from Northern Tool.

 

[Thalasso]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

If you flip the axle under the springs ( like your title suggests) you will be raising the trailer. You want the axle between the frame and springs
If your problem when launching is (hard to get off trailer) just back in untill the boat floats. When retrieving don't back in to far. This way the boat will line up on the bunks instead of floating.Or just put some guides on the rear.Just cover the fenders with water.Speaking of fenders, where are they.I would think that would be illegal on the highway.

 

[Bronlonius]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

If you flip the axle under the springs ( like your title suggests) you will be raising the trailer. You want the axle between the frame and springs

Sorry for any confusion, the trailer is currently Spring over axle. I want to lower it by making it spring under axle, which should drop it a few inches. The reason I want to know if anyone has done it, is that the space between the spring and the frame is pretty tight. The axle will fit in there, but I'm not sure how much the spring moves on the highway, and if the axle would end up hitting the frame or not.

 

[smokeonthewater]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

If you need to change the ANGLE of the trailer, consider a different ball mount.

To see if the axle will hit the frame, measure how high it will be and build something 3/4" taller out of balsa wood to duct tape in the space.... go tow the boat over some pretty good bumps at speed... if the balsa is broken you don't have room.

 

[Bronlonius]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

The balsa idea is a really good idea. I'll try that. The roads are horrible around me too, so I know exactly where to test it

 

[fishrdan]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

The balsa idea is a really good idea.

I've done the same thing with a ball of aluminum foil, foil crushes and maintains it's crushed height. (not talking about specs to to withing .0000001" )

I have Harbor Freight trailer with 12" tires that I modified into a boat trailer. I flipped the axle on top of the springs and added a 1" solid steel spacer block to get the trailer frame as low as possible.

 

[colbyt]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

There isn't enough detail in your photo to be sure but why are your bunks so high? It doesn't look like you need to miss any fenders.

Get the bunks as low and long as possible would be my advice.

 

[Bronlonius]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

The boat is a V hull, hard to see from the pictures, but unless I remove the rear keel roller entirely or do some fabrication, the keel is as low as it can go. I think that's the fundamental flaw in this setup, most 12' boats are flat bottom, so this trailer is designed for that. The crossmembers in the trailer are straight across, would really be nice if they were v shaped.

 

[RobWise64]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

In most cases you can mount the axle over or under the springs with no problem. The thing you usually have to worry about is fender clearance and you don't have any to worry about. Does your axle have a camber to it? If so, you'll either have to mount perches on the opposite side of the axle or drill holes for the spring bolts to seat in (on square axles). Springs don't usually flatten out enough to bottom out an axle against a frame, and even less likely with a light boat like yours. Maybe if we could see a picture that shows the axle and spring more clearly.

 

[colbyt]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

The boat is a V hull, hard to see from the pictures,.

Makes a lot of difference. Plan very carefully before you start. A different trailer may cost less.

 

[Bronlonius]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

Here's a better picture of the back of the trailer. As you can see, the keel roller is keeping it pretty high, because it's mounted directly on top of the crossmember. I wonder if making a bracket to lower the rear keel roller an inch or two(Mounting the keel roller off the edge of the crossmember, but keeping it high enough so that the keel still doesn't touch the crossmember) combined with the spring under conversion would be enough. The rear keel roller currently doesn't really carry much weight, it's more of a guide on... at least the way it's set up now the bunks are holding most of the weight at the rear.

 

[batman99]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

I have a Bayliner Capri single axle trailer that uses 13" trailers. IMO, this trailer sat "too low" to the ground. I looked at larger size tires (which meant costly larger size tires and larger size fenders), installing longer shakles (which couldn't easily be done) and a few other mods. In the end, I decided to take its existing single axle beam and "move" under its factory leaf spring packs. This raising the trailer approx. 4" higher. Axle beam is same level off the ground but its main chassis is higher off the ground. Being higher off the ground, the motor's prop is higher off the ground (even in motor's tilt position) and one can now see its underbelly rear ID lights much better as well. And, the trailer now has level stance - when connected to my Tow Vehicle as well. Win - win - win on many different fronts.

Only negative is its fenders are much higher from the top of its 13" tire. It looks like one is all dressed up and wearing short / flood pants. LOL!!! Perhaps this winter, I will lower its fenders 2" - using some thick steel plates. Very simple DIY mod - for a winter project. Other negative is the trailer must be backed into the water a little further. For example, backing in 12-16" more - for smooth boat launch and loading. So far, this isn't a problem. Only an observation.

With above +'s and -'s, moving the single axle "under" the factory leaf spring packs was a great idea. It works great or my trailer with 13" factory tires. And, glad I did it. And using factory U-bolts cost me NO cost doing this change either.

For your boat trailer, suggest re-position the axle "under" your trailer's leaf spring packs (perhaps existing U-Bolts can be used) and give it a try. If it works for your trailer, then great. If no good, then simply change back. If doing your own work, this "try it" test would be free.

 

[Thalasso]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

Your axles are already under the springs. Put them on top and it will lower the boat. Just make sure of your wheel and axle clearance

 

[Bronlonius]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

Your axles are already under the springs. Put them on top and it will lower the boat. Just make sure of your wheel and axle clearance

:facepalm: Yes, I know that. As I already pointed out earlier in this thread.

Would it be possible for a moderator to change the title of my post to something like "Modifying Northern Tool Boat trailer"? I didn't word the title correctly, and clearly people aren't reading the whole thread and instead just answering the title.

 

[Thalasso]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

I absolutely read your post and you did ask about changing spring location. I also recommended try launching deeper and retrieving shallower to your concern about boat not coming of trailer and not going on right.

"quote"
I'm wondering if anyone has flipped the axle on one of these trailers to help lower it. There's not a lot of room between the inside of the spring and the frame, so I'm worried if I did this that the axle would bottom out on the frame.

still can't seem to get this trailer to work very well when launching/retrieving. It always seems like the boat gets stuck on the bunks when launching, and simply doesn't want to line up correctly when retrieving. Usually I end up pulling the boat out of the water, and then lifting/wrestling the back of the boat so that the weight of it is equal on both bunks.

 

[Bronlonius]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

I absolutely read your post and you did ask about changing spring location. I also recommended try launching deeper and retrieving shallower to your concern about boat not coming of trailer and not going on right.

If you had taken the time to actually read the rest of thread after your first post, you'd see that I already responded to you the first time, and that I had clarified that my axle is under the springs. My original question was not about whether or not my axle is sprung over or sprung under, or which way would lower or raise the height of the trailer. The original question was whether or not anyone else had lowered this same trailer by flipping the axle, and whether or not the axle bottomed out on the frame when they did that.

I didn't bother answering your suggestion about launching deeper or retrieving shallower because I am already well aware of those concepts. But if you must know, I can't back my trailer in any deeper because my tow vehicle's trunk would fill up with water, and I'd like to be able to launch without getting my feet wet. That's the reason I'm considering modifying the trailer.

 

[Thalasso]

Re: Northern Tool Boat Trailer - can axle be flipped under leaf springs to lower it?

If you had taken the time to actually read the rest of thread after your first post, you'd see that I already responded to you the first time, and that I had clarified that my axle is under the springs. My original question was not about whether or not my axle is sprung over or sprung under, or which way would lower or raise the height of the trailer. The original question was whether or not anyone else had lowered this same trailer by flipping the axle, and whether or not the axle bottomed out on the frame when they did that.

I didn't bother answering your suggestion about launching deeper or retrieving shallower because I am already well aware of those concepts. But if you must know, I can't back my trailer in any deeper because my tow vehicle's trunk would fill up with water, and I'd like to be able to launch without getting my feet wet. That's the reason I'm considering modifying the trailer.

No need to get touchy. How about a trailer tongue extension to get the boat farther back so the car doesn't get swamped

Extend a hitch boat and sailboat trailer hitch extensions



Extend a hitch boat and sailboat trailer hitch extensions