Replacing trailer axle... what are the considerations?

[jimmwaller]

great, thanks @dingbat! I think I'll hammer test the frame and axle and assuming everything sounds good, just replace the hubs and springs (and just use my existing axle and frame).

Just to make sure this doesn't get buried...

I'm having a bit of a tough time finding a replacement axle. My axle is a square, 2x3 axle, with 75" spring centers, with a drop. The measurement between the brake flanges is about 81" and it's about 84.5" from hub face to hub face.

I'm seeing a couple of 2x3 drop axles, but nothing with 75" springs. Which dimensions can I play around with here? Could I switch from a drop to a non-drop-axle? Or use a different brake flange measurement, or hub face measurement?

I should add, when I say a drop axle, I don't mean "drop center" in that there's a bend in the axle. I mean that the axle is off center from the wheel center and has a plate to raise the spindle up, like so: https://www.easternmarine.com/8775-2-x-3-square-drop-galvanized-trailer-axle-6000-lb

Thanks!!

 

[Lou C]

Spring center dimension is something you really can't change but you can go wider on hub face to hub face dimension if you have to in order to get an off the shelf axle.
The other option is Champion Trailers in Slidell La. They will make a custom axle to your dimensions exactly how you want it. Takes a bit of time but they do excellent work, I had two trailer axles made by them. Here's a pic of the 6,000 lb drop 2x3 saddle center axle they made for me that replaced the 3500 lb axle they made for me back in 2004

 

[jimmwaller]

Thanks—another question. If I end up using my existing axle, at the moment, I have (very rusted) brake hubs on there. What are the considerations when buying new hubs? Do I need to buy brake hubs, or can I just buy a simple hub? If I need brake hubs, is it just a matter of buying any brake hubs with the right spindle size and a reasonable bolt pattern, or do I need to match with more specificity? I don't use my brakes or anything, but the current hubs look like brake hubs to me.
Thanks!

 

[dwco5051]

Towing Laws | Brake Buddy®

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[dingbat]

Thanks—another question. If I end up using my existing axle, at the moment, I have (very rusted) brake hubs on there. What are the considerations when buying new hubs? Do I need to buy brake hubs, or can I just buy a simple hub?

Depends on the load. Most States require brakes on at least one axle if trailer weight exceeds #3,000. Should check local requirements

 

[jimmwaller]

Depends on the load. Most States require brakes on at least one axle if trailer weight exceeds #3,000. Should check local requirements

oh.... yeah I guess I need brakes.

Two questions: One, my boat is stored—literally—about a block from the launch ramp. I'm kind of guessing because there aren't city blocks in the park, but it's about a 90 second drive with a 10mph speed limit. Still worth it to get brakes?

And then two: If I need brakes, are these relatively easy to install? I looked it up and it seems like a matter of buying brake hubs, installing them like a normal hub, and then installing a controller—is that correct? I only have a flat-4 connector, will that work? All of the instructions I see are for 7-pin connectors, which has me a little worried. If this adds $500-$1000 to my cost, I might just end up buying a new trailer after all....

Thanks!

 

[Horigan]

That trailer likely has surge brakes (my Calkin does). If you can confirm that by looking at the front coupler, you don't need a controller. Brakes are easy to install with the hardest part being bleeding them with the surge brake coupler. You'll need to confirm the surge controller is good. There should be a master cylinder reservoir (like on a car) at the front. If it's full of brake fluid, that's a good sign. If it's dry, you will likely need a new master cylinder, or a new entire surge coupler.

You want brakes to be legal and to cover your butt if you get into an accident in that short trip to the ramp.

 

[JimS123]

If it has brakes a 4-pin plug will not work. Even surge brakes need 5 pins.

 

[dingbat]

and then installing a controller—is that correct?

Only if you go with electric brakes. Surge requires nothing.

Comes down to what's cheaper....a surge coupler or a electric brake controller

I only have a flat-4 connector, will that work? All of the instructions I see are for 7-pin connectors, which has me a little worried.

A 7 pin is required to support electric brakes.

A flat- 4 wire connector will support surge drum brakes with free backing pads.

 

[jimmwaller]

I see, thank you all. I don't have a surge coupler but guess I'll put one on since I only have a 4 pin. I think my plan for now is to rebuild the axles (if necessary), leaf springs, hubs, etc. and just make sure my hubs are brake hubs. And then keep my eyes open for a used surge coupler in the meantime. Do I need to get any particular hub/coupler combination, or will pretty much any surge brake hub work with basically any surge coupler? And I can add the surge coupler on whenever I find a decent used one?

Thanks!

 

[jimmwaller]

oh, alternatively... is there a good marketplace for user trailers? I don't know of any, and craigslist is not being particularly useful... not a lot of trailers for 22 footers if you're not in Florida, apparently

 

[dingbat]

Do I need to get any particular hub/coupler combination, or will pretty much any surge brake hub work with basically any surge coupler?

Match coupler with brake type.
Drums need a different coupler than disk brakes

And I can add the surge coupler on whenever I find a decent used one?

A used coupler is just asking for problems.

 

[JimS123]

A flat- 4 wire connector will support surge drum brakes with free backing pads.

Yes that will work, but its a PITA. You have to remember to get out of the car and finagle the trailer every time you want to back up. Adding the extra wiring isn't that costly.

You say you only have 4 pins now. Is that on the trailer too? If so, than right now you don't have brakes at all. Is that right? If you, adding brakes is more than simple hubs and coupler. You need to run hydraulic lines as well.

 

[jimmwaller]

@JimS123 Yes, the trailer has 4 pins right now, but it also has brakes, and no surge coupler, so... I'm not sure what's going on there, ha. I'm mostly trying to figure out the cheapest way to get brakes on there—I really do drive 90 seconds to the ramp and nowhere else. Happy to run wiring or whatever to do the actual work, but in a perfect world, I'd just replace the hubs/axles now (so I can get back into the water!) and just add in the brake controls (whether surge or electric controller) later.

 

[dingbat]

Yes that will work, but its a PITA. You have to remember to get out of the car and finagle the trailer every time you want to back up.

No need to get out....Uni-servo free backing brakes are just that, trailer is "free to back" w/o intervention.

Free-backing brakes let your trailer move in reverse without the brakes being activated by your surge actuator. These brakes are needed if your actuator does not have a reverse lockout, which is a mechanism that ensures that the actuator does not activate when your rig moves in reverse.

 

[Lou C]

If it has brakes a 4-pin plug will not work. Even surge brakes need 5 pins.

Unless you install free backing surge drum brakes in which case no solenoid needed, the 4 pin is fine. These are free backing drums, the front shoe has a section that falls away from the drum when moving in reverse, so that the hydraulic pressure applied by the wheel cylinder does not create braking action. I've had em for years and they work well, never had problems backing up. In this pic you can see the difference between the 10" and the 12" brakes. If you have an axle with a 5 hole flange (as are common on 2x3 axles with #42 spindles) you can use 12" brakes. Having had both the 12" units stop RIGHT NOW.

 

[Lou C]

Towing Laws | Brake Buddy®

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keep in mind this refers to towing cars behind RVs, not the same standard as trailer brakes for a separate trailer.

 

[Lou C]

@JimS123 Yes, the trailer has 4 pins right now, but it also has brakes, and no surge coupler, so... I'm not sure what's going on there, ha. I'm mostly trying to figure out the cheapest way to get brakes on there—I really do drive 90 seconds to the ramp and nowhere else. Happy to run wiring or whatever to do the actual work, but in a perfect world, I'd just replace the hubs/axles now (so I can get back into the water!) and just add in the brake controls (whether surge or electric controller) later.

Does it have hydraulic brakes or electric? Wires heading to the back of backing plates or a brake hose? If no surge coupler they could have been electric brakes. If what you are towing is heavy enough to need brakes it is not a big deal to install a surge brake system. If in freshwater if you want to spend a bit less you can use galvanized electric brakes, but have to have a brake controller wired in to your tow vehicle. Surge brakes, once you have them installed, need no controller, they can be towed by any appropriate sized tow vehicle. First make sure that trailer is structurally sound before putting cash into it. The galvanized axle may be OK if the spindles aren't tweaked by bad bearings. Replace the springs, ubolts and add brakes to an other wise solid trailer then you're in good shape.
I've done my old trailer over 2x in 20 years.

 

[jimmwaller]

@Lou C yeah... I guess saying it has "brakes" was a bit of an overstatement. It has brake drums that are pretty incredibly rusted out, but they're not hooked up to anything, so I have no idea whether they were hydro or electric at one point!

 

[JimS123]

If they were surge brakes, you would think that the coupler would pr proper and oil lines would be everywhere. If they were electric brakes you would think it would have a 7-pin.

Knowing some of the abortions I've seen over the years, I'm going to propose a theory here.

The trailer has (had) electric brakes. They quit working so a PO simply stopped using them and replaced the plug with a 4-pin, simply connecting it to the lights.