View Full Version : Axle replacement tandem axle trailer

06-20-2011, 12:53 PM
I will replacing my front axle shortly. I know a few of you have done this anad I'm looking for any pointers. After staring at the axle for a while, I think my main concern is hooking up the brake lines and bleeding the brakes correctly. I think with the rear axle still in place, I'm less concerned about being underneath the trailer/boat, but I'll still place jack stands under the frame rails for safety. Any tips on this installation would be appreciated especially hooking up and bleeding the brakes. Is there a way to manually activate the brakes to "pump" them? I'm thinking of just getting a mityvac brake bleeder to do this as well.

06-20-2011, 02:20 PM
When I was checking out the brakes, I used a metal post about 6 ft. long as a lever to activate them. I used dock line tripled up several times to hook the bottom of the post to the "u" like bracket thing sticking down under the tongue (just behind the coupler). With the bottom hooked to the trailer, I pushed on the top to use it to push back on the front of the coupler and activate the brakes - had a lot of leverage. Don't know if that makes sense, and it wasn't easy but it worked.

06-20-2011, 09:23 PM
I used my vehicle. I would back up, set the emrgency brake, crack the bleeder valve, let air out and then close. Pulled vehicle forward, opened master cylinder and filled. Repeat again until air is out. You have to use chalks on wheels to do this. I found this to be the easiest way for me.

06-20-2011, 09:34 PM
Page 24 and 25 of this file shows the process to manually bleed the brakes.

06-21-2011, 01:58 PM
I'm going to have to bleed my brakes here pretty soon also, due to the reverse solenoid going out on the actuator. I saw this procedure and was curious if anyone had bled their brakes this way. I'm surious how difficult it is to depress that plunger they show in the figure?? Anyone know??

you da man
06-21-2011, 03:03 PM
I'm going to have to bleed my brakes here pretty soon also, due to the reverse solenoid going out on the actuator. I saw this procedure and was curious if anyone had bled their brakes this way. I'm surious how difficult it is to depress that plunger they show in the figure?? Anyone know??

All you need is a medium size flat tip screw driver and it gives you plenty of leverage. Bleeding the brakes is a piece of cake with 2 people. I wouldn't try replacing the axle alone. The axle weighs 90-95lbs and needs to be lifted in place. Two floor jacks make this job easy (one under the trailer rail for safety and the other to lift axle). Hope you have an impact gun too...cuts the time down. The brakelines are the only real issue because of the metal lines. You don't want to kink them. Have a pry bar to get the trailing arm off the spline. Aligning the the trailing arm onto the spline of the new axle is hit or miss as far as getting it at the right angle. Have a torque wrench as well to get everything back to specs. Takes me and my friend about an hour to change an axle now after doing it twice.

06-21-2011, 07:25 PM
YDM, thanks man. I figured since the instructions showed a screwdriver, it wasn't that bad. Sounds like a fun afternoon job... I'm hoping only about 3 beers... though they may have to be 24 ouncers.

06-21-2011, 08:20 PM
i used the screw driver to bleed as well.. you can use a hand pump bleeder as well to pull the the fluid thru the lines... i think the easiest method is the screw driver and a buddy at the caliper opening and closing the bleeder valve..


They will vibrate loose if you dont........ learned this the hard way.........

07-16-2011, 11:03 AM
Well I finally got time to replace the front axle on my tandem. It went better than I thought it would. I was surprised at how simply everything goes together, for some reason I was expecting a more complicated setup. I did it by myself as my normal helper was out of town.

For background, I didn't not have the same issue as others that initiated a replacement of the axle. Most will have the issue where the internals of the axle break and the trailing arm pivots up so that the tire is rubbing the fender. In my case, my belief is that the previous owner trailered tongue-low so that there was undue stress on the front axle, causing a permanent state of toe-out and negative camber. When I bought the boat last august, the insides of the front tires were almost bald, and cupped.

I had replaced the trailing arms on this same axle previously (in hopes that they were the reason for the toe-out and neg camber), so those slid off nicely because I had used anti-seize on the splines.

There are four bolts holding the axle to the trailer, two on each side. When I loosened them, it didn't feel like they were at 150lbs of torque (which is the spec), so I thought that was curious.

The brake lines came off easily, with very little spillage of brake fluid.

I loosened all four bolts and put the nylocs back on the ends of the bolts to hold everything. Then I removed the two bolts from one side, and set that end down on my creeper. Then I removed the two bolts from the other side and set that end down on a 4X4 block of wood. Then I just picked up that end, kicked the 4x4 out of the way and moved back to get the axle out from under the trailer. I positioned the new axle the same way, I put one end on my creeper and just lifted the other end and rolled it under the trailer. It worked pretty slick. Then I lifted one end all the way up to the frame rail and stuck the bolts in and threaded on the nylocs to hold it. Then did the same for the other end. After it was loosely bolted in position I then tighted them to spec.

Boatmate did a not-so-precise job of tacking on the brake line to the axle tube. I had to pop the brake line out of the brackets on the axle tube to reposition it so that it reached both ends of the axle appropriately. In the process one of the welded-on clips popped off (bad welding job), so I just used a SS hose clamp to hold it since its underneath I wasn't too concerned about how unsightly the clamp will be.

I then re-connected the brake lines, re-installed the trailing arms (150lbs torque), and re-installed the calipers (using loctite 242) and used spray paint to touch up the axle from where it was not packed appropriately for shipping, and also because Boatmate painted the axle after installing the brake line, so when I had to move the brake line, it revealed bare metal. For bleeding the brake lines, I used a Mityvac hand pump which worked pretty well. The only PITA part was needing to frequently refill the master cylinder because it doesn't hold much fluid. I pulled new fluid through all of the lines so it took a while because of the need to stop and refill the MC.

I haven't pulled it yet with the new axle, but visually I can see the improvement in the toe and camber. In total it took me about 4 hours including blocking up the trailer.

you da man
07-16-2011, 01:05 PM
Agree with the brakeline welds and routing on the axle. It is a "simple" big job, just two people make it easier. The only thing that makes it feel like "work" is because your on your back in cramped quarters.