The Boating Forum - Aligning your trailer axles.

THE HULL TRUTH is the world's largest FREE network for the discussion of Boating & Fishing. Whether you're researching a new boat, or are a seasoned Captain, you'll find The Hull Truth Boating & Fishing Message Forum contains a wealth of information from Boaters and Sportfishermen around the world.




View Full Version : Aligning your trailer axles.


mikeloew
05-28-2008, 08:21 PM
I am on the road right now and I finally have my boat off the trailer. I have tried to measure my axles from the frame members but I don't trust the cross members. has anyone ever used a straight edge across the sidewalls of the tires, if all four points of the sidewalls are touching the straight edge shouldn't the exles be square? I realize that does not mean the axles will be square to the frame but wouldn't that be really close? When I put a straight edge across my duel exle it looks like one exle is cocked about a 1/2''


jenkinsph
05-28-2008, 10:17 PM
I would measure from the center of the ball coupler to the front inside edge of each tire. Make sure the trailer is on level
ground when you do this. I agree the axles should appear to be parallel with the yardstick test but the above method is
more likely to show you where the problem is.



Steve

bamaboy473
05-29-2008, 05:37 AM
with the boat off the trailer, pull the trailer down the road and see whether it rides directly behind the vehicle or whether it veers to one side. Then check the tread on all the tires and see if there's scuffing. If it rides behind the tow vehicle and if there's no scuffing, the axles are square.


bamaboy473
05-29-2008, 05:42 AM
I measured my axle with string. Wrapped the loop around the hitch ball, knotted it there, and ran string 25' parallel then put magic marker spots on the strings (while they were still parallel) somewhere close to the axles. Then I ran a line to left and right edges of the axles and measured distance from spot to axle.
It worked for me and saved trying to wrestle with a tape measure. :thumbsup:

jeffnick
05-29-2008, 08:42 AM
Why would you do anything with the boat OFF the trailer? Aren't we more concerned about alignment with the boat ON the trailer?

bamaboy473
05-29-2008, 02:32 PM
Maybe I'm missing something, but the boat (or any other payload) doesn't affect the trailer's tracking. You can't very well make adjustments with any payload on board anyhow, can you?

billinstuart
05-29-2008, 02:53 PM
Race cars all over are aligned with parallel strings. If the strings are parallel with the centerline of the trailer, measure from the strings to the tires/wheels. Any toe error or tracking error will show up. Spin the wheels to make sure they spin true. Loading the trailer shouldn't change toe on straight axle trailers. Your straightedge does essentially the same thing. This ain't rocket surgery, and you've got the idea down pat. Sighting down the side when the toe is correct, you can visually detect camber differences, but tha'ts another class.

PF-88
05-29-2008, 04:43 PM
My father used to have a welding business and build trailers on order, he always alinged the axels by measuring from the center of the ball coupler to the center of the end of the axel spindels. If the measure is exactely the same both sides he said the trailer will allways pull straight. I've fixed a couple of trailers myself using this method.

rwidman
05-29-2008, 05:35 PM
bamaboy473 - 5/29/2008 4:32 PM
You can't very well make adjustments with any payload on board anyhow, can you?

Of course you can. That's what jacks and jackstands are for.

I replaced all my brakes and moved my axles with a 6,000lb boat on a 1,200lb trailer. It would have been easier without the boat but the advantage was having the trailer at home with all my tools (including air tools) available.

To the OP:
I don't know why you don't trust your crossmembers, bot measure corner to corner where they meet the frame. If the measurements are the same, the crossmembers are perpendicular to the frame.

Best way to align the axles once you're sure the crossmembers are perpendicular - Cut a piece of 2X4 stock to the distance you want between the axle and a crossmember. Loosen each end of the axle, place the 2X4 between the axle and the crossmember on one side and use a mallet to drive the axle tight against the 2X4. Tighten the mounting hardware, then repeat on the other side.

Cut another piece of 2X4 to align the axles to each other.

rwidman
05-29-2008, 05:38 PM
mikeloew - 5/28/2008 10:21 PM
....... has anyone ever used a straight edge across the sidewalls of the tires, if all four points of the sidewalls are touching the straight edge shouldn't the exles be square? ........

The tires can easily be different widths (slightly) so this would not be an accurate measurement. In theory, you could do this with the wheels (minus the tires) but that would be way too much trouble.

billinstuart
05-29-2008, 06:06 PM
Spindles are often not square with the axle itself. The string method addresses the real issue..what the tires and wheels are doing relative to the line of travel. Up to 1/8" toe in/out should be ok for a trailer. Strings are accurate to 1/32" easily.

nlkent
05-29-2008, 07:14 PM
I would be careful using a string as they can stretch quite a bit depending on how hard you pull it. I wire string would be better. Less give. I would go the tape measure route and not the string route.

rwidman
05-29-2008, 08:35 PM
billinstuart - 5/29/2008 8:06 PM

Spindles are often not square with the axle itself. The string method addresses the real issue..what the tires and wheels are doing relative to the line of travel. Up to 1/8" toe in/out should be ok for a trailer. Strings are accurate to 1/32" easily.

If that were the case, you would have real problems because the spindle could be off in several directions (forward, back, up, down). A replacement axle would be the cure.



Search Engine Friendly URLs by vBSEO 3.2.0