Trailer coupler alignment gage

[dave powelson]

This is a simple but accurate gage, that one man--not two, can use to check alignment of the coupler to the frame points, and especially--alignment of the coupler centerline to the axle spring mounts.

It's too easy to be off with a string or tape and two guys crawling around--That's how i ustah do it, too.

It will positively, accurately show relation of the coupler centerline to what ever one's measuring....if one's interested in building a trailer frame that's square and centered on the coupler centerline; or having a trailer track straight.

http://i300.photobucket.com/albums/nn33/davepowelson/trailer%20coupler%20align%20gage/P4260003120.jpg

http://i300.photobucket.com/albums/nn33/davepowelson/trailer%20coupler%20align%20gage/P4260005100.jpg

By using different pipe sizes, one can accommodate various sizes of balls and their shanks, as shown in the pics.

Setup:

1-add blocking, etc. to get the dummy ball into the coupler, lock coupler. Adjust the nut on the dummy ball shank for snug contact uP into the coupler--so the pipe doesn't move around while tramming measurements.

2-using the 3-way post level--tap the pipe around until BOTH horizontals read LEVEL.....and measure away!

[Oldtimer]

OK, looks good. I always have built trailers upside down to simplify welding. I just set the whole axle assembly on the frame and use a clamp on magnet on my tape measure and measure and measure to the center of the tip of the hitch. I only use Bulldog hitches and the ball clamp comes to a point so it is really easy.

[Sandy]

Yeh, looks good. I like the snap swivel idea.

[dave powelson]

OK, looks good. I always have built trailers upside down to simplify welding. I just set the whole axle assembly on the frame and use a clamp on magnet on my tape measure and measure and measure to the center of the tip of the hitch. I only use Bulldog hitches and the ball clamp comes to a point so it is really easy.


This allows tramming from the actual centerline of the ball to the axle, frame components---after the trailer has been built, like axle change-outs, frame repairs, etc. The tape can be 1" off the deck or 3ft.--with the right length of pipe or blocking. The pipe/ball assortment lets one do this for big and little trailers, modular homes, etc.

IMHO--it just isn't 'real easy' to flip a completed trailer uPside Down--in order to set things square.

[olddad]

2 strips of 1" banding work great as well. You usually know what your distance from axle centerline to ball is supposed to be. Just clamp the 2 pieces of banding together and drill holes for your measuring locations, then put rivets in them without cutting the excess off. You now have your measuring device with pins in them for locating in the axle mounting brackets and one for the ball receiver. Two strips of banding and three rivets later you have an accurate layout tool that opens like a V and is easily stored on the wall.

[dave powelson]

Oldad: You've got your ways and I've got mine of doing things.
Flipping the trailer upside down, as you posted above, really isn't a option, especially in a repair scenario (replacing an axle/coupler).
What I've show can readily tram for centers, frame square dim's., etc.
Depicted below, can be done easily, accurately---by ONE man--not two.
Works on 60' double-wides, to lettle trailers like below; in the field or the shop.]

Oldad sez: "You usually know what your distance from axle centerline to ball is supposed to be."

???? Is there some sort of master book, that tells us that, for every trailer made?
Factory and home built?

I never know what 'it's supposed to be' and could care less.
This gauge tells you what it actually is--and can be easily measured, along with tramming the axle outer spindle centerlines for square, tramming the frame to the centerline, the frame relative to the outer spindle centerlines, etc.

A big plus, in my pea-brain, is using a dummy ball, locked into the coupler, that absolutely, positively--finds the actual, ball centerline DATUM of the coupler.
(I just have a thing about DATUMS.)
There is NO guessing.....and this tramming happens very quickly.

Below is 'why' this trailer's coupler was replaced with new. Is anybody on this forum going to
claim this as their handy work?

http://weldingweb.com/attachment.php?attachmentid=22169&stc=1&d=1217120339

Below is the dummy ball setup, in the new coupler. The 2 way magnetic post level
is set for level in 2 planes, then the measuring tape is hooked into the little spring
clip:
http://weldingweb.com/attachment.php?attachmentid=22170&stc=1&d=1217120380

Below is a magnetic square with small piece of match cut angle iron, extending out
far enough to be measured with the tramming tape:

http://weldingweb.com/attachment.php?attachmentid=22171&stc=1&d=1217120507

Below is a perspective view of the tape being trammed on one side:

http://weldingweb.com/attachment.php?attachmentid=22172&stc=1&d=1217120533

Below is the customer posing with the tramming tape:


http://weldingweb.com/attachment.php?attachmentid=22173&stc=1&d=1217120660

[olddad]

Oldad: You've got your ways and I've got mine of doing things.
Flipping the trailer upside down, as you posted above, really isn't a option, especially in a repair scenario (replacing an axle/coupler)
Listen jack-***, I'm not the one that mentioned flipping the trailer !! I can see the possibility for 3/8 off with your method quite easily, while that might be close it's still a lot of wasted tire heat and wear. And furthermore, I said absolutely nothing derogitory about your method. I only pointed out a different tool, one that does not err. I'll leave it at that, you'll be glad to note that I'm now done with your damn thread.

[dave powelson]

Listen jack-***, I'm not the one that mentioned flipping the trailer !! I can see the possibility for 3/8 off with your method quite easily, while that might be close it's still a lot of wasted tire heat and wear. And furthermore, I said absolutely nothing derogitory about your method. I only pointed out a different tool, one that does not err. I'll leave it at that, you'll be glad to note that I'm now done with your damn thread.

Whoa! I'm sorry, I got confused between Olddad and Oldtimer. My mistake.

3/8" off.......well, that's debatable--seeing as how you've never used this and
may not fathom the methodology used.

For whatever, it's worth--there's 50 trailers 'out there', that track very, very well,
with no tire scrubbing or crabbing.

At this point, the constructive purpose of this thread has ended and it will
regress into diatribes, name-calling, and opinionated, unsubstantiated drivel....
...which is all too common in this forum.

[Craig in Denver]

WAIT!! Don't go away mad!! :waving:

I'm confused. It looks like the axle extension depends on the rotation of the wheel? If it's fastened to a lug nut, there are 360* of possible positions. :confused:

[Oldiron2]

If I were stuck in the desert and had to use my battery for power and bailing wire for rod, with native mud and urine for a sun-baked coating, I might be proud of that original repair job* ....IFF** it got me and my newly-dug 50# box of gold nuggets home safely. Otherwise.....

* the one shown in the first picture.
**where IFF means "if and only if ".

[duaneb55]

Oldtimer, olddad and now Oldiron2! Now I'm confused.:dizzy:

[dave powelson]

WAIT!! Don't go away mad!! :waving:

I'm confused. It looks like the axle extension depends on the rotation of the wheel? If it's fastened to a lug nut, there are 360* of possible positions. :confused:

Craig-

Explained in the previous post:

"Below is a magnetic square with small piece of match cut angle iron, extending out
far enough to be measured with the tramming tape."

Often, the wheels are off the trailer, providing more ready access to the hubs/spindles, so no extension business is needed.

IOW:

1-Nothing is connected to any lug nuts. Tire pressure is equalized. (Warned this old-time customer that the tires are trash.) A strong magnetic square on the buddy bearing hub OD, holds the angle iron piece. The angle iron is parallel to the machined OD of the buddy bearing.
The angle piece is leveled, then, in this case, a square on the floor lined up the angle iron edge to the centerline of the grease zerk, shown in pic below
with red line.
Ditto is done with the other side.

http://weldingweb.com/attachment.php?attachmentid=22179&stc=1&d=1217135111

[duaneb55]

Dave,

I never would have thought that repair would lasted this long!:laugh::laugh:

With all due respect for your ingenuity I'm missing something here. You're replacing the coupler not the axle or any suspension part so why the need for all this measuring? The coupler being used is designed to be bolted on which leaves no way for angular adjustment from that of the tongue it's bolted to - or in your case welded. So if there were a side to side variance found would you bend the tongue to correct it? I'm confused.:confused:

[dave powelson]

Dave,

With all due respect for your ingenuity I'm missing something here. You're replacing the coupler not the axle or any suspension part so why the need for all this measuring? The coupler being used is designed to be bolted on which leaves no way for angular adjustment from that of the tongue it's bolted to - or in your case welded. So if there were a side to side variance found would you bend the tongue to correct it? I'm confused.:confused:


The coupler being used is designed to be bolted on which leaves no way for angular adjustment from that of the tongue it's bolted to - or in your case welded

1-There's a bunch of slop on the fit of those couplers to the tongue tube--like a 1/4".
Real easy to get it cocked.

2-The old coupler had been severely jacknifed, torn part way off, then scab-welded. I was also concerned about that the tongue tube, might be twisted.

3-Setting the coupler centerline to the spindle centerlines--means the trailer will track straight
regardless of how the trailer was originally made or subsequent damage. The alignment checking shown here, took all of around 10 minutes.

4-Customer had just bought this boat and its trailer. Now is the time to check tracking.


'So if there were a side to side variance found would you bend the tongue to correct it?'


This tongue tube was only 1/8" wall. No I wouldn't bend it. Depending on why and how much
then either slit, bend at the slit, butt/bevel weld, then doubler plate (with only longitudinal welds--not transverse, like is often shown on this forum).....or install a new tube.

[duaneb55]

The coupler being used is designed to be bolted on which leaves no way for angular adjustment from that of the tongue it's bolted to - or in your case welded

1-There's a bunch of slop on the fit of those couplers to the tongue tube--like a 1/4".
Real easy to get it cocked.

2-The old coupler had been severely jacknifed, torn part way off, then scab-welded. I was also concerned about that the tongue tube, might be twisted.

3-Setting the coupler centerline to the spindle centerlines--means the trailer will track straight
regardless of how the trailer was originally made or subsequent damage. The alignment checking shown here, took all of around 10 minutes.

4-Customer had just bought this boat and its trailer. Now is the time to check tracking.


'So if there were a side to side variance found would you bend the tongue to correct it?'


This tongue tube was only 1/8" wall. No I wouldn't bend it. Depending on why and how much
then either slit, bend at the slit, butt/bevel weld, then doubler plate (with only longitudinal welds--not transverse, like is often shown on this forum).....or install a new tube.

OK, but kinda tough on the paint job don't you think?:drinkup::sleeping:

[goodoleboy]

Though I dont know much about welding thank you for posting pics as it explains alot of ywhat your talking about..

[Fat Bastard]

Great idea Dave
I have used variants of this for years.

Many times axles get squared to the frame but never check to the pulling point. The only point that matters.

If the wheels are not true to the hitch then it will not pull efficiently.


Thanks for the post.

TJ

[dave powelson]

Great idea Dave
I have used variants of this for years.

Many times axles get squared to the frame but never check to the pulling point. The only point that matters.

If the wheels are not true to the hitch then it will not pull efficiently.


Thanks for the post.

TJ

After screwing around with tapes and 2 of us, crawling around in the dirt, on field or shop jobs, trying to set axles true to centerline--I came up with this gage in desparation.
Made life easier and less worrisome.
Side benefit is being able to tram the trailer frame corners, etc. to centerline. Many trailer frames including factory built, including Wells Cargo--aren't built square, BTW.

[Rojodiablo]

I can see where a trailer that is surely not square, nor symmetrical would give a repairman fits. Thanks for this easy way to check alignment.

[tanglediver]

I can see where a trailer that is surely not square, nor symmetrical would give a repairman fits. Thanks for this easy way to check alignment.

Dave's tram set is ingenious. We see trailers constantly built with one thing or another out of true. For the most part, things will still function nominally, but occassionally, a box will be mounted on a frame that causes tire clearance issues with spring or side wall flex that only serve to leave us pulling hair and teeth out trying to understand where the error has occurred. Trailer owners never want to hear that the lovely RV they just bought with low miles on it has a crookedly mounted box causing tire rubbing.

[duaneb55]

Side benefit is being able to tram the trailer frame corners, etc. to centerline. Many trailer frames including factory built, including Wells Cargo--aren't built square, BTW.

And if you don't think that's true, come put a tape to this boat trailer we're modifying! I don't have one of Dave's rigs but the old 'two-man' method proved it just the same.:(