This Old Trailer: Installation of a Trailer Coupler
Trailer Coupler Installation Episode of This Old Trailer
Today on This Old Trailer we are going to install a brand new coupler using part number 2836AT from Master Lock. This is going to be a three inch wide coupler on it and in between here is going to be three inches wide and it is going to use a two inch ball. The first steps involved are to remove the old coupler. It has been on there for awhile. It is rusted so take a couple of wrenches to it and maybe we will get lucky and we will actually break the bolts and get it to come loose that way. This little stand right here got bent back, probably pinching the coupler, so we are going to take that one apart too. Obviously this is rusted in place so we are going to have to persuade it off. 00:59
We will put our coupler on for a test fit. Usually the holes are not going to line up because the manufacturers have their own tolerances. We will take a look and see what happens. We have got one right here, this one will match up but we have too much vertical play so we are going to set it down and if we push it back we are too close to the original hole to drill out so it looks like the only other option is to take off about one inch of the tongue so we can scoot it back far enough and we can actually get into some fresh steel and drill and install our bolts. 01:40
Do a quick test fit. You have got plenty of fresh steel to go into now. Clamp it into place and mark and drill the holes out and install the hardware. It is a good idea to run the bit all the way through to make sure you have a straight line going all the way across. Install the bolts. Go in from one side to the other. Put on a lock washer and nut and leave it loose for now. Going towards the front of the coupler we are going to use two separate bolts. It will be easier to do on this one than the back one. If you remember the steel is kind of pulled to the inside, a little crushed. We are going to use the bolts to pull the steel back to the coupler. With our hardware installed take off the clamp and we can start tightening down everything. 02:48
Starting with the back we are just going to tighten it up. We want to tighten it up tight but we do not want to go so far as to start crushing the coupler and the tongue of the trailer. That was one solid assembly once again. Next we will reinstall the safety chains. We are going to use the originals but we are going to use brand new hardware and we are going to use a 3/ 8 bolt, that is grade five, and we are going to use a flange nut on the other side. That will get a good grip on the chain itself on the inside of the coupler. This is just one way of doing it. Certain states have different laws in how you attach safety chains. I know some states you can use one bolt going all the way through and some have to have two separate attaching points like we are going to do. We have got our safety chains reinstalled so those are good. The coupler is tightened down and we are going to leave the stand off because this coupler already has a jack that mounts on to the side. There you have it for our coupler install part number 2836AT from Master Lock.
Ed H.
1/26/2014
Would it be better to use 4 grade 8 bolts , I see you used 2 grade 5 and didnt say what the rear bolts were .....thanks , ed
Patrick B.
2/5/2014
All of the bolts we keep on hand in the shops are Grade 5 or better, because that is what hitches call for for their installation. Since this particular coupler is a 3,500 pound max, the hardware will not be taxed all that much. The tongue was enclosed tube, so a single bolt through the rear hole is easier, and again is adequate for the weights capacity in this case. If working with a channel tongue one bolt per hole is easily attached and spreads the load over more bolts.
Mike S.
10/19/2021
I am shortening the tongue on my, way to long, boat trailer and wondering how to determine the minimum tongue length. With a boat the turning radius, (horizontal axis around the ball) should not be to critical but I'm wondering about the vertical axis and distance to say the winch or front of the boat. What is a recommended length from the ball center to the closest vertical obtrusion, winch or boat?