Do I have a trailer bunk problem?

[RoryWainer]

When working on my boat the other day I noticed that I could see daylight through a gap between the hull and one of the inner bunks on one side, the other side seems okay. Pictures attached.



It just looks wrong to me but I could be getting paranoid about trailer support.

I can see an adjustment nut/bolt, but I don't want to fiddle with things without some better informed opinions. Any ideas?

 

[fridaysoff]

Rory,
I think that it is the bunk itself that changes shape. I have noticed it on my 195CC several times during a season. Check the same areas in a month and see if it is the same. Wood naturally bends, warps, and changes shape with different amounts of moisture content. The bunks are long and the longer a board is the more it will bend out of shape. I hope that is the issue with yours.
John D.

 

[mrgreencms]

Rory. I agree with John, but I am going to check my support on my 195CC. I was underneath mine last week stapling some loose carpet (that is what I call it) to the bottom side of the board and did not notice anything that is suspect. However, I did notice that the support boards are about one-inch short from the back of the transom, the boat extends about one-inch over the supports. I do not know if this is an issue or not, and I have been thinking about it for a week and I probably need some advice from the veteran Triumph owners.
Dave

 

[Dave LeGear]

Yes I would ensure that the hull is supported and has bunks located "past" the stern

Now the fastest way I know of to correct this, is to move the wench stand further forward on the trailer, and then go reload the boat back on the trailer and adjust as needed. A good project for a weekday down at the ramp and not the weekend naturally

You can also work with the bunk spacing at the same time and do yourself a favor and start spraying on some penetrating oil on all of those bolts and nuts a few days before you try and move them around.

A propane torch (the blue wrench ) may also need to be in the truck along with your other tools needed for the job. Some of those may be a little tough to break free, and is the perfect time to use a longer breaker bar and 6 sided socket for such work.

Just be careful and do not put too much "grunt" on them or you could round a few of them off... A great the time to use a combination of both "Force and Fineness" when trying to break them free enough to adjust them without (hate when that happens) breaking them or rounding them off. This is why I recommend the use of 6 sided socket

 

[Harper]

Rory, I don't think it's much of a problem. My take on it is slightly different than those posted so far. The daylight shown in pictures 1,2,6,&7 look like a slight waviness in the hull to me, rather than the bunk. Now the tilt in the bunk as viewed from the rear in pictures 3,4,5,8,9,&10 is a result of driving the boat onto the trailer during recovery. The bunks are each supported at just two points, and the weight of the boat moving onto the bunks spreads them slightly, causing them to deflect downward and outward, and since they are on a pivoting bracket (those brackets do swivel on the mounting bolts, quite easily, actually) as they are forced out and down, they are also tilted slightly inward in relation to the hull. Now my question about this would be, can we assume that this tilting is okay? I don't know the answer to that for sure, but I've not worried about it, since there still seems to be adequate support to me. The only way I can see that it could be corrected is to add a third cross member on the trailer, between the existing cross members, with a third set of brackets supporting the bunks. This would prevent them from being pushed down and outward, yet they could still swivel enough to allow them to conform to the deadrise in the hull. Or you could do what Push&Pull did and build a whole new trailer.

 

[mrgreencms]

Mike
Good information. Qeustion. Is there a picture of what you are describing and is there a picture of Push&Pull's trailer?

 

[Harper]

Dave check out the last three pictures above, in Rory's post. Since the attaching brackets support the bunks near each end of the bunk, the weight of the boat causes the bunks to deflect not only downward, but also outward (since the hull doesn't have a horizontal cross section, it's a "v", not flat, and the deadrise is higher closer to the bow than the stern). This outward deflection, in particular, causes the tilting of the bunk in relation to the hull as it appears at the stern. You can go to the center of the bunk on your trailer, and if the bunk is still wet (slippery enough) you can actually push that bunk inward with your foot, and the tilt is gone. Actually, the extra cross member is not the only solution; all that would be needed would be a connecting piece between the bunks in the middle to keep them from spreading as they deflect under the weight of the boat.


You can find Bill's trailer here http://www.performanceoutdoors.net/...5373-210-cc-trailer-bunks-sagging-trailer.jpg It a purty, custom thang.

Dave, (mrgreencms), I just re-read these posts and realized the Dave the Putershark was answering your post...as he said you need to move the winch stand forward, and get that stern up on the bunks. If that makes your tongue weight too heavy, then you'll need to move the tandem axles forward, too. Measure carefully when moving axles. I had to move mine almost 7" forward, .....had 700 lbs on the tongue to start, and now have 300 lbs.

 

[Push&Pull]

Rory,

Your main issue is the bunk not supporting the transom. More than likely the aft end of the bunk which is not supporting the transom is therefore pressing up on the hull bottom causing the hull to deform. Once the bunk is supporting the transom the deformity should relax back to normal. As stated in the posts above, just move the winch stand forward while the boat is still on the trailer and simply winch the boat forward to the new position. (then as Harper said, recheck your tongue weight)

BTW: Credit where credit is due. The link to the trailer in Harper's post is actually a pic of Osprey Vic's trailer. A very nice trailer, I might add. You can see mine in the pics on my profile in the "At the ramp" album. However, due to the Aluminum motor bracket on my boat, my trailer support is somewhat different. My basic advice on trailer support for roplene hulls is;.....use plenty...... and of adequate structural integrity so that the supports themselves do not flex.

Oh, one more thing.........get a better camera or take photography lessons........those pics are terrible. LOL

 

[RoryWainer]

I did some more work on the boat today, fitting trim tabs, etc and when standing back from the rear of the boat I noticed that there is nothing wrong with the hull or trailer...just the boat is not square on the trailer. The stern is skewed more to one side.

I recall that the last time I came in they sent a different tractor driver than usual and he put the trailer too far in the water, and the current was ripping even more than usual. For whatever reason the boat just didn't straighten itself up as it came out of the water. No wonder it isn't sitting on the bunks correctly, it 3" too far to one side.

Better take Friday off and straighten it out.