Hull hitting trailer axle?

[JC6275]

Have you checked the leafs in the spring packs? I doubt they are broke but I can't imagine any other reason you would be hitting.

 

[GiddYupJoe]

The trailer just came back from the shop a few weeks ago. Re packed the bearings and checked everything else. He said everything looked great. He was the one that pointed out the rubs on the axel. I will check tomorrow but I doubt it.

I checked tonight and I have about 1 1/2" clearance between the hull and the forward axel. I will get exact when it's light out tomorrow.

 

[Boat Crazy]

Measurements on my AR240 on MFI trailer with boat hooked up to truck in a slightly downward driveway (bow forward on slope).
Boat hull center to front axle (2 and 3/4 inches)
Boat hull center to rear axle ( 3 and 3/4 inches)
Axle to boat difference most likely due to sloped driveway with boat mounted on trailer.
Distance of bunks from one bunk to the other at the top of bunk (8 and 1/2 inches)

 

[Boat Crazy]

Just looked at mine again. My hull on the front axle sits about 1/4 inch (ABOVE) the lower part of the bunk at the axle. My guess with the axle on flat level ground it would be even with the lower slant of the bunks.

 

[GiddYupJoe]

After further inspection this morning I noticed two separate issues. The keel hitting the axel when loading/unloading AND it looks like the axel is hitting the hull during transport.

As to @Boat Crazy findings... We are way off on measurements??? Maybe @Ronnie could also do a quick check to use as a third comparison. I have roughly 1 1/2" gap.



For the second issue, check this out! The bunks have a curved indent where the axel is coming up and hitting the hull and bunks. You can also see some tub spots on the hull directly above the front axel.








This last picture show the U bolts on the axel coming up and tubbing the frame.



I am thinking that the issue of the axel hitting during transportation could be chalked up to the curb at the end I my driveway. When I back in at an angle there is a lot of play between the front and rear axel. At any point going over they curb there could be 8" difference between front and rear.


When trail wring I do not notice anything wrong at all. Rides smooth, dosnt move around. Very little shifting.

Thanks for the help.

 

[txav8r]

Hmm, someone mentioned springs, and that might be a player. But your bunks may be dry rotted and just letting the boat sag way too much as well as letting the pressure of the boat push the bunks down into the axle. Something isn't right with it that close however it appears, if there is that much difference between @Boat Crazy trailer setup and yours.

 

[JC6275]

Are the bunk mounting brackets adjustable on those TRAILERS? If they are it's possible they have moved from the original location. If they have slots for adjustment where they are mounted to the trailer they may be the culprit.

 

[GiddYupJoe]

@JC6275 I will look and see if they are adjustable. While I am under there, what should I be looking for in the springs as you mentioned earlier? Nothing seemed to look out of place. But not sure what to specifically look for.

 

[JC6275]

Look at the spring packs, close to where they go over the axles on both sides, look for broken leafs, you may have to look close, follow each leaf all the way from one end to the other. sometimes you will see a small gap between where a leaf Is busted. With you saying the curb at your driveway is pretty high this may be what has happend

 

[JC6275]

Your trailer looks pretty clean, so look for spots of rust on the springs as that can be a indicator of a spot where a leaf is broken.

 

[txav8r]

The mfi trailers are hard weld supports and no adjustment on my '08 mfi whatsoever. The only adjustment would be lateral positioning of the bunks if you replaced them with new boards. And the springs as I think about it, shouldn't affect the ration of height between the bunks and frame. The springs affect the height of the frame to the ground, as the shock absorbing system for the trailer on the road. You could have a broken steel support weld possibly, or broken bunk, or just rotten bunks that allow way too much sag. That said, many of us installed the UBB's (ultimate bunk boards made of HDPE) that were much more flexible and actually sagged a tad more than a wood bunk. There has been plenty of discussion and observation over the years regarding these trailers, their design, function, and weaknesses. I have not seen this issue before or read about it. And in previous discussions about the amount of support needed/given with the UBB's vs carpeted wood, we have always presented that mfi says the steel supports carry the load, the bunks only disperse it a small amount, that the bunks are just there to allow you to load/unload and align the boat on the trailer. Has anyone moved the bow stop post on this trailer? That could have an instant impact as to how the boat sits/loads on the trailer too. If it were too far forward, more weight on the hitch, more boat weight on the forward part of the bunks, more sag there. Something isn't right here, you can call mfi and get them involved as well. Here is some contact info...
Metal Fabrication Inc.
604 Creasman Drive
Winchester, Tennessee 37398
Email: contact@mfitrailers.com
Phone:
(800) 606-9100
(931) 962-0025
Fax:
(931) 962-0026

 

[Boat Crazy]

Hopefully these pictures may help in locating the difference and why.

 

[GiddYupJoe]

Thanks for all the help, insight and troubleshooting. I am going to chalk this up to rotted bunks. After further inspection they look pretty bad all around. After I get the boat back in the slip after vacation I will get on it and see what difference it makes. Needs to be done anyway. If that does not produce different results I will continue troubleshooting.



Not sure if you can tell in the pic but the mount is embedded in the wood. The bottom of the mount is almost flus with the wood. This should not be the case.

 

[JC6275]

That would be the problem, I'm betting on it... Just like @txav8r said.. Good info Mel!!!!

 

[txav8r]

Yeah, your crushing the bunk. Probably want to replace the asap. Good that your narrowing this down.

 

[txav8r]

At the very least, you could get a steel plate that spreads the load over more of the bunk to put in as a spacer between the bunk and the mount, but I am betting your bolts are not holding well either and that the bunk is pretty rotten. Trailering may be another point of wear and damage until you get the separation between the boat and frame it should have.

 

[GiddYupJoe]

Let's hope for the best getting down to Norris. Unfortunately I can't get the boat off the trailer prior to leaving next Saturday. At least now I can keep an eye on it. Thanks again fellas.

 

[Ronnie]

Sorry late to the party, I will post additional reference measurements when i get home.

 

[Bruce]

If replacing the bunks does not solve the problem you might try doubling up the wood on the bunks. That would elevate the boat a little.

 

[txav8r]

It would elevate it 1.5". It would also change the bow stop post height to bow stop and require post height adjustment possibly too.