Changing trailer height

[skyking897]

My boat sat real high on the trailer and made launching/loading in shallower water a real problem. Had to back in soooo far my truck was in the water too. Anyway, I flipped the axle to sit on top of the leaf springs (dropped about 4 1/2") and now have almost no ground clearance and the trailer axle is very close to the keel. I'm afraid it will hit if the trailer bounces while driving. My question, how do I raise it about 1 1/2"-2"? I thought about new leaf springs but after measuring new ones (the arch), I'm not sure that's the way to go. I remember back in high school we used to put longer shackles on the rear of the leaf springs to raise the back end of our cars. Is this a viable solution for a boat trailer? I thought abought 2" longer shackles. I've seen some on ebay for sale. Any thoughts, good or bad? I'd feel better if it was midway between these two levels.

 

[scoutboater]

Re: Changing trailer height

Hey skyking,

You know what the first thing you need to do is.... We need to see some pics.

After that, I would be looking at how the boat itself sits on the trailer. Is the boat really high above the frame of the trailer? If so, can you move/lower the bunks to make the boat sit a little lower? That would be my first option.

Lastly, I've seen a lot of 4x4s develop some pretty bad handling because of those longer shackles. Granted, they were homemade and about 5 or 6 inches long, but still.

-sb

 

[boaterinsd]

Re: Changing trailer height

ya, pics would help. I know my roller bunks can be raised or lowered. What type system does yours have?

 

[skyking897]

Re: Changing trailer height

It is a Trailmaster bunk trailer and the bunks are non adjustable. It is the same year as the boat so I'm assuming it is original to the boat. The cross members are "V" shaped and the boat sits low in the frame on the bunks. No adjusting going to happen there. I'll try to get some pics later today.

On edit: I have some pics posted in the Sylvan boats section, under "bought sylvan offshore"

 

[jeeperman]

Re: Changing trailer height

those pics you posted in jan 2011 must be after the axle "flip".

which i hope you meant you moved the axle to above the leaf springs?

How much space do you now have between the top of axle and the frame member?

How much space do you have from top of axle to keel?

 

[Tahorover]

Re: Changing trailer height

I had the same problem and just added a 1.5" block under the bunk mount. My bunks were 2x6 and I unbolted them and blocked them up with a 2x6.

 

[skyking897]

Re: Changing trailer height

jeeperman..... there is 2" between the trailer frame and axle and only 1 1/2" between the axle and keel (see my concern). And yes those photos were from last fall when I did the flip (moved axle above the springs).

 

[skyking897]

Re: Changing trailer height

Tahorover..... I could raise the bunks doing this but then the keel will not be touching the rollers. Don't know if that is a problem or not, but the kell rollers are not adjustable as well as the bunks.

 

[craveman85]

Re: Changing trailer height

a 2inch longer shackle will raise the trailer 1 inch . maybe you could put the axle back under and try a different tire size

 

[craveman85]

Re: Changing trailer height

or make an extension for when you launch your boat.

 

[Silver Eagle]

Re: Changing trailer height

How much room between the top of the wheel and the bottom of the fender. Maybe you could just get a larger size tire and wheel.

 

[Frank Acampora]

Re: Changing trailer height

If the center bolt is long enough, how about adding an extra leaf or two to the springs? How about higher load capacity springs? new ones are not all that expensive.

 

[skyking897]

Re: Changing trailer height

craveman.....I don't understand your statementI don't see why a 2" longer shackle won't raise the trailer the full 2", please explain this to me.

 

[DuckHunterJon]

Re: Changing trailer height

The best way I can see would be with re arched springs. Adding leafs won't do any good if the axle is above the spring pack. Larger tires isn't going to move the axle away from the keel. Shackles are a quick and easy way to change the height, but as others have mentioned, they can cause sway problems if not done right.

You mentioned you looked at new springs - I'm assuming you were looking at some off the shelf. Go to a spring shop and ask them what they can do for your springs or new custom ones. Good luck with it.

 

[jeeperman]

Re: Changing trailer height

craveman.....I don't understand your statementI don't see why a 2" longer shackle won't raise the trailer the full 2", please explain this to me.

The shackle lifts only one end of the spring.
But your axle is at the middle part of your spring which only moves half as much.

 

[skyking897]

Re: Changing trailer height

thanks jeeperman, it makes sense now.
I'm taking a spring to the local spring shop tomorrow and will post their recommendations later.
BTW... the trailer had 14" wheels when I bought it and I have 15" wheels off my utility trailer on it at the moment. There is only about 1" clearance between tire and fender at the moment. the 14's are about 1 1/2" shorter.

 

[skyking897]

Re: Changing trailer height

Ok, the guy at the spring shop threw out a lot of suggestions, but no real recomendations. In no particular order here is what he said. 1) new, heavier springs, but will be a very harsh ride, already have springs rated @ #3500. 2) longer shackles will raise it but.... 3) add a leaf to the existing springs and re-arching them should give me the height I'm looking for. 4)He could do what ever I wanted but it was my decision to make.

I'm thinkin I'll go with #3 and hope the ride is not too harsh because it rides real nice over the rough roads, no excessive bouncing or swaying.

 

[jeeperman]

Re: Changing trailer height

How are the front and rear spring brackets attached to the frame?
If it were me, I would look at putting spacers in between the frame and the existing spring brackets.

 

[skyking897]

Re: Changing trailer height

Spring mounting brackets are welded to the "C" channel frame.

 

[fibersport]

Re: Changing trailer height

How about a drop axle? That would keep the axle under the spring but lower the whole trailer and keep the same ride. Not sure how much you want to spend on this though.