# changing tire on trailer with boat on trailer



## johnnyandjebus (Sep 15, 2009)

Hello all
The tires on my trailer are old and need to be replaced. One in particular is really bad, a bulge on the inside side wall. I have the new tires but am concerned about swapping them. Reason being the boat is on the trailer. A Contessa 26, 5400 lb's. The trailer is a dual axle.










Two concerns;
1) Will the boat shift if I lift the trailer?
2) Where to I put the jack to lift the trailer? I don't want to load up the trailer in a weak spot.

Any thoughts? 
Am I over thinking this?
Ideally I would like to replace both rear tires and leave the front two until the boat is off the trailer(next spring) the rear two are in worse shape than the front two.

Thanks,
John


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## fryewe (Dec 4, 2004)

I changed all four on my tandem axle trailer with almost 10K pounds of boat on it. T


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## Sabreman (Sep 23, 2006)

Lifting the trailer a few inches to change a tire won't shift the CG enough to topple the boat. At a marina that I worked at, we had a trailer similar to yours that we used to move boats around the yard. We (I) routinely jacked up boats to position the trailer beneath it. An axle broke once and you'd be amazed how far a trailer can tilt without the boat falling. :laugher

A picture of the trailer from the rear would be helpful, but I'd position the jack beneath the axle as close to the tire as possible. As I lifted the boat, I'd place wood blocks (vs. cinder blocks) beneath each corner at the rear of the trailer to stabilize it.


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## leogallant (Jul 29, 2011)

Yes, it takes a lot to shift the boat. We jacked up 11,000 lbs of boat on trailer to block up and take pressure off tires while we work on it in our yard. 

When our friends brought it from their house to our yard, the trailer slipped and rolled back in their yard about 5 ft. until it finally bumped against wheel blocks. With 11,000 lbs rolling and then coming to an abrupt stop, they were freaking that the boat might slide right off the trailer! In fact, it only shifted 1 inch, amazing!


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## fryewe (Dec 4, 2004)

...sorry...hit the wrong key...continuing...the boat won't shift. Put the jack under the axle of the tire you are changing and use a short two by six on top of the jack to distribute the weight.


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## tommays (Sep 9, 2008)

Let's just the boat movers trailer LOST the whole wheel moving Seafever this spring and it lived


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## Barquito (Dec 5, 2007)

If you think about it, the trailer will be making some pretty big swings going over bumps on the road. OTOH, dealing with stuff that heavy, should have a little pucker-factor.


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## johnnyandjebus (Sep 15, 2009)

Thanks for all of the replies, I plan to tackle it this weekend as well as provide a pic from the rear.

John


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## hellosailor (Apr 11, 2006)

John-
Yes the boat will shift, but it does that every time the trailer tilts on the road anyhow. I wouldn't stand under it but I would expect it to stay put.
WRT jacking the trailer, was it professionally built? If so, see if the maker can tell you the jacking points they recommend. If not, look for strong points near the axle, perhaps between the tires, or under the axle/suspension.

What I would most strongly suggest is buying a pair of jack stands that are rated well above the combined weight of the loaded trailer. Once you have one wheel up, about an inch off the ground, insert a jack stand just outboard of that wheel. Now repeat with the other wheel, so there are a pair of jackstands taking all the weight.
Assuming you loosened the lug nuts just a little beforehand, you can now spin 'em off, one tire at a time, and replace them. The tires should probably be chocked--all four of them, both forward and rear--to make sure the trailer doesn't shift while jacking.
As to the jacking points...BMW finally stole my idea, get a 3" copper pipe cap, find the jacking points, epoxy or 5200 the cap to each jacking point so now the jack pretty much has to be centered in the right place. Or, at least gob on some blaze orange paint to make it real obvious for next time.
And of course, you'll want to store those jack stands somewhere on the trailer. If you don't have a box of some kind attached to it already.

This is also the perfect time to install a Grease Buddy on each bearing, or at least, re-lubricate and inspect them.

If jacking, chocking, all that stuff is news to you? Even if you don't have an auto club membership, it might pay to have someone in the tow business top by, at their convenience, to show you just how to do it. If you feel any uncertainty about it--there's nothing like seeing it done the right way first. $20 and a cold six, someone ought to be willing to stop by when things are slow.

And if you put just a dab of antiseize on each wheel stud before you put the lug nuts back on? Lasts over ten years, and you'll never have a frozen lug nut again. You should, btw, also be using a torque wrench to put on lug nuts.


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## overbored (Oct 8, 2010)

wow, lets see how complcated we can make changing a tire. Loosen the lug nuts on one wheel a 1/2 turn then just put the jack under the axle and raise the wheel off the ground. remove the wheel and install the new one. what do you think happens if you get a flat tire. the boat will not tip over. half of the weight of the boat is sitting low on the trailer. tandem axle trailers are designed to support the weight with only one tire on the ground.


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## rhr1956 (Dec 18, 2010)

Definately place the jack under the axle, not the trailer frame.


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## Capt-T (Aug 14, 2011)

In addition to keeping it simple, it is generally accepted for most applications that wheel lugs go on DRY.. otherwise you run the risk of over-torque. Anti-seize, although not a full blown lubricant is NOT recommended. Your torque wrench settings are assuming metal on metal contact with no lubricant.


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## hellosailor (Apr 11, 2006)

Those of you who think jack stands are overcomplicating life, have probably never seen a jack fail or a vehicle fall off a jack. If the ground is a little sandy, or not level, or the load not balanced, or the jack simply defective...a pair of jack stands is damn cheap insurance compared to having a boat fall on you.

And while torque specs are based on "dry/dry" there are compensations for using antiseize. If you've never had a stud snap off, often because some highly trained pro simply had his impact gun set on "max", or been unable to change a tire on the road because the stud was frozen, count yourself lucky. In 25 years of checking my car tires (when I mount the snows) I've found that only one shop actually torqued the wheels properly after removing them for a state inspection. Only one shop in 25 years, and at maybe 10 shops. Including a major service chain and a dealership. And I'm not talking about being off by 10%, they're usually been off by about 100%.

A little cheap insurance is a good thing, but if you'd rather rely on luck, go ahead. Luck is all it takes.


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## johnnyandjebus (Sep 15, 2009)

OP here, well that was anti-climatic as I hoped/expected. Two new tires in place, I'll be ordering two more on Monday. I won't bother with the details, with that said I agree a little insurance goes along way. The reason for posting the question in the first place. 

Thanks again for the responses.
John


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## SHNOOL (Jun 7, 2007)

yep simple... axle jack on the axle in question, loosen the lug nuts, jack away, change the tire, snug the lugs, lower, tighten the lugs, remove jack.. DONE... there is so MUCH lead in that keel, it's a NON-issue, COG is way lower than it looks.


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