I am building a small trailer for my Grandpa. He bought an old boat trailer frame that has 5 (3x3x0.125) rails that run the length of the trailer. I am suppose to narrow the outside to outside of the trailer to be 57" wide to fit his 244 IH tractor. He also bought two 5000lb axles to narrow for the trailer.

the tractor weights 2100lbs.

BIG question is can the axles be hard mounted to the frame or does that idea suck? I have an uncle with a 20+ year old stock car trailer with the axles hard mounted and he has never had any issues, which is why I was considering that instead of the extra $200 to put suspension on a light duty trailer.

The trailer is never going to be loaded up over 3000lbs.

If the trailer is only going to be holding 3000lbs and you have 5000lb axles just run a single axle if you MUST not use suspension.

If you don't have a suspension the trailer MUST be level when towing otherwise you will be puting more weight on one of the two axles.

Most farm equipment and lawn trailers (or anything you would pull behind a tractor) are hard mounted, so I don't see any reason why couldn't. Not like you are going 70 mph down the freeway.

If you put dual axles on it then I would suggest sometype of walking beam setup so the axles can pivot otherwise you will constantly have one or the other off the ground unless it's perfectly flat.

Not that it matters if the most weight either axle would see is under 5,000lbs.

Many states require suspension.

no suspension is going to put the duties of a suspension on the tires. trailer tires blow out far more often than normal tires for this reason...

trailer is getting suspension, he is whipping out the dough for that.