new springs- axle over or under?

[KurtG]

OK, stupid trailer question.

I have been rebuilding my trailer and want to replace the slipper springs. Right now the axle is under the springs. I hadn't paid much attention, but most pics that I now see have it reversed with the axle on top.

I'm guessing I might get a couple inches out of flipping this for my shallow ramp (1" per 1') if I reverse the order when replacing them. Right now the boat sits quite high.

I cut the 30-40 rusted bolts (with advice for tools here), removed small amount of rust, cleaned and painted. I'm ordering a 8' long 2.5" square tongue to fit inside the current 3" square one to build an extension and am going to replace the bunks and keel rollers. I wanted to replace the springs as well (the wheels and axel look much newer) and was ordering the u-bolt kit.

Any issues on way or the other with the springs/axel? fwiw-I have 6 blocks to the ramp. So, no speed and not very far to go if that matters. I do have to get the rig inspected to get it registered.

 

[Silvertip]

Re: new springs- axle over or under?

It's not the springs that makes the difference, it's the axle. If you stand well in back of your trailer with it parked on level ground and look very carefully at the center of the axle, you may find that it is bowed upward slightly in the middle. This is called a cambered axle and the axle must be installed with the bend upward. Now then, you will notice that the spring perches where the springs sit on the axle, are either welded on top of or below the axle. If you were to flip the axle, the camber would now be in the wrong direction so you cannot flip a cambered axle. If the axle is perfectly straight (use a very long straight edge) to check this, then you can flip the axle and it makes not difference other than the boat will sit lower with the axle mounted above the springs.

 

[KurtG]

Re: new springs- axle over or under?

thanks so much.

The axle does have a bend. I thought it was down, but will check when I get home if it's not too dark. I thought the former owner mentioned replacing the axel and wheels (they look new). He only had a block to launch hand didn't use the trailer much (lives at marina). Could he have replaced it updside down?

The boat is not too heavy (15' w/40HP). Right now the trailer is empty.