Harbor Freight spring under axle conversion

Replace the U-bolts and spray the axle with POR15 or truck bed liner to keep it from corroding in the inverted position.

These little trailers will last a long time and take some abuse if you keep up on annual lube replacement. Mine lived outside for 14 years and was still going strong right up to the point when someone ran into it...

Those tiny trailers do not use cambered axles. My 1990 utility trailer had the axles mounted on top of the springs originally. It was made out of sheet metal bent into a channel with the stub axles welded onto it. The material was much thinner than the one pictured. I have since made new tubular axles (tandem) and mounted them under the springs. In the end as long as you don't exceed the 1000 pound capacity of the trailer that axle would be fine.

Heads up, the toe angle of the wheels is set (formeed) into the axle by the direction of traveling forward with the axle up (Top)and the wheel camber too. If you have "toe in" now and flip the axle upside down it can become "toe out". And postive camber becomnes negative camber, A no no. This may affect tire wear and trailer tracking.

Normally the over/under conversions do not rotate the axle, they move the spring pack and they change the axle seat. This way wheel toe and camber are not affected. Trailer slang called "axle flip" is techncially wrong. It is over/under. There is no flipping of the axle itself.

Like this,
http://www.dexteraxle.com/inc/sdetail/1093/1099

Instructions
http://l.b5z.net/i/u/6149609/f/Instruction_Sheets/059-551-00A.pdf

Hope this helps

John

i had thought about welding a little piece of steel thicker than the height of the centering bolt and then drilling a hole as you described, yet i didnt know how difficult it would be to get it all centered and aligned again/drill ht holes in the correct spot.

and yes either way I think I am going to go to a local trailer supply store and get new u-bolts and hardware.

The axle will not be as strong while it is inverted, because in that configuration you lose compression strength on the top of the channel and that will allow more flex under load. Also, being open side up its a rust trap. One easy work around would be to weld a plate on to the open side of the channel, while will allow you to keep it right-side-down, and also allow for spring locating if you drill a hole in the middle.

I would be suspect on the hardware used. Chinese steel can vary dramatically because there is little supplier control. While those U-bolts would certainly be adequately sized if they were from a North American supplier, I wouldn't count on them holding up if they are chinese. Since the axle is now under-sprung, the U-bolts are now supporting the load, instead of just locating the axle. It looks like a light-weight trailer, so maybe it doesn't matter. But if it were my trailer, I'd be sure I bought the u-bolts from a trusted source.

If you are sure the axle is straight the my only thought is what is going to set inside the channel, Water or dirt.

Most people just weld a new spring perch on the opposite side of the axle. But then again most people want to raise their trailers not lower them