Can You Tell Me What This Mystery Axle Is?
We get this question a lot, someone will send us a grainy photo of a mystery axle, still under the vehicle or piece of equipment, 1/2 buried in the ground, covered in grease, wondering if we can provide information like; gear ratio and bolt pattern on it. Unfortunately, things aren't that easy. First off, there are thousands of different axles out there, just because its a Rockwell doesn't mean it has anything in common with the Rockwell’s we deal with regularly.
Axles can also be made specifically for a manufacture, say for example; a Rockwell axle is under an old forklift and made by Rockwell specifically for that piece of equipment. Often meaning, you have to go through the forklift manufacturer for parts (if they still exist).
The best way to identify an axle, is by the ID tag or numbers stamped on it. Unfortunately, the older the axle is, the less likely the tag will still be there. Often it is held on by 2 rivets on the axle tube near the center section. Clean the grease and dirt off and start there with a simple google search. Another not so common way to identify an axle is stamped numbers, sometimes there will be a flat spot machined on the axle with numbers stamped on them. Rust, dirt and paint can make these difficult to see. Casting numbers are almost useless, (raised numbers you find in different location on the axle that are cast into the part when manufacturing) don't do much to identify the axle.
So, what do you do if you can't identify an axle? Best bet is to walk away, just because its super cheap and looks like a big strong axle for your next project doesn't mean you should buy it. Replacement parts will be almost impossible to find, although you might get a few seasons out of it before something fails eventually you will need a new seal or bearing.
How Do I Run a Steering Axle in The Back of My Rig?
This is also another common question, despite popular belief taking a steer axle and putting it in the back of a vehicle will not cause it to spin backwards trust me on this one!
The only time you will have issues with an axle spinning the wrong direction is if you have a rear mounted engine, by flipping the engine to the rear you will be changing the direction of rotation in the entire drive-train. There are 2 ways to fix this; Option 1: You can run a reverse rotation gear box, this will change the direction of the input from the output rotation; Option 2: Flip the axle or carrier upside down, by running the pinion off the opposite side of the ring gear this will reverse the rotation of the axle, see diagram at the bottom of the page.
This is often thought of as the easiest or cheaper solution, however this brings up a whole slough of other issues. To start flipping a steer axle upside down, will ruin the caster and camber that was set from the factory in the knuckles. This can be fixed by cutting off and re welding the tubes. Another issue is, if the axle is set up to run on the drive side of the ring gear teeth flipping the carrier will often cause the pinion to ride on the opposite side of the ring gear, the coast side. This is typically the weak side of the gear to run on and can cause premature failure. Another issue is proper oiling, axle manufacturers design oil ports and galleries inside a differential to help keep carrier and pinion bearings properly lubricated, by flipping things 180 it throws all this out the window, depending on the axle it could cause premature or almost immediate failure.