what size is the axle nut

On my '06 Sportsman 500, the rear axle nut is 30mm. I used a deep impact socket and a breaker bar. Soak it with penetrating oil overnight, then hit it with an impact gun if you have one. The nut is torqued to around 150 ft-lbs, so it's tough.

I've got a 2005 Sportsman and it's actually 1-1/8 inch (that's about 28.6mm). So check your year—Polaris changed somewhere around 2007 maybe. Better measure the nut itself to be safe. A 30mm might fit loose and round it off.

It's 30mm for most of those mid-2000s Sportsmans. I did mine last summer. Used a 30mm impact socket from Harbor Freight, worked fine. Just make sure you have a good impact wrench—my little electric one couldn't budge it.

I just did this job on a 2004 Sportsman 500 and it was definitely 30mm. But I've heard the early 2000s had 1-1/8. So yeah, measure it. Also, don't forget to loosen the nut before you lift the ATV or the axle will spin.

1-1/8 inch on my 2003. If you're buying a socket, get both 30mm and 1-1/8—they're cheap and you'll have them for other things. Also, use a six-point socket, not 12-point. A 12-point can slip and round the nut.

You might find that the nut is staked or has a cotter pin. Some models have a locking tab. Check that before you start. Also, if the nut is rusted, heat it up with a torch first. I had to do that on mine.

I disagree with the guy saying it's 1-1/8. I've owned three Sportsmans from that era and they were all 30mm. But Polaris did weird things sometimes. Best advice: measure the nut with a caliper to be certain.

If you're at AutoZone or somewhere, they rent out socket sets. Borrow a 30mm and 1-1/8 and see which fits before buying. Also, make sure you have a torque wrench to put it back on—you don't want the wheel falling off.

30mm for sure on my 2006. The nut takes some force to loosen. I used a 3/4-inch breaker bar with a pipe for extra leverage. Also, put the parking brake on and chock the wheels to keep it from rolling.

Check that the nut isn't a left-hand thread. Some axles are reverse threaded on one side. I doubt it for Sportsman but worth verifying. Also, wear safety glasses—if you snap a socket, bits fly.

I'd recommend buying a proper impact socket set. They're cheap on Amazon. The axle nut is usually torqued high, and a regular socket can crack. A set with both metric and SAE will cover you for other jobs too.

On my '05, it was 30mm but the nut was so rusted I had to grind it off and replace it. So if yours is corroded, consider buying a new nut ahead of time. They're cheap at the dealer or online.

Whatever size it is, put some anti-seize on the threads when you reinstall. Makes future removal easier. Also, torque it to spec—usually around 140-160 ft-lbs. Don't guess, or the nut can back off.

I used an angle grinder to cut a slot in a cheap socket to fit over the nut if it's rounded. But better to get the right size first. If you happen to have a 12-point socket, don't use it—6-point only.

Measure it with a ruler if you don't have calipers. 30mm is about 1.18 inches, so 1-1/8 (1.125) is slightly smaller. If it's a snug fit with the metric, it's 30mm. If loose, it's probably 1-1/8. But calipers are best.

Guys, stop guessing. The real answer is that Polaris used both sizes depending on production date. Some 2006 models had 30mm, some 1-1/8. So the only way is to measure the nut. I learned the hard way—bought a 30mm, had to return it.

I'd also check the axle itself. If someone replaced it with an aftermarket axle, the nut size could be different. My buddy put a SuperATV axle on his and the nut was 32mm. So verify everything before buying.

Safety tip: when you have the nut off, support the ATV securely on jack stands. Don't rely on the parking brake alone. And when you torque it back, do it with the wheels on the ground to avoid stressing bearings.

I own a 2008 Sportsman 500 and it's 30mm. I can't speak for 2006, but if you're near a dealership, they might let you try sockets in the parking lot. Or bring the nut with you if you can get it off.

Partial disagreement here: some people say use a torch on the nut. That can damage the axle seal or bearing. Better to use penetrating oil and let it sit overnight. Heat as a last resort, and only on the nut, not the axle.