What size are the rear axle adjuster bolts
 

Today I was trying to find out what size adjuster bolts are on the my 2018 Softail. I will have to go out and buy a socket for those bolts so I need to know the correct size and type for the axle adjuster bolts. Thanks

A 10 mm spline socket will work. You can but a whole metric set for about 15 bucks from Harbor Freight

What is the difference between a spline socket and a 12 point socket? Or are they the same?

12 point has more of a star shape. Spline socket is just a round socket with straight ridges...a 12 point might work, I didn’t have one to try. I bought the spline sockets a year ago for a job on my car and figured I’d try it on the axle adjuster, and it worked

1/2" - 12 point.

https://cimg2.ibsrv.net/gimg/www.hdf...a1b57c06e1.jpg
https://cimg2.ibsrv.net/gimg/www.hdf...c0da586b2e.jpg

Thanks

After a 2nd look at the parts diagram, I don't think it's 1/2", but it's definitely 12 point SAE. Grab your box ends (most are 12 point), and test fit to determine the correct size.
https://cimg9.ibsrv.net/gimg/www.hdf...6af146a841.jpg

Just checked and it's definitely a 3/8 thanks for your help

Good to know. Even though a 10 mm would likely work (with a little slop), it's always best to use the correct tool.