Topic: Stripped Front Axle Bolt

[BrickWoll]

I think I may have just ended my riding season.  While going through my front end bolts, confirming they were torqued properly, one of the two front axle nuts released while tightening. 

The bummer is I almost never use a torque wrench on this bike for this very issue.  Not enough feel.

I'm wondering if anyone has ever tapped the fork threads?  I can't think of another option other than replacing that fork. 

Any thoughts appreciated. 

'77 CB550 K3

[calj737]

Forks are aluminum and easily tapped if you have the correct tap (that will be pricey for a single tap). I’m struggling to recall at the moment, but I can’t recall the actual fork being threaded; I thought it was captured?

Edit: the fork is definitely not threaded. The axle is. The capture nut is steel and can be tapped or replaced.
https://www.cmsnl.com/honda-cb550-four-cb550k3-1977-usa_model1015/partslist/F++09.html

[bryanj]

Do you mean the big nut on the axle or the 2 nuts each side holding the clamps on?

[BrickWoll]

Forks are aluminum and easily tapped if you have the correct tap (that will be pricey for a single tap). I’m struggling to recall at the moment, but I can’t recall the actual fork being threaded; I thought it was captured?

Edit: the fork is definitely not threaded. The axle is. The capture nut is steel and can be tapped or replaced.
https://www.cmsnl.com/honda-cb550-four-cb550k3-1977-usa_model1015/partslist/F++09.html

I appreciate the response, calj737.  I wasn't being clear.  It's one of the TWO bolts that hold the clamps onto the forks from below. 

Do you mean the big nut on the axle or the 2 nuts each side holding the clamps on?

bryanj: Two smaller bolts that drive up into the fork from below to keep the clamp on.

[calj737]

Those should be studs, not bolts. 8mmx50mm studs with the half clamp passing over them, then a nut and washer to secure them from below.

So what part is actually stripped?

[newday777]

Forks are aluminum and easily tapped if you have the correct tap (that will be pricey for a single tap). I’m struggling to recall at the moment, but I can’t recall the actual fork being threaded; I thought it was captured?

Edit: the fork is definitely not threaded. The axle is. The capture nut is steel and can be tapped or replaced.
https://www.cmsnl.com/honda-cb550-four-cb550k3-1977-usa_model1015/partslist/F++09.html

I appreciate the response, calj737.  I wasn't being clear.  It's one of the TWO bolts that hold the clamps onto the forks from below. 

Do you mean the big nut on the axle or the 2 nuts each side holding the clamps on?

bryanj: Two smaller bolts that drive up into the fork from below to keep the clamp on.

The axle clamps are held on with studs not bolts. #24
Is there any of the busted stud sticking out to get hold of with vice grips to unscrew it from the fork leg? If so then you just replace the stud and nuts. You aren't the first to break a stud.

https://www.southsoundhonda.com/--xpartsstream#/Honda_Powersports/CB550KA_(77)_550_FOUR_K%2c_JPN%2c_VIN%23_CB550K-2000007_TO_CB550K-2015308/FRONT_FORK/e78b9119-f792-4cf6-ab47-c471041bb569/9fd2cbd7-9789-4219-8314-c29c084cee8c/y

[newday777]

What was the torque setting you set it to when it broke?
Did you back off the nuts before you put the torque wrench to it? That is the correct way to use a torque wrench, not just test the pretightened nut for proper torque. 😉

[70CB750]

Forks are aluminum and easily tapped if you have the correct tap (that will be pricey for a single tap). I’m struggling to recall at the moment, but I can’t recall the actual fork being threaded; I thought it was captured?

Edit: the fork is definitely not threaded. The axle is. The capture nut is steel and can be tapped or replaced.
https://www.cmsnl.com/honda-cb550-four-cb550k3-1977-usa_model1015/partslist/F++09.html

I appreciate the response, calj737.  I wasn't being clear.  It's one of the TWO bolts that hold the clamps onto the forks from below. 

In theory, it should be possible to replace the stud. In reaĺ life it could be very difficult getting it out. 

Heat up the aluminum end and if the method of two nuts does not work, weld a nut on the stud.

[bryanj]

As said should be studs and they can be helicoiled if the thread has gone in the ally slider but i would want the fork on the bench and not work upside down

[BrickWoll]

Thanks for the responses.  Clearly from the parts drawing they are studs, but mine are bolts.  Could this be PO antics?  I'm traveling but will post pics when I'm back in the garage.

[bryanj]

Definately po messup, change to studs, there may be enough thread deeper in the alloy to hold a stud. You can use M8 threaded bar if you cant get proper studs

[calj737]

You can use M8 threaded bar if you cant get proper studs

Why on earth switch from a bolt to “threaded bar”? Use studs, or use proper bolts. The reason to use studs is the unthreaded gap forces the nut to apply pressure against the threads in the fork upper. A bolt or “threaded rod” don’t do this. It’s not about the nut, it’s about the split threads.

What dumb advice….

[bryanj]

Because the op may not have acess to proper studs plus the holes are deeper threaded than original studs so longer ones MAY hold without helicoil as it sounds like the op is away from home, you would still use nuts, washers and spring washers so not wear any more the threads in the slider.

[smee]

I've had to do this fix before. Used some heat on the end of the fork and vice grips to carefully back the remaining stud chunk out. Brought the piece to Ace hardware to get a matching 8X50 stud (also available on Partzilla as an example). Worked great. Make sure to install the end holder piece in the correct orientation.

[bryanj]

From the original post its not broken its he the thred stripped out