[pcrussell50]

So I spent way too much time today trying to get the thru-axle on my Fox 40 to unscrew. Of course I totally stripped out the 5mm hex. That goes without saying. Even though I had completely removed all four pinch bolts, removed the little flat steel slit shim, and pried the jaws open a couple of millimeters with a flat blade screw driver. Anyhow, I finally got the m-effer (I rarely use foul language, but this was a cast iron bewitch) to unscrew by hammering a Torx bit into the ruined stripped 5mm hex hole and getting it loose with an impact driver, (NOT an impact gun, so you know).

Anyhow, there was evidence of a speck of grit, and a line of thread damage on the axle that probably coincides with the slit...

Anyway, I'm wanting to avoid this scenario again in the future. But I'm not sure how, other than to be surgically clean about re assembly.

Any other tips? And since I bought my bike used... is the Fox 40 supposed to have those slit shims? It's an air spring version, not the older coil spring version. Guessing around 2016-2018.

-Peter

 

[LarryFahn]

Put grease on the threads.

 

[pcrussell50]

Put grease on the threads.

I did.

It looks like a cut was made across the threads by the slit shim. Like this one:

Is this fork even supposed to use slit shims?

-Peter

 

[Shartist]

Late to the party, but I have a few theories. Lawrence Fahn is correct in that you should grease the threads regularly. Additionally, I have to wonder as to why is bound up so bad. My guess is that at some point your upper and or lower tube clamps may have been uneven, one of them was loose and the other wasn’t and the bike was ridden hard putting stress on the axle and damaging the threads. Check your headset, clamps, and stanchion height with some regularity making sure everything is aligned correctly and torque to spec.

 

[pcrussell50]

Late to the party, but I have a few theories. Lawrence Fahn is correct in that you should grease the threads regularly. Additionally, I have to wonder as to why is bound up so bad. My guess is that at some point your upper and or lower tube clamps may have been uneven, one of them was loose and the other wasn’t and the bike was ridden hard putting stress on the axle and damaging the threads. Check your headset, clamps, and stanchion height with some regularity making sure everything is aligned correctly and torque to spec.

Very insightful post. could be. and it was ridden hard at the bike park a few days before disassembly.

I put it all back together carefully (with grease), a slit shim in each pinch, and special attention to the tube clamps and any mismatching in clamped length.

-Peter