Jump to content

Stress, metal fatigue and snapped stub axle.


Guest Anonymous
 Share

Recommended Posts

Guest Anonymous

I raced last weekend at Le Circuit Mt Tremblant when a stub axle snapped, right in a medium speed corner (60MPH). By chance, as soon as I heard the noise, and the sudden high rev of the engine, I managed to brake, just beofre the drum separated from the trailing arm. It cut enough speed to safely go into the grass. And thanks to a very stiff suspension, I rolled on three wheels. No harm.

First question I asked myself was: cvould I have prevented this from happening? Especially with a 34 year old part. The answer is yes.

In the past few events, I have tightened the castelated nut several times. The hub was always a bit loose. It was loose because the spline were being beat up by the high stress of track. I thought it was the bearings that were going bad. Nop. Bad splines and stretching metal. The inevitabler happened.

So, for you guys, If you ever encounter those symptoms, do not delay and change the stub axle. It takes 30 minutes to do and can save your life.

In my case, I am going for axles from the 320, along with its 320 hub. The splines are finer, triangled and the parts are 10 years newer...

Link to comment
Share on other sites

Guest Anonymous

Thanks for the post Lee, everyone should defintely be aware.

They don't fit into the 02 trailing arm with zero mods, do they? I have a set of 02 arms and e21 arms (and 323i arms) and I remember looking at them and thinking it would not be possible to swap the e21 stubs. I think the issue was the axle would then be way too long, would it not?

If you can do it, it would be a nice upgrade!

Matt

'72 02/m20

Link to comment
Share on other sites

Guest Anonymous

The 2002 and 320 hubs have same depth/thickness. The 2002 and 320 share the same rear wheel bearings. I do not know about the 323 but I am certain that the 320 and 2002 stub axles can be interchanged. I will verify next week when I get a set of 320 stub axles.

Link to comment
Share on other sites

Guest Anonymous

I was pretty sure that the stub axles 'stick out' a lot more in the inboard side. Which would mean that the axles would have to be way shorter...like 4 or 5 inches I thought. I didn't look THAT close though. Hopefully you can make it work, that would be slick man.

Matt

Link to comment
Share on other sites

Guest Anonymous

I seem to remember checking this out, and I think the stub axle itself is larger in diameter on an e21, and the outboard hub has a different diameter as well. Because the splines are different from the 2002, you need to use the matched e21 stub axle and hub, and the larger diameters won't work with the 2002 trailing arm.

Depth is about the same, though.

Then again, my memory could be hazy.

Mike

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Upcoming Events

×
×
  • Create New...