Hi all
I have a rough running front bearing so I have purchased from Mx5 parts a hub and integral bearing. I would appreciate it if anybody could answer a few questions before I start.
Is the axle nut self locking and/or some type of crush washer that needs to be replaced every time? I have ordered one just in case.
does the ABS sensor need removing first?
Is there a proceedure such as torquing up and then backing off?
What is the final torque setting?
Is there anything else I should know?
Thanks
It’s a stake nut and should be replaced once removed.
There is no need to disturb the ABS sensor.
Just torque to 200Nm and state the nut.
If you can get your hands on a copy of the October 2010 Owners Club Magazine, Soft Top Hardtop there is a how-to guide in there. If you join the club you can download a PDF of the guide.
Thanks for very prompt repy. Forgive my ignorance but I’m not familiar with the term “stake nut”.
It’s a nut that’s secured with a metal tab.
Use a blunt chissel to bend the end of the nut…
…into the groove in the stub axle. It prevents the nut working loose once torqued up.
A picture says a thousand words
Hi all
Thanks for the photos. I’m sorry not to have replied earlier but I’ve had to do other things.
Anyway the parts finally arrived and the job has now been done and the new bearing is a complete success.
Just a few notes which might be of help to somebody.
The first thing to do was to “destake” the nut. The metal was quite soft and the indent knocked out easily with a punch. I think the nut could be reused but no doubt the purists would disagree. The replacement nut is much harder. The nut is 29mm AF and socket sets do not have 29mm sockets nor do Halfords. However a local tool shop had a 1 1/8" AF socket which fits like a glove. Loosening the nut is the next problem, I now have a slighly banana shaped tee bar in a failed attempt. In the end the use of the ratchet handle which is rigid and an extention tube shifted it. Brute force and ignorance has it’s uses! After that fitting the new hub was straight forward.
From other forums it would seem that short life of bearings is not unusual. I have a couple of thoughts as to why this might be.
Keeping water out of the bearing has to be important. The inner part of the bearing has a rubber seal which rotates against the fixed axle casting. In my case there was a 1/2mm gap and the surface of the casting was rusty, it seems likely that water has got in and corroded the bearing. The new bearing is a much closer fit but this design is always going to a problem and while it might keep out water when the wheel is rotating, if for instance you go through flood water there is a good chance water will get in.
The other point is the high torque and consequent high axial thrust on the bearing. This is no doubt considered neccessary for a sports car where high cornering forces are to be expected but the result is a short life. I finally torqued it up to 190Nm, that felt quite enough.
And so to the next job , but that’s a story for another day.