This is yet another of our tech advisorys

It seems my half shaft snapped off at the outer end and this was caused becuase both of the rear wheel half shaft outer nuts loosened up after so many drag runs

It seems the loose nuts caused some play in the splines which led to the half shaft failure

I would suggest that any Evo owners who are going to the track or driving the car hard take out the cotter pins and check the trq on those axel nuts

Cheap insurance which could avoid breaking parts as what happend to me !

 

Good advice......can you tell us what is the correct tq spec. for the axel nuts?

thanks

 

225 +/- 25 N-m
or
166 +/- 18 ft-lb

 

How can the nut come loose if the cotter pin is still in?

 

If the metal in the splines streches out slightly under heavy launching

 

That won't cause the nut to come loose per se, only the axle to get 'longer'. I wouldn't drive on a stretched axle. How many times can you tignten the nut before the axle snaps? How many passes do you have on the car?

 

It had at least 100 passes - - Its just something else I am going to keep an eye on and I am posting here to keep others from having same issues

 

I'm not trying to start an e-spat Al, just trying to understand what is really happening. I will be checking the wheel nuts next time I throw the race tires on, but if it's loose I'll be looking to get a new axle ASAP. Thanks!

 

I have seen on some racing teams that they draw or paint a straight line down the
length of the halfshafts and then periodically check what it looks like.

The shaft gets replaced when the line twists half a turn around.

Now that's torque ...

 

I am thinking that it would prob be a good idea to toss the axels if they are loose also - but you may be better off to re tighten it than to just leave it loose

Either way its just a matter of a learning curve and I like to post the info here so others can be aware of what is going on