Cross-threaded spindle nut
 

When replacing my rotors on my w123, I discovered that the mech that replaced my ball joints cross threaded the spindle nut. Now, it's barely threadable, but I was able to thread a new nut back on. Is there a way to clean up the threads, or should I be looking @ replacing the spindle.

You can try a die, but the threads may be weaked too much. Worth a shot based on cost and labor to replace the spindle.

Spindle would be safer since it is the only thing that holds the hub to the spindle.

Thread file
 

There is a tool called a thread file. They come in both standard and metric for all the different pitches. This is a great tool to have. With it you can file in a specific area that has a burr or defect. File a little and try the nut until it goes on right. However if the damage is too extensive you will be looking for a used spindle.

BTW - It took some talent to cross thread that nut.

So, just to clarify: a die creates new threads, while the file cleans up the current threads, right?

Also, does anyone know the pitch specs on the spindle, that way I get the proper sized file? If not, how do I measure. Thanks!

Yeah Matt, If you can get it cleaned up and reinstalled safely in case you must drive the car , But I would still be looking for a replacment spindle assy to install. Good luck Johnny

You can use the die to clean existing threads
 

The file is good for example if one area is damaged which would not allow you to even get the die started. You can work on a selective area with the file whereas the die goes all the way around the bolt, or spindle in your case.

With cross threading, a die may only make things worse because the die will follow the crossed threads, whereas with the file, you can file those threads away until the nut threads on correctly. Keep in mind that you are removing material from the threads, which is weakening the connection between the spindle and the nut. But unless the cross threading was severe, and it sounds like it wasn't because you got the nut back on then removal of material should not be an issue.

Thread pitch guage
 

Buy a metric thread gauge. The local hardware store should have one. The thread file can be had at a specialty automotive tool place - but I just looked and General Tool also sells them. Many hardware stores carry their line. Here is the General Tool link: http://www.generaltools.com/product.asp?action=prdupc&prid=119&sectionid=3
This is a close up shot of a Metric Thread File: http://www.generaltools.com/images/gtc_large/177-8.jpg
Hope it helps.

Did the mechanic admit to this damage?
 

otherwise, how did you find it out? or was it on the last brake job and you just noticed it on the newest job?
John

When I got the car (1 yr ago), the wheel bearings were shot. Did that myself, I had no problems then. About 6 months ago, I had the ball joint replaced. I let someone else do that. After getting tires a month or so ago, somehow, my rotors warped (gee, I wonder what could have caused that, had to use a 6' pipe on my breaker bar to get them loose :mad: ). When I went to thread the nut back on, it wouldn't start. After examining the spindle, some of the threads looked a bit beat.:mad: :mad:

A triangular jewelers file can be used instead of the thread file. It's just more time consuming and takes a bit more care. A thread file usually includes eight different pitches in one tool. (It's a double -ended square bar.)

That's not unusual. Wedging a large screwdriver in the slot to expand the nut sometimes helps. Remove the set screw first.

If you use the thread file rmemeber to star from the inside and work towards the eln of the spindle. Start from the good threads and work towards the bad ones.

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