10 replies to this topic

[Nu2mini]

Hi

Just lapping a ball joint for the first time and wondered how long I need to keep going. Hopefully the photos will show where I'm up to. The cup has developed a small polished section from top to bottom, about 2mm wide The rest is still matt. The ball has a polished strip 2-3mm wide all round the circumferance. I've been lapping by hand. Should I keep going in order to polish the cup all the way round ???

Attached Files

•  P1000871.JPG   5.13MB   15 downloads
•  P1000877.JPG   4.46MB   9 downloads

[abe46]

This video might be helpful..

[grahama]

A few seem to use this method, might be a little quicker but be careful of over doing it

[charie t]

Are you actually using any grinding paste?
30 secs normally does it

Edited by charie t, 26 February 2012 - 08:32 PM.

[Nu2mini]

Are you actually using any grinding paste?
30 secs normally does it

I've stopped because I've had enough using rubbing compound for paint work. I will get some grining paste tomorrow. Will this be more aggressive ???

[Neildanks]

yes very much so

[The Matt]

Yes. Use FINE lapping paste.

[Nu2mini]

yes very much so

Right then down to the motor factors on the morrow

[charie t]

I've stopped because I've had enough using rubbing compound for paint work.

If you gave up because of that, you'll be even more fed up trying to lap it in without paste

[Nu2mini]

Interested in how tight the joint should be when I shim it. The video seems to show it fairly loose. The grease seems to tighten the joint quiet a bit.

[tiger99]

The joint MUST be loose. i.e. you should be able to deflect it through its full travel with fingers only. If not, there is a very real danger of fatigue fracture at the neck of the ball pin, which is likely to cause a serious accident.

Some people insist on them being tighter, but those I have done all lasted at least 60k miles, and did not knock or rattle. A thou of free play does no harm, any more and if the shims can't set it accurately enough, you can lap a little bit off the flat face of the ball nut to tighten it up slightly. You would do that lapping on a sheet of abrasive paper taped to a very flat surface such as a piece of plate glass, or on a carpenter's oilstone.