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Brian Vogel
Grand Master
Username: guyslp

Post Number: 1793
Registered: 6-2009
Posted on Tuesday, 15 December, 2015 - 11:27 am:   Edit PostDelete PostView Post/Check IP

Suspension/steering is an arena in which I have zero experience, and I recently had someone asking me a question about this ball joint:

Upper Ball Joint with Pitting

I can see the pitting on the top, but this appears to be a casting artifact rather than the result of corrosion. I also thought these things are coated in grease inside the cup in which they rest, so if there are pits, as opposed to raised sharp bits above the ball, it really shouldn't matter.

All of the above being said, that's pure conjecture and I would really like to know whether that would be true or not. I have not offered an opinion because I'm not qualified to offer one.

At some point in my future dealing with one of these things will likely be in the cards, whether I want to or not, and I'd like to know whether these things are like the head on, say, a human joint implant (meaning, perfectly smooth and polished to a fare-thee-well), or are polished such that a spherical surface is present, but there may be tiny surface imperfections such as shown in the photograph.

Brian
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Jim Walters
Frequent User
Username: jim_walters

Post Number: 58
Registered: 1-2014
Posted on Tuesday, 15 December, 2015 - 12:19 pm:   Edit PostDelete PostView Post/Check IP

It's absolutely shot. Those are deep corrosion pits that will chew up the socket. It has worn through the hard surface layer and is extremely corroded. Unless it's smooth and shiny with no ridges or pits it is shot. Here is a photo of a used one that has been greased regularly and is what a new or even good usable used one should look like.




SRE22493 NAC-05370
www.bristolmotors.com
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Brian Vogel
Grand Master
Username: guyslp

Post Number: 1795
Registered: 6-2009
Posted on Tuesday, 15 December, 2015 - 12:27 pm:   Edit PostDelete PostView Post/Check IP

Jim,

Thanks very much. This is precisely what I wanted to know.

The cure for ignorance is so simple: ask a group of people who know!!

Brian
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1408
Registered: 6-2006
Posted on Tuesday, 15 December, 2015 - 12:45 pm:   Edit PostDelete PostView Post/Check IP

Not much to add to that reply nd the pictures just about say it all anyway.

I think it was on this forum that I recently posted on a thread about greasing your balls.

I mentioned that you never really get play in RR ball joints. This is because rust fills the wear gap.

There is a short period when the ball and cup are worn but the rust has not taken hold yet.

I would say that the top photo has probably captured that point. The ball is chafed and fretted so the hardened layer has worn through, but the rust hasn't formed yet.
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David Gore
Moderator
Username: david_gore

Post Number: 1851
Registered: 4-2003
Posted on Tuesday, 15 December, 2015 - 12:58 pm:   Edit PostDelete PostView Post/Check IP

Well done cohort - it is certainly corrosion pitting most likely exacerbated by split rubber boots that were not replaced early enough and which did not receive regular greasing.

Note the elliptical shape of the area of greatest pitting - I would expect this to have been immediately beneath the split. The offset of the ellipse would be directly related to the angle of inclination of the ball shaft relative to the socket housing.
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Geoff Wootton
Grand Master
Username: dounraey

Post Number: 1040
Registered: 5-2012
Posted on Tuesday, 15 December, 2015 - 01:00 pm:   Edit PostDelete PostView Post/Check IP

It's such a blessing to have two RR experts on this site. A big thank you to both of you for all the advice you give.

Geoff