55 replies to this topic

[PaulColeman]

I've just finished shimming the new balljoints I've fitted. What I'm not sure about is when it says they need to be able to move with some friction exactly how much are they talking about? There seems to be differing amounts of friction depending upon the position of the balljoint itself. When the balljoint is vertical there is more friction than when it's laid over at an angle. Is this normal?

Thanks, Paul.

[sonikk4]

I have got the same issue with mine well at least least two of them. The other two are either loose or bind so they will need some more lapping which is tomorrows job.

[PaulColeman]

I got the shims down to the point where I have about 0.0018" but then an extra 0.0002" is too sloppy, 0.0001" is as described above and 0.0000" is so tight it won't move. So I don't see what more I can do with it as the thinnest shim I have is 0.0001".

I think I'm going to go with what I've got as they will wear to some degree I'm guessing.

Cheers, Paul.

[jaydee]

They dont have to feel notchy, try lapping them gently with valve grinding paste
You have to move them with your fingers and the movement has to be smooth

[Spitz]

Sounds like more lapping is needed......moving the joint to different angles while doing so.

[MRA]

Marvelous excellent answers, removes notchiness and extends the life of your balljoints as well...

Please don't do this to used ball joints though as it simply doesnt work and will often result in a potentially lethal accident when one or the other breaks.

[dklawson]

For VERY minor adjustments where you want that last, extra 0.001" or so, try a minor change to the nut. Take the nut back off and place a piece of coarse wet/dry paper on top of a piece of glass then lap the bottom edge of the nut just a tiny bit. I stress "tiny". You are not trying to make major changes. Also, do not do anything to the nut until you have tried lapping the parts as Jaydee suggested. The lapping can significantly change the number of shims required. Obviously clean the parts thoroughly after lapping.

I do one thing differently than described in the manuals. I clean the hub thoroughly around the threads, then put the shims on, followed by the lock-tab. It's a minor change but putting the shims on first allows the lock-tab to protect the shims from damage when you torque the nut.

[MRA]

I do something different as well Doug, I don't fit the lock tab, as they are softer that poorer quality steel than they used to be and I have found that they "move" with use, ie deform which then means thay are loose :-(

I use an extra strong thread locking compound and have done this for over 20 years.

[MRA]

I got the shims down to the point where I have about 0.0018" but then an extra 0.0002" is too sloppy, 0.0001" is as described above and 0.0000" is so tight it won't move. So I don't see what more I can do with it as the thinnest shim I have is 0.0001".

I think I'm going to go with what I've got as they will wear to some degree I'm guessing.

Cheers, Paul.

Paul,

Not meant as criticism but you have 1 too many zero's in your numbers above

Also if they are too tight you find that they just don't move when they should and this will cause fatigue, you will then have a catastrophic failure with obvious repercussions.

[crock]

How does the car drive differently when you have lapped the ball joint correctly? In other words, what do you notice when driving the car that tells you the ball joint needs work?

[PaulColeman]

Paul,

Not meant as criticism but you have 1 too many zero's in your numbers above

Also if they are too tight you find that they just don't move when they should and this will cause fatigue, you will then have a catastrophic failure with obvious repercussions.

Yes you are absolutely correct 0.0001" should be 0.001" D'oh!

Cheers, Paul.

[Tamworthbay]

Some good advice above, whatever you do DON'T follow the advice in the MIni magazine recently, they said to do them tight enough that they could be moved by a ring spanner over the stud but not by hand. This is way too tight and will most likely cause failure. If you use valve grinding paste or similar to lap in the new joints (well worth doing), make sure you clean all of it off before assembly. Brake cleaner is really useful as a general cleaner for this sort of thing.

[rally515]

I know alot of people will be checking back on this thread for more info they may not know
so i have a question:
What valve grinding paste should i use course, fine or both ?

Cliff

[skoughi]

Marvelous excellent answers, removes notchiness and extends the life of your balljoints as well...

Please don't do this to used ball joints though as it simply doesnt work and will often result in a potentially lethal accident when one or the other breaks.

Hi, I've just done this to my used ball joints,by that I mean lapping them in. Why shouldn't I have done this to used ones? I didn't do a lot of lapping, only enough to obtain a smoother action as I wasn't wanting to remove a lot of the surface of the cup. As a set of new balljoints dosen't cost the earth then I can replace them but Im on a budget so if I can refurbish something I will! I also noted you not using the locking tab, I will have to buy new ones as mine look like they've been run over or do what you do and bin them for locking fluid, but then I suppose having a locking tab will protect the shims.

[MRA]

Fine grinding paste, if you have to use course then they are too poor in quality.

The reason is that used ball joints will wear oval, the amount of wear is usually toomuch to simply lap out, with lapping we are talking a 3 ten thousandths of an inch (0.0003")

I have done a fair bit of work on these over the years and found that the wear will be a lot greater than the amount that can be lapped off.

What happens is the ball is oval and the cap is also oval, when you "tighten" the cap down you will either have a loose fit or a fit that is tight in certain areas, ie on full lock when on a bend, the ball joint binds up before this and is now being bent backwards and forwards, thus causing fatigue.

using a spanner is ok, as it means that the forces to move the ball joint are relatively low, the problem arises when you have a long lever or superman hanging off the end, I would suggest that you get a balljoint from another car and compare the difference, but if you can move it by hand it is too loose. Unless you in fact superman......