48 replies to this topic

[Nu2mini]

Yes it does pose issues.....

1) Due to the amount of wear over the years, it will be almost impossible to re lap in a ball joint.
2) They wear into an oval pattern.
3) This oval pattern if disturbed will create a situation where the joint is either very loose at some points and very tight at other points, now the loose points will cause the issues that you are "attempting to adjust to remove" and the tight "spots" will cause a very dangerous situation where the joint can be moved into an area of fatigue stress failure

In other words is your life worth the £20 for a pair of ball joints that if fitted correctly will last for years

Ask how many Mini owners have had sudden failures with ball joints... and within reason I would almost gaurantee that they where adjusted within the last 3 months prior to failure, depending on useage of the car of course.

Thanks MRA for the advice. I will certainly be replacing instead of re-shimming

[jaydee]

Just wondering what is the collective wisdom with regards to re-shimming the joints. Does it pose any dangers, presuming you can re-establish a good joint. I'm also assuming it removes any need to lap as the joint will have made its own mate. I do realise this is subject to a close visual inspection of both the ball and cup

Personally i'd never reshim a balljoint, if its worn, its worn- it needs replacing.

In other words is your life worth the £20 for a pair of ball joints that if fitted correctly will last for years

Wise words!

[peter-b]

Total waste of time if you ask me, fit them right at first then check and adjust in about 5,000klm. From then on they'll last well with regular lubing.

[Nu2mini]

............... fit them right at first then check and adjust in about 5,000klm. .............

What sort of adjustment can you make that doesn't involve re-shimming ???

[lrostoke]

I suppose one way of looking at this is that a lot of cars use non adjustable balljoints that just bolt on and off. Also in essence the trackrod end is a ball joint. Both these types just get replaced when worn.
So why would you treat the mini balljoint any different, shim correctly when fitting, once worn replace with new.

[MRA]

Total waste of time if you ask me, fit them right at first then check and adjust in about 5,000klm. From then on they'll last well with regular lubing.

Sorry, but if you fit them correctly in the first place then adjustment later is not required, if you just fit them out of the box.... they wont last as long, but more importantly adjusting them is a potential safety issue, it may be fine with yourself.

However if you then sell your Mini (or work on someone elses) and the next person is a little more ambitous with their driving style then they could quite easily be using the area of the ball joint that is in a fatigue stress region and failure can then happen quite quickly, because the "new driver" drives a little faster the blame is automatically placed on their shoulders when in fact it is the previous mechanic or grease monkey that should be pulled up and made accountable for their shoddy workmanship. Unfortunately this is yet to happen, it will happen with new EU laws, (obviously doesn't apply to Australia) however these things have a habit of migrating...

Why risk spending 6 months in hospital or worse.... when doing the job properely takes a few hours ?? Some peoples logic really baffles me when it comes to safety

[Gr4h4m]

If that is the video were they use a drill to lap in the parts then no that is not correct........ as it will cause local overheating and smear the metal causing more harm than good

Just as a side note, whilst i understand this could happen I just don't believe it at the speeds the drill was going.

[MRA]

I understand what you are saying but what is happening is on a micro level, so the heat can dissipate quickly but not quick enough to avoid damage, speak to a metalurgist about heat stress in surfaces in contact without lubrication etc....

[Kinky_Kylie]

If that is the video were they use a drill to lap in the parts then no that is not correct........ as it will cause local overheating and smear the metal causing more harm than good

Just as a side note, whilst i understand this could happen I just don't believe it at the speeds the drill was going.

Although the drill may not be putting out many rpm the surface speed at the very top of the ball joint will be unreal!!!! its this what will cause localised over heating allover the ball joint as you move it around.

[Gr4h4m]

Whats the result of the over heating in real terms on the road?

[MRA]

If the heat treatment is compromised the metal will be softer and allow the surface to "pick up" this could and often will then sieze, if your ball joint siezes it will then be in a serious risk of fatigue

[mk=john]

Hi rob (The plod?!!!)

Like valve grinding, it ensure the parts are perfectly seated. When you buy a ball joint and try to shim it with the supplied shims, you will more than likely notice the ball sticking tighter in certain orientations, and be looser in others. If you lap the ball into the socket with valve grinding paste, it will seat the joint properly. Thats what i did with mine on mu Mk1 rebuild.

Remember to remove every trace of the grinding paste after you are finished, for obvious reasons, and assemble the joint as normal

[Gr4h4m]

If the heat treatment is compromised the metal will be softer and allow the surface to "pick up" this could and often will then sieze, if your ball joint siezes it will then be in a serious risk of fatigue

Well, so far those ball joint in the video have benn on my car for over four years and so far so good but I do keep an eye on them, like most things on the car. The car does 3-5K a year. inc some track time.

[MRA]

Unfortunately it is subjective, much the same as "hand tight".... hand tight for me is different for someone else's "hand tight".

It may work for 90% of the population who use a drill to lap in their ball joints, but if it fails once and leads to a road death, who is responsible ?

In the automotive world vehicle testing is subjected to the 90 percentile, and higher depending on the system being tested. what this means is just because you are only doing 12,000 to 20,000 miles doesnt mean that your mileage is within the 90% of users, it may be more than or less than the 90% but if the S*** hit the fan you would have to prove that your figures were gained from the correct source/s

For safety crircal parts the 90% becomes 99 or higher, ie 1 failure in 100,000 for example.....

If it's your video then maybe altering that section to either show more accurately how you used the drill and pointing out the reasons why it is done that way or simply change to hand lapping for safety reasons.

[Cooperman]

If the ball joints were 'lapped-in' as a part of the production process on a volume production line there is no doubt that an automated process would be used - it would certainly not be done by hand. The issue, as I see it, is not the use or otherwise of power tools, it's the method used. If you put the cap in a vice and the ball-shaft in a high-speed power drill, add a bit of lapping paste and 'wiggle it about whilst pulling the ball hard into the cap' then, as Martins so rightly says, you may well cause damage to the ball pin assembly.
However, if you put the ball-shaft in a very low-speed pillar drill with the cup held lightly in your fingers and lots of fine paste and lightly move the cup in an oscillating motion without using any significant pressure it'll be fine.
Just make sure you clean all the paste out before fitting.