pitman arm ball joint just snapped..

[clivehorridge]

Not genuine karlos?

I'm not sure this problem should be viewed as a war between good and evil. IMO, the only thing that can cause the taper pin to shear off is a seized ball joint, and irrespective of manufacture, the only cause I can think of is rust in the joint.

Water can penetrate any joint, regardless, and the rest is a matter of time.

I'm convinced mine was genuine, yet 19 years old at the time of failure. I don't care how good LC's are supposed to be, at that age, consumables will be failing for one reason or another. Again JMHO.

I've decided on a mission, once a year to crack all the tapers and check the joints are moving freely. After reassembly, check them with a breaker bar for play.

 

[Dave2000]

I see the dry taper as the cause, having seen many accidents where the steering has taken a severe impact, and the tapers always seem to be intact. My new parts have greasable joints, I am an avid prop shaft/CV knuckle grease checker anyway, so to put a squirt in the ball joints will add another few seconds while under there.

regards

Dave

 

[frank rabbets]

Were they Toyota ones Karl ?

 

[karl webster]

Not genuine karlos?

No not genuine. I priced genuine but they were a small fortune and I couldn't bring myself to paying it. I have loads of good second hand ones so didnt want to pay toyotas price although I wanted genuine.

I value Westcoasts opinion and they fit the ones I have to trucks they work on so that's good enough for me.

 

[chapel gate]

dave, clive, I hear what you are saying, but im confident if I had replaced with Toyota this would not of happened. as I have said these things should not snap under normal use, there life comes to a end when they develop play, this play can easily be felt by hand, no bar is needed.

to get me back on the road asap I had a second hand one off karl, there was no play in it and it was full of grease. id rather have a second hand oem than new pattern part, and It will be staying on until it develops play.

 

[clivehorridge]

dave, clive, I hear what you are saying, but im confident if I had replaced with Toyota this would not of happened. as I have said these things should not snap under normal use, there life comes to a end when they develop play, this play can easily be felt by hand, no bar is needed.

to get me back on the road asap I had a second hand one off karl, there was no play in it and it was full of grease. id rather have a second hand oem than new pattern part, and It will be staying on until it develops play.

There was no play in my Toyota joint CG when it's life came to an end, maybe a rare thing, but it was seized solid. Can't really explain why, it's just a fact.

I would like greasable units on mine....

 

[chapel gate]

im not doubting what you say clive. im beginning to think no grease was put in at the factory? come on, a few years and about 30000 miles, its nothing.

I find the seizing of the joints interesting, mines a daily driver, you wouldn't think it would have time to seize, its not just sitting there week after week slowly rusting is what I mean. I would of thought play would develop due to lack of grease before the seizing occurred. mine wasn't completely seized, I could still move it with some force back and forth with my thumb.

 

[frank rabbets]

Every time a piece of metal is stressed it is a bit weaker afterwards and will eventually break. Although the distance from the centre of the ball to the part where the taper enters the arm is short it is still experiencing a bending stress and will eventually fail. Calculations are fairly simple especially as the exact nature of the metal used is known. Work out the worst case scenario for 1million miles of off road and then multiply by say 5 and you can arrive at a very safe design.

One of the clocks I built has a pendulum suspension high carbon steel flat spring 3/4 inch long 1/2 inch wide and .002 inch thick. The pendulum weighs 15 kg and moves through 3 degree swing. There are 84,600 swings in a day. I needed to know if the spring would last a reasonably long time. I knew someone at British aerospace and he dialed the numbers in to his computer which gave the answer in 3 seconds 185 years !!!

 

[chapel gate]

"Calculations are fairly simple especially as the exact nature of the metal used is known. Work out the worst case scenario for 1million miles of off road and then multiply by say 5 and you can arrive at a very safe design"

that's my point really frank, the joint should be over engineered enough to overcome any amount of seizure, other than virtually welded. due to lack of lubrication to the point where play would develop through abrasion of the metal?

 

[clivehorridge]

im not doubting what you say clive. im beginning to think no grease was put in at the factory? come on, a few years and about 30000 miles, its nothing.

I find the seizing of the joints interesting, mines a daily driver, you wouldn't think it would have time to seize, its not just sitting there week after week slowly rusting is what I mean. I would of thought play would develop due to lack of grease before the seizing occurred. mine wasn't completely seized, I could still move it with some force back and forth with my thumb.

Confuses me too CG, mines a DD too, and although the steering is as smooth as silk now, I didn't notice it feeling seized, stiff or otherwise untoward.

It went with a hell of a bang when it let go, but as Frank has said, the stress fracture faces showed that it had been cracking for some time, with some rust in one side of the fracture,mash owing its age from an origin point.

Those pins are massive at the thick end where it broke, yet 380k km and 19 years, it's quite a lot to ask of a stressed pin... the seizure was just the last straw...

 

[frank rabbets]

CG yes I agree I expect the pin is over engineered.

I expect one could have a bad batch?

My friend with a 2 year old diesel Maxda has had a new camshaft, vacuum pump and turbo due to a poor batch of camshafts which wear and pass fine particles round the engine. There are pics on their forum. I don't know why the oil filter did not stop the particles. I assume contaminated oil would just drain off to the sump to be refiltered?

 

[Dave2000]

Having no grease added (or very little) during manufacturer is a very real possibility Mike. All products (not just vehicles) are being seen made from poorer quality materials, and assembled with cheap labour. IME, the general wear pattern from new is:

Outer rubber starts to deteriorate, letting grease out (compression from movement), if in a wet region, water gets in and clags with the grease, metal to metal contacts start to occur, wear is normally shown by slop in the joint. In dry regions the split rubber attracts dust which ends up in the joint and the grease dust combination make a grinding paste, again slop is the normal wear indicator. IIRC I have only seen this perhaps once or twice where the joint was completely dry and rusty, both in the UK and both were greasable joints.

It is feasible that as grease wears and metal to metal contact happens then again wear takes place. Quality of materials (including grease) correct clean assembly, and the design/fitment of the rubber seals dictates the life of the joint. My little Corsa van just passed it's regular six month MOT, a note of dust covers on steering joints deteriorating was added, I had checked the joints, and one had a little play but ordered both. The rubbers were not that bad but they are pretty strict over here. Rear brakes had a warning as well, over 20% imbalance but under 30% so no fail.

So back to CG's failure. It would appear that water ingress is clearly the cause of the rust, and lack of grease/water tight boot allowed the water in and caused the joint to fail.


My recent swapping of drag links (now on my third one in under a month) shows each had some grease in and took just three or four of pumps with the gun before the rubber boot started to swell.

I would guess CG's joint was made on 'POETS' day?

regards

Dave

 

[frank rabbets]

If you don't use a car much and the joints are dry of greease and rusty they will seize up quicker.