Metric versus UNF and my nightmare day

[Brakebuster]

so. i'm replacing some worn components on one of our fellow members car, this involves new stub axles and lower hub carrier ball joints on the front suspension , although a fairly straight forward process, the size and tightness of some of the nuts and bolts means a lot of knuckle bashing and sweating..........

this leads me onto the problem ,


the lower ball joint seal had failed, letting the weather into the joint, this then resulted in a nasty squeal when turning the steering wheel , on a 1990 car i would expect its on its second or maybe third ball joint from regular service intervals .

with a high quality ( non Jaguar ) lower ball joint ready to be fitted , i tried the original nut as they dont come with the balljoint, hmm , doesn't fit , i hadn't bashed or heated it up , so shouldn't be a problem , tried again , hmm , went to my storage bins, and hour later with all the nuts and bolts spread on the floor i still can't find one that fitted , the original nut did start but soon bound up , so i compared the ball joint thread to the old one, looks the same, a fine thread , must be UNF , but what size ?
the original nut was defiantly a metric nut as it had a blue nylock insert , ( UNF have white inserts ) and must have been forced on by the previous ' ahem' mechanic stripping the threads

i pulled my garage to bits trying to find one...but no luck , i had UNF but not big enough..........got on the phone to the father in law and he told me about Allcap , so i jumped in my company car and went to get some

turned out i needed 9/16 UNF , span on like it grew there , go figure........

at 30p each they weren't expensive , but the right part is worth its weight in gold when needed ,

so a three hour delay to tighten one nut up ,

so what am i trying to say ?

well, the last person to fit the ball joint bodged the job for the sake of 30p , causing me a huge issue

but at least its got the right parts now,

just got to do the other side now

BB

[GordonJ]

You have to ask yourself, didn't the person notice that this nut was not fitting properly. I have seen this before and on asking I found that the so called mechanic or fitter had used a huge wrench and couldn't feel that some thing was wrong.
PS. JRT just through MOT yesterday with no problems.

[Brakebuster]

PS. JRT just through MOT yesterday with no problems.

that is great news indeed

i still miss her loads.............

BB

[dhdove]

Vince

I sympathise, I deal with BA and Whitworth as well as UNF UNC and metric......

...it's a minefield!

TonyS

[almcl]

The metric/unf confusion nearly did for a colleague of mine a few years ago.

Tony may well remember this, www.en.wikipedia.org/wiki/British_Airways_Flight_5390
But the root cause was metric bolts inserted into unf captive nuts...