Paul - xxx wrote:
> Dougal wrote:
>
>>Can you describe the nature of the failure?
>
> Bloody catastrophic matey, cata friggin' strophic ... ;)
>
>>Is it the bearings or the
>>bearing housing/yoke? If the bearings, how did they fail? What does
>>the grease look like when you disassembled the UJ.
>
> Pics on Flickr ...
> http://flickr.com/photos/35295373@[EMAIL
PROTECTED]
> http://flickr.com/photos/35295373@[EMAIL
PROTECTED]
it's broken!
> Looks like 'cheesy steel' might have been right .... or maybe a roller
> failure chewing it up. All other ends look fine, greased OK, indeed
> this one looked well lubed, it was just dug away ... ;)
All sorts of possibilities - roller failure, missing roller(s), heat
treatment failure in manufacture etc.. We'll never know.
>>What sort of grease are you using? Does it contain Moly Disulphide?
>
> Castrol LM .. dunno about the Moly. Any recommendations?
Castrol LM (the yellow stuff) doesn't contain Moly.
Just an observation that highly loaded rolling element bearings
lubricated with a Moly grease can fail as the rollers may skid rather
than roll. The whole can then get rather warm and the end is not long in
coming.
Not an issue here.
>>These are UJs with grease nipples. When greasing do you ensure that
>>clean grease comes out at all bearings?
>
> Yup.
I think that last night's exchanges probably explain the likely cause. I
suppose that it is now a case of wait and see. Good luck!
>>Is there any vibration? All talk of bent shafts, incorrect UJ
>>orientation etc. is unlikely to be the cause without vibration also
>>being evident.
>
> You're right, the only vibration occurred when the UJ had already
> failed, the prop is absolutely fine. Just tried it out after replacing
> UJs and all is well again at any speed or condition.
>
>>When you compress the shaft does it stay compressed when you let go
>>or does it spring out again?
>
> Stays compressed.
It can also be affected the other way: pull it out and it is 'sucked'
closed again.
This was to check that there was a vent hole in the sliding ****tion. If
air can't enter and leave freely there can be end loads on the UJs which
they are not intended to take. Sliding joints which don't can have a
similar and even more obvious effect. UJs and bearings either side of
the shaft can be affected by these problems.
>>Is the shaft too long? Disconnect one end and fully compress the
>>shaft - how much clearance do you have?
>
> Loads, about an inch, maybe inch and a half, maybe a bit more.
More than enough. Just to confirm that the wrong shaft had not been
fitted.
>>Off-road use does tend to result in a much shorter life for UJs
>>whatever you do with them.
>
> Heheheh, I'd tend to agree with that ... ;)
>
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