Sealed Final Drive?

[prwatts]

I hope this has not been asked before.
Is the FD sealed? If I close it up hot, or cold, what is the consequence?
What should I do?
Thanks,
Peter

 

[autogs]

your question makes no sense to me im afraid ,would you care to refrase it,
how do you mean close it up hot or cold?

 

[prwatts]

Sorry - I hear the FD is sealed, it has no breather. Therefore if you close it up cold, when it heats up it might blow out seals. If you close it up when warm, does it just have a bit of a low pressure inside or does it draw in air (and maybe dirt) through the seals.
I just wanted to find out what the common wisdom was.
Thanks Peter

 

[GrinningGSer]

A good question. I don't know the answer. Is there a breather hole ? If not, how do the seals cope with temperatire changes?

 

[TeaPig]

Only the latest FD's have breathers. Old ones do not.

The air inside the FD will expand a little when it's warm but this will only make a small increase in pressure within the FD. There's no point worrying about the air temp' when you 'close up' the drive as riding the bike generates heat within the FD so you can never 'match' the air pressure outside the bike for long

The increase in pressure will make the oil seals press slightly harder against the shafts but that's what oil seal are designed to do. The ones on the crankshaft for example hold back the pressurised oil from the oil pump which is many times higher than that within the FD

 

[bisbee]

Sorry - I hear the FD is sealed, it has no breather. Therefore if you close it up cold, when it heats up it might blow out seals. If you close it up when warm, does it just have a bit of a low pressure inside or does it draw in air (and maybe dirt) through the seals.
I just wanted to find out what the common wisdom was.
Thanks Peter

The latest final drives have a breather and are meant to be drained and refilled with new oil periodically yours will be one that was designed to be sealed for life but is likely to fail however it is possible and recommended that you change the oil in yours if you do a search on here you should find out how to do it

 

[prwatts]

Thanks everyone - I will take it that I just drain the oil and refill at ambient.

 

[MIKA]

Thanks everyone - I will take it that I just drain the oil and refill at ambient.

The only difference is you now only put in 180ml of oil compared to the original fill which would have been 220ml.

 

[prwatts]

Must it be precisely 180 ml or do you fill till it overflows?

 

[Kremmen]

It is only a filler plug & not a level plug...
You will have to measure it out first before putting it in, or do as i do use a syringe.... i have a 50ml one, place a 75mm piece of screen washer pipe on the front of it and away you go
If the wheel is off it will make it easier.

 

[prwatts]

Many thanks

 

[Kremmen]

The latest final drives have a breather and are meant to be drained and refilled with new oil periodically

Good point, i had a new FD fitted earlier in the summer as the bike has now been laid up for the winter i decided to drop the FD oil & replace it.

To be honest i was taken aback that the oil was very dark in colour & when i emptied the drain tray the bottom of this was covered in a film of what appeared to be dirt??

Now, i thought that dealers are suppose to be adding SAF-XO oil...or am I'm mistaken, this was very dark in colour where the new oil is a light golden,as only 800mls have elapsed since it was fitted i have to ask myself..

Did they use Castrol SAF-XO
The film at the base of the container.. was it debris drawn in through the breather, or had a additive been added to the FD.

I will be asking the dealer tomorrow.

 

[prwatts]

I will be very interested to find out.