Sierra Diff fill plug size

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Dan R
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Sierra Diff fill plug size

Does anyone know the size/thread/spec for the Sierra diff fill plug? (Currently have a second diff with no plug at all)

I want to get a magnetic one but have no idea what size it would be.  I can see the 'Gold' magnetic plugs have codes so any help would be appreciated! 

Jonathan Kay
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"M20 x 1.5"

Jonathan

Geoff Brown
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M20x1.5 is indeed the size for the BMW diff but I would hazard that it would not be for the Sierra diff on a R500. Knowing the assortment of AF & Metric threads on cars of the R500 era the Sierra diff plug is likely not to be be metric.

 

 

Dan R
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Thank you Jonathan!

R500sv

'Bravery is being the only one who knows you are scared' 

Dan R
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Thanks Geoff, .... how did i know this wasn't going to be straightforward!!   Rofl

Surely the standard Sierra diff casings all have the same fill plug? or am i being extremely naive ?? 

R500sv

'Bravery is being the only one who knows you are scared' 

Jonathan Kay
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If you're searching outside the Caterham world beware... there are several different Sierra diffs.

That was the only reference that I could find in the archives. That surprised me as I thought that various threads had mentioned various threads.

Please let us know what fits.

Jonathan

Wrightpayne
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My money is on it being metric!!

The original OEM plug has a magnet in/on it. Seem to be available on line albeit £20ish :-0

I'm fairly certain the K series Caterham dry sump pan uses the same plug.

https://www.bearingkits.co.uk/FORD-SIERRA-DIFF-MAGNETIC-FILLER-PLUG/123.htm

Englishmaninwales
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Arrow Up Correct, same as the later K series DS sump.

Wrightpayne
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This thread (no pun intended) has some part numbers...looks like it was also used on the K series apollo tank!!

https://www.caterhamlotus7.club/forum/techtalk/bits-n-pieces-apollo-tank-fitment

Geoff Brown
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I do not mind being proved wrong but as an example my late 2012 Six Speed has a three eighth inch allen key recess in both fill & drain plugs. BUT the BMW diff has a metric fill plug both in thread & hex insert.

All in a metric chassis......well 95% of it any way !!

Dan R
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Having looked at the various links, it does seem like M20x1.5 is the favourite.  Either a branded one or the Ford original Thumb Up

R500sv

'Bravery is being the only one who knows you are scared'