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Discussion Starter · #1 ·
I have read it is possible to determine if I have an LSD by looking inside the oil fill plug on the diff. However it's nigh on impossible to see anything at all.

Before I buy a boreoscope, is it possible to poke one in the oil fill hole and see some feature that will determine if it's an open or LS diff?
 

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Hiding from the Ayatollah or making Full Metal Jac
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The easiest way to tell if you have an open differential is to jack rear of the car so both rear wheels are off the ground and spin one of the rear tires. If the other wheel spins in the opposite direction, you have an open differential. If it spins in the same direction, you have a limited slip differential.

Also get some photos of the diff, that can help with identification.
 

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Discussion Starter · #3 ·
I believe the jacking and spinning the wheels doesn't work to ID the diffs because the LSD relies on the opposite side having some traction
 

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Discussion Starter · #4 ·
Mines def a MK1 1.8 diff, finned with the full half shafts. My car was a 1.8i or si, 97, so there's a good chance it does have one..but I want to confirm 100%
 

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Banish a little rust a day people
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The easiest way to tell if you have an open differential is to jack rear of the car so both rear wheels are off the ground and spin one of the rear tires. If the other wheel spins in the opposite direction, you have an open differential. If it spins in the same direction, you have a limited slip differential.

Also get some photos of the diff, that can help with identification.
This only really works with a clutch type LSD and even then isnt 100%. A torsen will spin both in opposite directions, as will an open so it's not much help.
 

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Happily expanding the To Do list since 1997
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A Mk1 1.8 will pretty much certainly either be open or torsen. They both behave the same if you jack the back up and turn one wheel so you can't tell them apart that way. I have put a borescope* into the fill plug of my current one and was able to see (by turning a wheel to rotate the diff) the clusters of small straight cut and spiral gears indicating it's a torsen.

*A cheapo £15 USB endoscope from Amazon or eBay.
 

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Discussion Starter · #7 ·
A Mk1 1.8 will pretty much certainly either be open or torsen. They both behave the same if you jack the back up and turn one wheel so you can't tell them apart that way. I have put a borescope* into the fill plug of my current one and was able to see (by turning a wheel to rotate the diff) the clusters of small straight cut and spiral gears indicating it's a torsen.

*A cheapo £15 USB endoscope from Amazon or eBay.
Great stuff I will give this a go!
 

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Happily expanding the To Do list since 1997
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Slight topic drift: those cheap endoscope are a bleedin' life saver. (When you drop a 6mm Allen key bit and it falls straight into a mate's Katana engine and clatters down the timing chain channel. The clip-on magnet you can fit right in front of the camera is perfect for retrieval.)
 
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