LSD Tests

[Frenchy]

No not drugs !!! flowers attcking you and shit.......... took my wheels off to be taken for a refurb today and span the offside rear, nearside rear was stationary i beleive standard diff opposite wheel would turn in the opposite direction.
Your assistance please.

Cheers.

[eko]

Standard open diff and the other will rotate the opposite way.
LSD both wheels rotate the same way!

[Frenchy]

Cheers EKO is mine fooked then as no movement on the opposite wheel ???

[eko]

Put it in gear then try it

[Speedtouch]

My 320i's open diff (3.64:1) is like this too - no movement on t'other wheel. Still works OK

[billgatese30]

when both wheels are in the air, then an open diff will rotate the wheels in diferent directions, an LSD ewill both spin the same direction

when only one wheel is in the air, open diff will allow wheel to spin, LSD will not allow single wheel to spin

[snoops]

or you could just put it in first gear, floor it and look behind for a number 11

[OllieB]

Pull over on a grass verge (muddier and boggier the better) so both nearside wheels are on the grass, then do a fast start. If you don't get anywhere very quickly but the revs are high, then you nearside wheel is spinning and you don't have an LSD.

[Frenchy]

Snoops,
Nee wheels their away getting re-furb!

[snoops]

[forty]

Pull over on a grass verge (muddier and boggier the better) so both nearside wheels are on the grass, then do a fast start. If you don't get anywhere very quickly but the revs are high, then you nearside wheel is spinning and you don't have an LSD.

& you get stuck in the shit

[Conrad]

And you flick lovely soggy mud up inside the wheel arch and provoke plenty of tin worm. Lovely.

[RB5_245]

when only one wheel is in the air, open diff will allow wheel to spin, LSD will not allow single wheel to spin

A limited slip does allow one wheel to spin on it's own, just transfers a %power to the non spinning wheel. Otherwise it would be a locked diff

[jaistanley]

Jack the car up, put in gear and re-try.

If it is hard to turn the wheel but the other stays stationary or rotates in same direction you have an LSD.

Rotating opposite (easily) is an open diff.

Jai

[Ant]

If the diff is an LSD, jack up one rear, leave out of gear, take the H/brake off and see if you can rotate the wheel in the air, no spin= LSD, spin = open/fubar LSD

you could work out the torque required to turn the wheel, so 170 lbs/ft x 25%= lsd slippage amount.

Maths are sound-ish

[billgatese30]

when only one wheel is in the air, open diff will allow wheel to spin, LSD will not allow single wheel to spin

A limited slip does allow one wheel to spin on it's own, just transfers a %power to the non spinning wheel. Otherwise it would be a locked diff

yes, but just trying to spin it by hand is quite difficult

i was trying to explain it as simple as possible, otherwise it may have seemed to be confusing to those who are not mechaincally minded enough to realise that it allows a 25% lock up (assuming its a standard sport diff in good nick)

[Geoff]

when both wheels are in the air, then an open diff will rotate the wheels in diferent directions, an LSD ewill both spin the same direction

when only one wheel is in the air, open diff will allow wheel to spin, LSD will not allow single wheel to spin

I believe this is wrong. I had my old car up in the air with one wheel down and put it in first with the wheel spinning so i could take the burr off the discs.

[RB5_245]

I just read your post in the context it was meant Chris

I originally read it as an lsd allows no slip while driving. Whoops, my mistake.

[kam-325i]

span the offside rear, nearside rear was stationary.

Driveshaft dragging on exhaust ? Dose the same on mine.