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LSD or NOT lsd that is the question
Ricks-9r - 17/12/07 at 12:32 PM

how can i tell if i have a LSD fitted, apart from taking off the cover ? ,its a sierra diff with push in shafts ,it dont feel like a LSD diff as when jacked up the wheel spins freely & not tight to turn like other lsd,s ive worked on (my Skyline GTR & mates WRX) any help appreciated

2b_pablo - 17/12/07 at 12:43 PM

look at the ID plate. i think if there are 2 or more As in the middle part its an LSD.

or jack up and spin one wheel. the other should turn the same way.

someone posted a list of all the diff IDs in another thread.

2b_pablo - 17/12/07 at 12:44 PM

another way is to go to halfords car park and give it dixie on full lock

mookaloid - 17/12/07 at 12:51 PM

If when jacked up the wheels spin freely then it is an open diff.

The LSD takes quite some effort to turn the wheels.

I thought my wheel bearings were binding when I first built the car until I realised how it works.

The thing where you turn the wheel and look for the other wheel turning one way or the other is a red herring as both open and LS diffs work in exactly the same way.

Cheers

Mark

2b_pablo - 17/12/07 at 12:54 PM

ah np.

the ID is the best bet then imo.

mcerd1 - 17/12/07 at 01:24 PM

quote:
Originally posted by Ricks-9r
,its a sierra diff with push in shafts


I don't think there is a ford LSD with push-in shafts :? so its probibly an open diff, but the ID tag will help you work it out - see here:
http://forum.fordsierraclub.co.uk/viewtopic.php?t=5843&highlight=diffs

although it could have an aftermarket limited slip fitted (Quaife etc) the ID tag won't help with this, but its unlikley to have one

if the wheels are easy to turn in opposite directions, then its an open diff (or a dead LSD)

[Edited on 17/12/07 by mcerd1]

TimC - 17/12/07 at 01:27 PM

quote:
Originally posted by mookaloid
If when jacked up the wheels spin freely then it is an open diff.

The LSD takes quite some effort to turn the wheels.

I thought my wheel bearings were binding when I first built the car until I realised how it works.

The thing where you turn the wheel and look for the other wheel turning one way or the other is a red herring as both open and LS diffs work in exactly the same way.

Cheers

Mark


The best way if you don't have the ID tag is to try to turn the output flanges in the opposite direction to each other. If your 4-year old nephew could do it, it's open. If it takes quite a bit of effort then it's LSD.

Ricks-9r - 17/12/07 at 02:10 PM

well according to this its not an LSD as it has push in shafts

Push in type shafts

KC 3.14 7"
LC 3.38 7"
MC 3.62 7"
JD 3.92 7"
DA 3.91 7.5"

Bolt on shafts

BA 3.14 7"
GB 3.14 7.5"
DAA 3.14 7.5" LSD
FA 3.36 7.5"
AAA 3.36 7.5" LSD
AC 3.38 7"
CAA 3.38 7" LSD
BC 3.62 7"
BAA 3.62 7" LSD
AAA 3.64 7.5" COSWORTH (this has the same number as the 3.36 7.5" LSD BUT is ID'ed by 108mm drive flanges)
ADA 3.64 7.5" GRANADA COSWORTH
DC 3.92 7"
AA 3.92 7" LSD
GA 3.91 7.5"
ABA 3.91 7.5" LSD

thanks for your help

mcerd1 - 17/12/07 at 02:34 PM

quote:
Originally posted by Ricks-9r
well according to this its not an LSD as it has push in shafts


but on the plus side, push-in shafts are lighter

madteg - 17/12/07 at 05:53 PM

Any diff with two, AA in it is lsd , you cannot tell by rotation of driveshafts.

Wadders - 17/12/07 at 08:00 PM

I wouldn't worry too much if its not an LSD, the ford viscous LSD is set up for the much heavier doner sierra, pretty useless in a bec, i ditched mine in favour of a quaife unit, expensive but it works. And as said push in shafts are lighter.

Al.