What Limited Slip Diff's are available from the Sierra. I'm aware that 'the 4x4' has a LSD, but which model has one - the XR4, 'standard 4x4' or
Cosworth?
If I assume right that all those models are fitted with one, what are the differences between them (ratio's and casing/mounting)? and how do I stop
someone selling me a none LSD - do they look any different from the outside.
Thanks for any info received.
There appears to be two size of LSD fitted to the Sierra. It's the size of the top front mountings which you should check, there is 7 inch and 7.5 inch. I think the larger one was fitted to the Cossie spec cars, and also has a larger input flange. Easy way to check if LSD is by turning the input flange and the output flanges should both turn together in the same direction, if they turn in opposite then not LSD. The LSD I got looks just the same as the non LSD one. Suspect 7inch is most common, if self build you can choose which size to use but most spec 7inch. I think ratios differ between cars as also fitted to Granada. Think they range from 3.9 to 3.3/1.
*Alarm bells ringing*
To check if you have an LSD, you gently turn a drive shaft flange. If the other one turns the same way, you have an LSD. If it goes in the opposite
direction it isnt (but you probably worked that out already...) Turning the input flange (prop flange) should make them both turn the same way for
either diff. If it doesnt, leave it where it is, because if its fitted to your car, you will go round in circles....
They don't have to both go the same way with non-LSD - one can be stationary and the other will go twice as fast. That's the point - unlimited slip. But yes, one shouldn't go backwards.
Geoff, true one can be stationary, if held or stuck, but if is free it will turn the opposite way if non-LSD.
quote:
They don't have to both go the same way with non-LSD - one can be stationary and the other will go twice as fast. That's the point - unlimited slip. But yes, one shouldn't go backwards
quote:
Geoff, true one can be stationary, if held or stuck, but if is free it will turn the opposite way if non-LSD.
Yep, that's what I tried to say.....I think...(very badly)
One wheel can be held still while the prop shaft turns the other wheel only.....with non-LSD.
And, with the prop held still the wheels will turn turn opposite to each other with a non-LSD when you turn one by hand.
Damn....that sounds even more confusing...sod it...
Hello...
XR4i's didn't have an LSD as standard. All 4x4's do and they're all 3.62:1 as standard, granny 4x4s too. All 4x4s, even cossie, are 7". 7.5" LSD's
are found on 2WD cossie and 24V scorpio as standard - probably be some on 12V V6 grannies/scorps too.
7" are most common and fine for the average Locost. 7.5" are popular with Dax Rush owners and their big V8s.
Liam
Oh whoops - forgot 2 litre 4x4s, which have 3.92:1 diffs.
Well boys, I think we managed to simplify that one for him !!??
Thanks to one and all for that. Now know where I can source one from. And I think I know how to tell none LSD's and LSD's. To sum up (and hopefully
not cloud the issue further).....
If an LSD is sat in front of me, and I hold one drive shaft output, by turning the prop-shaft flange, I will feel resistence in the 'propshaft
rotation' and the held driveshaft flange will try to turn.
If it is a None-LSD and I perform the same test, then as I turn the propshaft, there will be no drive felt in the held drive shaft, no resistence
(apart drag of gearoil) and the unheld driveshaft will turn freely.
Is that a valid test, without having to remember, which wheels go in which direction, depending on which shaft is turned........ ??
Cheers!!
That sounds about right, but it's probably easier to just turn one of the output shafts and see if the other goes in the same direction or opposite
direction. An even better way would be to find out exactly how these things work, and then not only would you know how to tell what type it is, but
also how they do what they do.
One question of my own, but related, I know there are two different types of drive shafts/connections for LSD, and I seem to remember they may be
directly related to whether it's got disc or drums, so, can I have a breakdown of possible car/diff/driveshaft type/brakes please? I'm sure others
would find this helpful too.
One last questions, less related, but interesting none the less. How would you tell if it had an atb? And does anyone care to explain to me how they
work.
Kingr
Rightyoh, For 7" sierra all lsd diffs have lobro shafts, as do non lsd with disks. Drums use tripod shafts. For the avon its designed for drums and non lsd, but "according to chester sportscars" that I spoke to last week, if you want an lsd and disks you have too turn down the abs bit to fit through the hub carrier and switch sides with the callipers, ie trailing will become leading.