Gazza Posted January 23, 2004 Share Posted January 23, 2004 Scruffy, I'm a bit late to this discussion, but I have to say that the diff in the superb pic that you posted isn't an LSD, I'm 99.9% sure. If it had an LSD you wouldn't be able to see the small internal bevel gears because they'd be buried within the LSD unit The LSD unit takes up the whole of that centre space and in fact becomes the carrier for the crownwheel. I have a plate type English LSD unit in my SE but the appearance is much the same whether its a quaife ATB, plate type or viscous type: So its seems you might not have an LSD if you can see the internal bevel gears ... Quote Link to comment Share on other sites More sharing options...
Blatman Posted January 23, 2004 Share Posted January 23, 2004 Scruffy *does* have an LSD, trust me The one in the picture may not be, but as I said before, I believe the non slip gubbins is nothing like the ATB or clutch packs of the "normal" LSD's....... Quote Link to comment Share on other sites More sharing options...
Gazza Posted January 23, 2004 Share Posted January 23, 2004 ..sure, I can only comment on the one in the pic Would like to see the inside of the LSD version tho, just out of interest, if any one has a pic handy .... Quote Link to comment Share on other sites More sharing options...
Blatman Posted January 23, 2004 Share Posted January 23, 2004 Me too. I've never actually had one apart, but I've heard from many sources that it does indeed look almost like an open diff. Sadly, the XR4x4 Haynes manual doesn't have any pictures of a naked viscous LSD, otherwise I'd have put them up. ..sure, I can only comment on the one in the pic Er.... So its seems you might not have an LSD if you can see the internal bevel gears ... Quote Link to comment Share on other sites More sharing options...
Ian Podmore Posted January 23, 2004 Share Posted January 23, 2004 This picture appears to have come from this website. Apparently the LSD parts are enclosed in the crownwheel assembly out of sight, but the picture is indeed a LSD version. Must get around to fitting mine sometime soon. Edit - the output shafts are difficult to turn independantly, as the diff is never totally free. Quote Link to comment Share on other sites More sharing options...
conibear Posted January 23, 2004 Share Posted January 23, 2004 My IRS diff is brand new from Ford with a label marked lsd, I have a receipt from WF marked lsd. If I gently drop the clutch from a standing start both rear wheels spin, enabling me to do a doughnut. This diff is stiff to rotate by hand and yes it has lsd oil in it and no its not noisy. My friends cateringvan is stiff as well. I dont know if this is relevant but my previous non lsd live axle diff was as loose as a goose. I could not do a doughnut from standing start. If this not relevant fire away Quote Link to comment Share on other sites More sharing options...
mark.anson Posted January 23, 2004 Author Share Posted January 23, 2004 Thanks for the relies chaps but what I really wanted to know was which ratios were commonly fitted to which cars. Quote Link to comment Share on other sites More sharing options...
Mark Stanton Posted January 23, 2004 Share Posted January 23, 2004 Will either most probably be a 3:62 or 3:92 Try and find a 3:92 if poss Quote Link to comment Share on other sites More sharing options...
Blatman Posted January 23, 2004 Share Posted January 23, 2004 3.62 to 2.8/2.9 XR4x4's. They are *ALL* LSD's. 3.9 to 2.0l 4x4's 3.36 to Sierra Estates Not sure what Granadas had in them.... Apparently the LSD parts are enclosed in the crownwheel assembly out of sight, but the picture is indeed a LSD version. I said that yesterday..... This diff is stiff to rotate by hand and yes it has lsd oil in it and no its not noisy. If you have a bog standard Ford LSD, or a Quaife ATB, you DO NOT need LSD oil. Ordinary EP90 is what to use. LSD oil is for use specifically with clutch type diffs. I don't think you'll do any damage, but if it was me, I'd change it...... Viscous and ATB's are silent in operation. Clutch type LSD are generally audible in use, and can be positively intrusive at walking pace...... It's stiff because it's new, and like Ian says, you'e also turning the viscous pack. You may also find the brakes normally drag a little....... I could not do a doughnut from standing start. If this not relevant fire away Relevant, because on a non LSD, once the unloaded wheel can't overcome the grip of the loaded, non spinning wheel, the donut stops. It's rare to get beyond 180 degrees from a standing start. With *any* LSD fitted donuts are a simple matter of throttle control, once the clutch is out....... Quote Link to comment Share on other sites More sharing options...
scruffythefirst Posted January 23, 2004 Share Posted January 23, 2004 I can confirm the diff in my avtar (from mr B's sierra) looks exactly the same as Tims ( the picture i posted earlier). You can most certainly see the bevel gears in both. I can't take a pic of it cos i'm 120 miles away and I have no digital camera - sorry. Scruffy Quote Link to comment Share on other sites More sharing options...
conibear Posted January 23, 2004 Share Posted January 23, 2004 Edit - the output shafts are difficult to turn independantly, as the diff is never totally free. This is why I stated an lsd is stiffer to rotate than non lsd I'd agree but wish to add the input shaft is even stiffer than just one output shaft. When lubricating the my lsd, Westfield, Ford and Hardy Transmissions only recommended lsd oil and NOT standard stuff, so I'll go with them on that one Quote Link to comment Share on other sites More sharing options...
Blatman Posted January 23, 2004 Share Posted January 23, 2004 Sadly, they're wrong........if you like, I can scan and mail you either the Haynes XR4x4 manual info, or Ford's own Sierra Cosworth manual specs for oil in Ford viscous LSD's. And your stiff diff theory is wrong too. The diff only starst to limit slip once a certain torque load has been reached. Up 'til that, the diff is effectively open. The minimum torque load for a viscous diff, according to the manual, is 22ft/lbs. I would imagine a new diff to be up around 30-40ft/lbs. The upper tolerance is 52ft/lbs. You cannot generate 22ft/lb's by spinning an unloaded road wheel with the car jacked up, unless you are doing the prescribed LSD efficiency test, which involves a torque wrench and some pretty swift movement. Quote Link to comment Share on other sites More sharing options...
scruffythefirst Posted January 23, 2004 Share Posted January 23, 2004 Any chance of posting (or mailing me) the test? So i can tell if you've sold me a Sh*tter Scruffy Quote Link to comment Share on other sites More sharing options...
stu999 Posted January 23, 2004 Share Posted January 23, 2004 IME, the an LSD sierra diff is is tighter than a 'free' diff when holding the prop flange and turning an output shaft. But a viscous Sierra diff does not need LSD oil in it, 'ordinary' spec stuff is recommended by Ford (even in Cozzys). But I reckon the only damage done by putting LSD oil in a Sierra diff is to your wallet. Quote Link to comment Share on other sites More sharing options...
conibear Posted January 23, 2004 Share Posted January 23, 2004 Sadly, they're wrong........if you like, I can scan and mail you either the Haynes XR4x4 manual info, or Ford's own Sierra Cosworth manual specs for oil in Ford viscous LSD's. And your stiff diff theory is wrong too. The diff only starst to limit slip once a certain torque load has been reached. Up 'til that, the diff is effectively open. The minimum torque load for a viscous diff, according to the manual, is 22ft/lbs. I would imagine a new diff to be up around 30-40ft/lbs. The upper tolerance is 52ft/lbs. You cannot generate 22ft/lb's by spinning an unloaded road wheel with the car jacked up, unless you are doing the prescribed LSD efficiency test, which involves a torque wrench and some pretty swift movement. You maybe right but my diff is stiff Stiffer than my previous non lsd. But I agree I expect it to loosen up but not that much. It's a 4.09 which is not that common. I've only installed the oil advised. Why is it then these oil enhancing agents, can't think of their name at the mo, advise not to be used on lsd and new engines. Their products increases viscosity I believe, reducing friction of two metal surfaces. So thats the same principal here. Ian Quote Link to comment Share on other sites More sharing options...
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