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Cosworth 4x4 rear diff question. Need a straight answer.

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Old 14-04-2014, 10:41 AM
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mbfordnut
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Default Cosworth 4x4 rear diff question. Need a straight answer.

Hi guys I know this is a repost and has been asked before but I need a straight answer all the google searches throw up conflicting results

Looking at a 4x4 7" rear diff for my sapphire my old unit was a quaife I now want a standard LSD.

My question to check an LSD unit I was under the impression you hold the input flange (prop) and spin a output (drive shaft) flange the oposite flange should also spin the same direction. Not oposite..

Is this true on a standard Cosworth LSD diff or are they different?

The 1 for sale the output flanges spin opposite ways but the guys adamant it's original via worth but I'm not 100% so thought id ask,

Also worth mentioning there's no tag on the rear case as that would give ratio and part number
Old 14-04-2014, 10:43 AM
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james kiely
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martin they should spin the same way as far as i know mate .if you spin the prop both shopuld turn the same way
Old 14-04-2014, 10:54 AM
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mbfordnut
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I think they would spin the same way on non LSD just by turning the prop as that's just spinning the crown wheel. Thought you had to hold that and turn the driveshaft flange to operate the LSD., it should be tough to do aswell, as I say just what I was always assuming but I'm not too sure now myself :-(
Old 14-04-2014, 11:34 AM
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crash_ash
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dont hold the prop, turn one driveshaft the other should turn the same direction
Old 14-04-2014, 06:22 PM
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Marc sierra
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If you don't hold the prop even an open diff could have the driveshafts turn the same way. The only way to be sure that it's an lsd is to hold the prop and turn one driveshaft, the other driveshaft should then turn the other way. But the harder it is to turn the driveshaft, the better the lsd is working. If the driveshaft turns very easily the lsd is worn.
Old 14-04-2014, 08:04 PM
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mbfordnut
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Haha conflicting answers, just like google search. Just wonder how many non LSD diffs are in cosworths :-(
Old 14-04-2014, 08:11 PM
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Caddyshack
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Send it to bara for a check, only buy on confirmation.
Old 14-04-2014, 08:38 PM
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Mark V8
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Handy link if the diff still has the tab

http://www.super7thheaven.co.uk/Sier...r_Differential
Old 14-04-2014, 09:02 PM
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Glenn_
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What an interesting web site that is.
Old 17-04-2014, 11:34 AM
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MrEngineerdat
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alternative answer i know... but it still describes an LSD
i read in the manufacturers build manual for an xr4x4 that if the prop is locked up and one wheel is jacked up you should have approx 40lb/ft of slipping force... that is to say, it'll be really stiff to turn but will give way when 40lb/ft of torque or more is applied to the hub.
hope it helps
Old 17-04-2014, 07:02 PM
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Marc sierra
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That matches what I said.
Old 19-04-2014, 09:55 PM
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Cilly-jey
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I have one coming off my old car in a week or 2, will check it out when it comes off.
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