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Is this 7 or 7.5inch????
charlierevell - 19/3/08 at 06:09 PM

Hi Guys,

What diff do you think this is...

DIFF

Would it fit a Dax rush previously with a 2l EFI pinto and now with a cossie lump???

twybrow - 19/3/08 at 06:11 PM

7.5" for the cosworths. I think you would want a diff from an XR4i (or is it XR4x4?!)...

Syd Bridge - 19/3/08 at 06:19 PM

I've said this every time this subject comes up...

Sierra 4x4's came with 7" and 7 1/2" diffs.

I've had three come through my hands in the last ten years, and all had 7.5" diffs. I've still got one set of running gear complete, and it is definitely a 7.5" diff.

Ford in their wisdom, put in what they had to hand on the day, as it appears.

And Cosworths came with 7.5" diffs, except for the RS500 and better, which had 9", same as GpA.

Cheers,
Syd.

I've got a 7.5" Cosworth diff in the shed, if anyone is wanting one.

[Edited on 19/3/08 by Syd Bridge]

charlierevell - 19/3/08 at 06:30 PM

Just interested as a mate has bought it for his Rush and I'm not sure it will fit!

locoR1 - 19/3/08 at 07:21 PM

That looks like a 7” to me on the 7.5” diff the top mounting is solid the 7” its hollow in the centre of the mounting, when fitted you can see the bolt running through the centre of the mounting!

SALAD - 19/3/08 at 07:25 PM

Ditto what he said ^^^^^

eznfrank - 19/3/08 at 07:27 PM

I have a 7" LSD 3.62 off an XR4x4 and I would say is the same as mine.

IDONTBELEIVEIT - 19/3/08 at 07:33 PM

7" deffo Rescued attachment DSCN1549.JPG
Rescued attachment DSCN1549.JPG

TOO BADD - 19/3/08 at 08:00 PM

Believe you measure the width of the casing at each end where the long bolt goes in at the top which should be either 7 or 71/2 inches

chris_harris_ - 19/3/08 at 08:49 PM

Looks very much like a 7" to me. And mine which came out of a cosworth 4wd) is a 7" lsd, so who knows what they where thinking when they bolted them all up!

MikeRJ - 19/3/08 at 08:59 PM

quote:
Originally posted by TOO BADD
Believe you measure the width of the casing at each end where the long bolt goes in at the top which should be either 7 or 71/2 inches


That's a bit of a fluke if it does as the size refers to the crown wheel.

mcerd1 - 19/3/08 at 09:35 PM

as above its definatly a 7"






quote:
Originally posted by Syd Bridge
I've said this every time this subject comes up...

Sierra 4x4's came with 7" and 7 1/2" diffs.

I've had three come through my hands in the last ten years, and all had 7.5" diffs. I've still got one set of running gear complete, and it is definitely a 7.5" diff.

Ford in their wisdom, put in what they had to hand on the day, as it appears.

And Cosworths came with 7.5" diffs, except for the RS500 and better, which had 9", same as GpA.

Cheers,
Syd.

you must have got some weird 4x4's then all the ones I've ever seen (inc cossie 4x4) have been definatly 7"

I thought the main problem with 7.5" on the rear of a 4x4 was that they didn't make any front ratios [6.5"diff] to match

but then over the years ford have done all kinds of weird things to use up the spare parts....

Liam - 20/3/08 at 12:03 AM

Of course I wouldn't dispute that Syd could well have picked up 3 4x4s with 7.5" rear diffs, but they'd be the only three out there... in the entire world! Everyone else in the history of humanity has found a 7" diff on the back of their 4x4s, whether XR or cossie . You're right mcerd1 that a 7.5" would be 3.64:1 rather than the 3.62:1 to match the front diff. That said, the resulting approx 0.6% speed difference between the front and rear axles helping to keep the centre diff VC toasty probably wouldn't have stopped Ford shoving a few wrong diffs on if they felt like it on a friday afternoon (though it was only a 0.9% speed difference 'design fault' that killed early Freelander centre VCs, normally locking them solid giving rise to horrible tyre wear, and after that transmission failure).

Oh as above that's a 7" - easily identifiable by the hollowed out top mount. So that seller is evil and lied about it coming off a 2WD cossie.

Liam

mcerd1 - 20/3/08 at 10:21 AM

quote:
Originally posted by Liam
a 7.5" would be 3.64:1 rather than the 3.62:1 to match the front diff.


or a 3.91 [7.5"] instead of a 3.92 [7"]
(the only 4x4's to get 3.92 ratio's were 2.0 XR4x4's)



- from that ebay description I wouldn't trust anything

its defiantly a 7" with 100mm bolt-on shafts, but the rest is anyone's guess

so I'd want to check the ratio and the LSD claim myself before bidding

----------------------------------------------------------------

anyway, to answer the last part of the original question:

If the Dax in question has a sierra diff at the moment then any 7" or 7.5" diff should fit (assuming its a DeDion - if its an IRS I think thats still true, but I'd have to check)
its just a case of making sure you have the right hubs and shafts to match, but I assume that he'd rather keep the shafts and hubs he's got if he can

chances are that a 2.0 pinto car will have the 2.0 pinto diff, so it will most likely be a 7" with push-in shafts and drum brakes if it all came from a sierra, but it could be bolt-on, or 7.5" - so best to check if your/ he's not sure

btw - tell your mate to get himself over here: http://forum.rushowners.co.uk/phpBB2/ and say hello (if he hasn't already)

-RD

[Edited on 20/3/08 by mcerd1]

[Edited on 20/3/08 by mcerd1]

charlierevell - 20/3/08 at 11:16 AM

Well ATM its got Discs on the back not drums. Havent looked into it any further than that but ill pop over and have a look at it over easter if its arrived.

Syd Bridge - 20/3/08 at 11:32 AM

The cars I had were all Island cars, if that makes a difference.

First two were 2.8's, the last a 2.9.

I've still got the last running gear in a car in my back yard, if anyone wants to have a look. And definitely 7.5".

Cheers,
Syd.