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Xd fairmont ghia diff ratio

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Should be 2.78 from memory, could also depend on if it's a 4.9 or 5.8.

 

 

Edit: 4.9 got the 2.92 either manual or auto, 5.8 manual was 2.92, auto was 2.77 and some highway patrol cars got a very rare 2.53.

 

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The housing itself will tell you what series it is, unless it's a weirdo hybrid one (ie 75 series gears in 78 housing) Should be 0575 series with those ratios. You will find that on your tag, stamped on the centre somewhere and also on the gears themselves.

Like this:
b4f15864fdc1a30cdd089777d6d886f3.jpg

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Thanks, will just have to wait till he tells me the ratio,  only want the lsd for my ve val diff,   if its the 75 series i cant use it i  my 78 housing? Thats what someone told me? 

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It's been too long so all that info isn't fresh in my head. It can be done, it's just the issue of pinion spacing in relation to the crown. There is a thick shim to do this that goes between the inner pinion bearing race and the back of the gear. I think it's something like 120 thou.

I'll explain why: the difference between 75 and 78 housings is in the pinion depth, and is determined by how deep the step for the inner pinion bearing is machined. 75 has the pinion deeper into the crown, as the 75 crown wheel is smaller in diameter and the pinion needs to go deeper into mesh to meet it. Putting that shim in behind the pinion puts it into proper mesh with the crown and corrects the difference between housings.


There is an instance where there is a different carrier used, on the 2.77 diffs they had a greater offset on the crown wheel to allow for larger diameter pinion gear. This centre is only compatible with those gears. In some rare instances, they've used that weirdo carrier with 2.92 gears and have a big shim under the crown wheel to space it back across to where it normally would be.

All other centres should swap.

But 25 spline centres won't work with 28 spline axles. The holes are too small for the axle diameter.

Be sure to get the correct carrier bearings, as there are differences.

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So the guy has come back to me about this diff. Said is t is 2.9 ratio,  so that must be the 2.92 one, said it is lsd, so my question is, will this centre work in my ve valiant. 25 spline is what i have. 

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32 minutes ago, xwagon said:

So the guy has come back to me about this diff. Said is t is 2.9 ratio,  so that must be the 2.92 one, said it is lsd, so my question is, will this centre work in my ve valiant. 25 spline is what i have. 

i would assume so if it's a 302. V8. i'd imagine it could be 28 spline possible for a 351.

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My understanding was that 28 spline did not start till after the xf? And that all bw diffs before that were 25 spline.  And apart from the 2.77 ratio. All the centres and gears were interchangable. 

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31 minutes ago, xwagon said:

My understanding was that 28 spline did not start till after the xf? And that all bw diffs before that were 25 spline.  And apart from the 2.77 ratio. All the centres and gears were interchangable. 

 

i am 99% sure if they had 351s they got 28 spline axles and 4 pin pre XF. no XF would have got 28 spline to my knowledge. 

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