cossie 7.5 diff ratios

[wight jr]

Anyone got info on what ratios you get for these diffs and where to get them.
Regards Graeme

[CNHSS1]

ive got the full ford list on my work pc, but this may help, PM or email me and i will sort all the info out if you need it

7,5 inch diffs, All v6. Sierra, Scorpio,s and 2wd Cosworth

3,91:1 some 2.0 Sierra's/Scorpio's

3,64:1, Still most used

3,36:1, Sierra 2,9 2wd, Scorpio (incl bug eye) 2.5TD

3,14:1 Sierra 2,3 Auto (could be on other auto models too)

4,27:1 Said to be on some frog eye Scorpio's (either 2.0 or 2.3, the other has 4,17:1 I believe

basically avoid the 4x4 rear diffs as they are 7"

above are ford OEM ratios, but they homologated a few other ratios but they are rare and mega bucks juts for a CWP. Theory is that the tooth size is smaller too so when you get nearer 5:1 they arent as strong, hence the reason ford produced the 909 rally 9" diffs for the rally cars.

most of the ford oem diffs from the above list are Non LSD, except the cossie variants and a short period of granada cosworth scorpio before they went to traction control and ditched the LSD.
All ford OEM are viscous pack LSDs and can be overheated and lose the 'tension' in the viscous pack. Less likely in a granada sourced diff as its less likey to be thrashed like a 2wd cossie.
DOME Motorsport in bromsgrove are ford trans specialists or ATM in essex who usually have quaife and plated variants and all CWPs on the shelf
HTH
Craig