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misty
29th September 2010, 06:10 AM
Hi all
I have just taken del of sierra diff and all the parts with it
now, looking over the diff i can't see any codes letters numbers the tag has nothing on it
how can i find out which diff it is has anyone any ideas please
many thanks:(

mr henderson
29th September 2010, 06:25 AM
Hi all
I have just taken del of sierra diff and all the parts with it
now, looking over the diff i can't see any codes letters numbers the tag has nothing on it
how can i find out which diff it is has anyone any ideas please
many thanks:(


How about counting the number of turrns of the input flangethat are required for one complete revolution of the output shafts (averaged if it's different for each side)? Would that do it?

tex
30th September 2010, 10:14 PM
if you take the cover off the back there should be painted numbers on the crown wheel (think thats the big gear bit) :o)

mr henderson
30th September 2010, 10:23 PM
if you take the cover off the back there should be painted numbers on the crown wheel (think thats the big gear bit) :o)

If there aren't, and if he's got the cover off anyway, then if he can see, or feel with something, the pinion, he can just count the teeth on the pinion and the crownwheel, divide the latter by the former and get the ratio.

Easier just to turn the input flange and count the turns needed to get the outputs to turn one full revolution, though.

misty
2nd October 2010, 07:52 AM
Hello All
need help with this one if anyone can help

bought a sierra diff and shafts all no prob

on the diff no info at all tab is there but nothing on it

how do i find the type of diff ie 9

need help please

Trif
2nd October 2010, 10:24 AM
This might help you.
http://www.sierraclub.co.uk/mechanical-issues-f10/diff-types-t98.html

mr henderson
2nd October 2010, 11:54 AM
Assume you didn't like the answers you got here?

http://www.haynes.co.uk/forums/showthread.php?t=5109

Bonzo
2nd October 2010, 12:23 PM
The advice given in that thread is really the only positive way of telling your diff ratio ;)

There is a list of the different diff's fitted to the Sierra in the Haynes manual .... Not really the propper way to ID a diff that may not even be the one originally fitted to the car !!??

Sometimes you can give the ID tag a good clean with some sand paper, if not too corroded you may be able to read the markings.
That said, still not proof that that was the tag originally fitted ( More so if it has been sold as an hard to find low ratio one )

Counting turns/teeth is the only sure way .... Most of the time the ratio markings are still visible on the crown wheel but that would still assume that the diff has never been meddled with.

If you really need to know & none of the advice given, floats your boat, perhaps a visit to a gearbox specialist will put your mind at rest :) :)

misty
2nd October 2010, 02:45 PM
Thats super i will try all those

many thanks

misty
2nd October 2010, 02:53 PM
Hi All
i have managed to find numbers on this diff if anyone can help that would be great
85gg bc 382
4a 10u9 1266
f11/2
0046 a

i have not got a clue what these are
please help

Bonzo
2nd October 2010, 05:05 PM
As far as I know

85GG BC relates to a 3.62:1 dif ratio , Commonly fitted accross the Sierra range. :)

tex
3rd October 2010, 09:53 AM
3.62 diff. Which is a mid range ratio and most sierras used. Should be good to use

Bonzo
3rd October 2010, 12:44 PM
This was answered yesterday when you posted it :confused: :confused:

Here (http://www.haynes.co.uk/forums/showthread.php?t=5109)

I don't think you will get a different answer by asking the same question elsewhere on the forum.

If you have major concerns about your diff a little more background info would be helpfull :)

As it stands You appear to have a 7" sierra diff that has a ratio of 3.62-1 & is fine for the Roadster

AshG
3rd October 2010, 01:33 PM
I have merged all three threads into one as this topic is starting to get messy.

Ash

Hoybi
5th October 2010, 10:58 AM
I just found this on the "wide world winternet"
For those who still wonder how it works. They'll never have to ask again.


http://www.autojunk.nl/2010/10/hoe-werkt-een-differentieel

Hope this link works. ;-)

twinturbo
5th October 2010, 01:11 PM
That explains the Differential Drive which is one component of the final drive unit. the other is the Crown and Pinion gears that Provide the Drive ratio.

TT

Bonzo
5th October 2010, 01:27 PM
That is a fantastic bit of information :)

This film was made in an erra when information was given to you without blinding you with science :cool:

Should be mandatory viewing for youngsters at school :D :D

misty
5th October 2010, 06:50 PM
Tha is real good now anyone can understand
many thanks to all

seventhheaven
2nd December 2010, 12:48 PM
Hi,
A friendly man at the local ford dealer let me use his microfiche machine and I've managed to get all the part numbers, FINIS numbers, exploded diagrams etc for Sierra, Granada and Scorpios. I'm putting together everything I've found at www.super7thheaven.co.uk (http://www.super7thheaven.co.uk)
Hope that helps - It's a work in progress