S2 differential?

S2 differential?

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Discussion

Davewelly

Original Poster:

220 posts

164 months

Friday 20th May 2011
quotequote all
Hi guys,

My car just flew through it's mot but my mechanic mate reckons there is a bit of play I'm my diff. Just had both drive shafts replaced and although there us no leaks he thinks the diff could be the cause.
I've been searching to identify which diff I need but can't get a definite, does anyone know which one to use?

Cheers
Dave

Gerald-TVR

4,896 posts

197 months

Friday 20th May 2011
quotequote all
The search engine is your friend - nicked from a paost ketvrin

Heres a diff guide
To add to the list;
3.64:1 7.5" for the RWD Cosworth (with 108mm drive-flanges)
The Granada Cosworth 24v diff is the same as the 2WD Cosworth BUT with Sierra compatible 100mm drive flanges. and the 4x4 Cosworth is the same as the 2.8/9 Sierra's 4x4's and 2.0 DOHC 4x4 is 3.92:1 in a 7" diff
and some 2.0 RWD DOHC's are 3.91:1 in a 7.5" diff and finally some 2.3 diesels have a 3.14:1 7" (hens teeth)

Another way of knowing what diff you have is to look on the diff ID tag (little alloy tag bolted to the rear cover, top left hand side) Shown in the picture circled in red.
There will be some numbers/letters (look at the top row),
EG. 83BG MC 362
The 1st set (83BG) is the case type (7" or 7.5") as there quite a few codes its not worth looking, the esiest way to ID a 7" and 7.5" is to look at the top mounting. The 7" has one long bolt/nut and the 7.5" has 2 bolts.
7" on the left, 7.5" on the right.
Next is the middle code in this case its 'MC' which is an 'OPEN' type diff (NON-LSD) basically ANY diff with 2 or more "A" in the middle code will be an LSD e.g. "AA" or "ADA" any other letters without an "A" in the code IS an open diff.
Finally is the numbers, 362 which is (simply) 3.62:1 ratio.




AS you can see the 7.5" diff is big begger compared to the smaller 7" diff
Don't be put off by this as the 7" diff is a strong one (used in the 4x4 Cosworth remember) ALL the 7" internals are the same (except the ratio's and LSD bit) so even the basic 1.6 diff is bulitproof




The following diff are LSD. ALL 4x4 Sierra's and Granada's (2.8/9 and 2.0DOHC and Cosworth)
Most BUT not all 24v Cosworth Granada/Scorpio (upto approx 1994 are LSD, after that they are 'open' type because the Scorpio 24v had traction controll instead) All RWD COsworth Sierra (3dr, Saff, RS500)
Then you might find an LSD fitted as an option to any Sierra or Granada, but unlikely

Also look here http://www.sierraclub.co.uk/mechanical-issues-f10/...

Davewelly

Original Poster:

220 posts

164 months

Friday 20th May 2011
quotequote all
Great info, cheers

ketvrin

3,504 posts

209 months

Friday 20th May 2011
quotequote all
The important thing is to get a 7.5 inch Diff with 3.64:1 ratio and if you decide to go for an LSD make sure it has the 100 mm output flanges (not the 108mm)

the full story can be read on the FAQ's here...

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

K wink

Davewelly

Original Poster:

220 posts

164 months

Friday 20th May 2011
quotequote all
Great, cheers

magpies

5,129 posts

182 months

Friday 20th May 2011
quotequote all
I have a pair of spare diffs - one non lsd and the other with lsd

pm me if interested

Alan Whitaker

2,054 posts

182 months

Friday 20th May 2011
quotequote all
Hi.
I found this on a serch by a guy called mat
Push in type shafts

KC 3.14 7"
LC 3.38 7"
MC 3.62 7"
JD 3.92 7"
DA 3.91 7.5"



Bolt on shafts

BA 3.14 7"
GB 3.14 7.5"
DAA 3.14 7.5" LSD
FA 3.36 7.5"
AAA 3.36 7.5" LSD
AC 3.38 7"
CAA 3.38 7" LSD
BC 3.62 7"
BAA 3.62 7" LSD
AAA 3.64 7.5" COSWORTH (this has the same number as the 3.36 7.5" LSD BUT is ID'ed by 108mm drive flanges)
ADA 3.64 7.5" GRANADA COSWORTH
DC 3.92 7"
AA 3.92 7" LSD
GA 3.91 7.5"
ABA 3.91 7.5" LSD
The difference between the' A ' and the 'B' type is in the
method that the drive shafts are fitted to the differential unit.
The 'B' type differential units are a common fitment to the Sierra cars.

There are two sizes of differential unit. The large differential unit is
fitted to the Cosworths
and Granada, it measures 190mm across the top mounting faces.
The small differential unit measures 175mm across its mounting faces.
The choice of ratios are as follows:

Standard differential
RATIO FINIS NO. PART NUMBER
3.97 6146561 8500 4006 DC 1.6/1.8 CVH. 2.0 DOHC
3.62 6146560 8500 4006 BC 1.6/1.8 CVH. 2.0 DOHC, 4x4
3.38 1630004 8500 4006 AC 1.8 CVH. 2.0 OHC. 2.3
Diesel
3.36 6124451 8500 4006 FB 2.9
3.14 6152100 87BO 4006 OB 2.0 OHC & DOHC, 2.3 Diesel

Limited slip differential
3.92 6171465 8600 4006 AAA 1.6/1.8 CVH. 2.0 DOHC
3.62 1648393 V87BB 4006 BAA 1.6/1.8 CVH. 2.0 DOHC 4x4
3.38 1648394 V87BO 4006 CAA 1.8 CVH. 2.0 OHC 2.3 D
3.36 6142222 8500 4006 AAA 2.9



Two different types of CV joints were used.

Tripod and Lobro

Alan

Edited by Alan Whitaker on Friday 20th May 20:58

magpies

5,129 posts

182 months

Friday 20th May 2011
quotequote all
I'm sure the P100 had a 4.6 diff and the 2.0ltr Scorpio a 4.27 which is the one I have (now with LSD)