Here's what I've learnt so far...

http://www.carbuilders.info/wiki/index.php/Sierra_Diffs

Please feel free to add to it.

is that your own site?

yes

i think you have the diff ratios wrong, sure its a 3.62 and 3.38
nice info though

You may be right. I'll dig out the info and change it tomorrow unless someone beats me to it.

The spelling mistakes are scary!

Anyway, can you say at the top exactly what is 7" to make it easier for all who read?

Think it's the width of the top brackets.

Pat...

quote:

---

Originally posted by Avoneer
The spelling mistakes are scary!

Anyway, can you say at the top exactly what is 7" to make it easier for all who read?

Think it's the width of the top brackets.

Pat... A couple of minor ones ????????????
Are you having a Giraffe ............!!!!!

[Edited on 15/6/07 by NigeEss]

---

snapper - 16/6/07 at 06:33 AM

Seek and ye shall find, We are not the only people that covet the Sierra diff.
Sierra Owners club diff info
its been on here before but can't hurt to give another airing.

For discusion however as i understand 7" and 7"1/2 is the size of the crown wheel, 7" has a top bolt that goes all the way through the top mount and 7 1/2 has two bolts one either side.

The only true way of knowing what ratio you have is the diff tag or counting the teeth on the crown wheel and pinion.

I found that i had a 3.38 in a 2.0l sierra manual and like a fool sold it before i new what i had. Now following a 2.3 diesel around Braintree.

It is possible to have a LSD rebuilt with the crown wheel and pinion of your choice.

[Edited on 16/6/07 by snapper]

---

triumphdave - 16/6/07 at 01:33 PM

I have a Cortina live axle in mine does anybody know if you can swap the internals over with sierra ones I seem to have a lot of play in mine

---

andyharding - 16/6/07 at 04:33 PM

Doubt it very much

---

snapper - 17/6/07 at 06:59 AM

the diff casings are totaly different (sic) and cannot be swapped, may be time for a rebuild or keeping looking out for a scrapyard replacement, a bit rare though.

---

scootz - 17/6/07 at 07:17 PM

I'm a bit confused. I'm sure the prop input flange on the non-lsd Sierra diff that I removed from my car was centrally positioned. I just bought a new lsd, but the propshaft input flange is most definately offset. I'm now concerned about the mounts...

Am I going mad?

---

andyharding - 17/6/07 at 07:19 PM

Yes, all 7" casing are the same.

---

scootz - 17/6/07 at 07:23 PM

B*gger... better call the men in white coats!

So, all prop input flanges are 'offset' on 7" diffs?

---

andyharding - 17/6/07 at 07:25 PM

Relative to the output flanges not the mountings though.

---

andyharding - 17/6/07 at 07:43 PM

I've posted an image here from above:-

http://www.carbuilders.info/wiki/index.php/Sierra_Diffs

---

scootz - 17/6/07 at 08:21 PM

Ta... just need to work out how I'm going to convert my 'push-ins' to lobro now!

---

andyharding - 17/6/07 at 09:00 PM

If you mean so you can use drums / push in shafts with an LSD then I'm in the process of doing this so I'll write another guide when I'm done.

---

scootz - 17/6/07 at 09:38 PM

No. I have discs and my present half shafts have a splined diff input. I understand that the Sierra LSD diff cannot accomodate a splined half shaft. I'm sure I read somewhere that I may have to adapt the half shafts to lobro...

I could be wrong though... I frequently am!

---

JoelP - 17/6/07 at 09:46 PM

rear disc brakes dont come 'naturally' with the push-in drive shafts. Yours might be a drum to disc conversion or mayhaps you already have hybrid shafts. Easy photo diagnostic!

---