Diff Type?

[niduncan]

Does anybody know how to identify the ratio of a sierra diff from its markings?

 

My current diff is a 3.62:1, if it is original, as the donor VIN plate shows the axle to be a type "V". Donor was a 2.0l Ghia.

 

The tag on the diff reads:

 

83BG4006 LC

A 338 3J06 (Could the 338 signify a 3.38:1?)

 

Markings on the casing are:

 

83 BG

4003

AE

 

27 7 83 (Manufacture date I assume as donor was an "A" reg)

 

174791

99110

 

I want to get another diff from a scrappy but would like to know what I am buying. My current diff whines and there is some play in it. I am experiencing some clutch judder, the clutch has done less than 10000 miles, I have put in a new clutch cable and quadrant. I would like to try another diff before taking out engine and gearbox.

 

Any ideas?

[Big Jim]

try looking here! I really don't know why I bother putting this information on the site, if people can't be arsed looking! :angry:

[niduncan]

If you cant be ARSED to read the question properly then don't bother replying!

 

I had already read this but this is only any good if the diff is still on the doner.

 

I want to identify a diff that has already been removed from a car.

[Guest rizla]

calm down niduncan......wen on here i tend to do what alot of others do and scan not really read as such

 

the diff is a 3.38-1 as you thought,your lucky a few people dont have the plate on there diff then its the old fashioned way of turning the prop counting the turns compared to the wheels

[Guest docter fox]

may just be me but shouldnt you be looking for one with the same markings as the one youve got?

providing you dont want a limited slip diff of sumthing different are you not just looking for one the same as yours?

[Guest salty_monk]

If you can find one & you want better acceleration put in a 3.92 or a 3.62 as a compromise. The 3.38 was on the E (for economy) 1.6 & possibly one of the automatics.

The 3.62 is probably the most commonly found one with the 3.92 coming a close second.

Have a look as there are 2 different casings (somewhere between 86 & 89), I'm guessing that yours will be have a through top bolt at the top but the other casing has a bolt going into a blind threaded hole each side & the 2 are not interchangeable...

[niduncan]

Thanks chaps,

My current diff came off a 1983 2.0L Ghia manual, it cannot be original then Rizla as it should have been a 3.62:1 accoding to the VIN plate.

I shall look out for a 3.62 or 3.92 which will improve acceleration.

The diff does have a through top bolt, thanks Salty Monk, as I was not aware that the design had changed on latter models.

[Guest battery joe]

Would the Diff off a 2 Ltr Granada be any use? as we have one sitting outside

No idea what numbers on it are though but will have a look if required

[niduncan]

Hi,

Is a granada diff the same fitting as a sierra? Mine is an early diff with a through bolt at the top.

Salty Monk recommends a 3.92:1 to improve acceleration. The tag on my diff was unreadable due to rust so I had to take the tag off and sand it down to read the markings. It would be interesting to see what the granada one is if its not too much trouble. There are a stacks of scrap yards in Peterborough, some of which break cars so parts are available off the shelf. This was where I hoped to get one from.

 

Cheers.

[Peter Bell]

Hi Neil, the problem with a low ratio diff is that first gear becomes very 'short' great for towing heavy things but you have to change up quicker. So it may not necessarily improve acceleration times. I have a 3.77 diff and often use 2nd to pull away, first just seems a bit too low.

Peter

[Guest Robin Allison]

Granadas had two diff types fitted. They had the 7 inch fitted to the 2.0 pinto 3.62 on the manual and the 7.5 inch diff was fitted to the V6's not sure on the ratio though. The 2.0 DOHC may had had either fitted.

You can use the 7.5 inch diff on a 2b but you need to fit the rear torque tube from the Granada.

[Guest salty_monk]

Nothing wrong with first gear on the 3.92 diff.... (unless you're only letting it rev to 3k... )

I would even contemplate a 4.11 if I was getting one reconditioned... Horses for courses I guess!