Diff ID help with numbers

[67411sss]

I have a couple of diffs down at the storage pit, went a had a look at them today to get some numbers off them.

213, t25, 21160, 2?311 is on one

208 and what looks like 113 on the other.

Any idea what they are without taking the plate off. Thanks Rory.

[datzenmike]

This is IRS?It wouldn't have the ratio on the case anyway. You would have to take the cover off and rotate the crown around and find the numbers stamped on the outer edge, Divide the small into the larger. 35/9= 3.889

[thisismatt]

External case numbers are mostly useless as far as I've ever seen. I can think of one instance where it may be useful, and that's on the R180 diffs where the newer housings have a large 'K' on top, which doesn't really give you much info other than to let you identify it as being newer than the older ones and likely having 115mm ring gear instead of the older 110mm gear, which changed mid-year in 1976. But then again, even the subi R180's have the K and unless you have custom axle stubs this doesn't help you.

[67411sss]

Yes IRS, guess i'll take the plate off, snatch some pics, count the teeth and get back to you.

[datzenmike]

I doubt you'll easily see the pinion anyway. Just look on the outer surface of the crown (or ring) gear. Spin it around and look for numbers stamped into it. Those will tell you the ratio.

 

Will look similar to this:

 

 

37 / 8 = 4.625.

.

[67411sss]

Ok, so here's what i got

Diff 208 has 37 teeth and # 037 11b 0 08057

Diff 213 has 39 teeth and #39 1c acop2 (or maybe it's a 10 instead of 1c, hard to tell with the stamping)

And i can turn both shafts the same way on both diffs

[datzenmike]

Ok, so here's what i got

Diff 208 has 37 teeth and # 037 11b 0 08057

Diff 213 has 39 teeth and #39 1c acop2 (or maybe it's a 10 instead of 1c, hard to tell with the stamping)

And i can turn both shafts the same way on both diffs

 

37/11 would be a 3.364

39/10 would be a 3.90

 

It's unlikely they are LSD. Sometimes they are stiff enough that they will both turn together. Hold one side still and if you can turn the pinion then they are not.

[67411sss]

Once again, thanks Mike. That 3.364 seems like a tall gearing? From looking online it seems like it's from an early Z.