E30 Zone

Got told from a friend he had an e30 slipper,went to view it just now and if i hold one of the output shafts and turn the input, the other output shaft turns. This to me means its NOT an lsd. Ive took the tag and cleaned it and it says :

345 608

would this mean the ratio is 3.45:1?
What does the 608 mean?
is there a letter code to identify LSD?

345 would suggest a 3.45:1 ratio differential

If it was a limited slip differential, firstly both output shafts would turn in unison the same way and second there would be a 'S' before the 345.

Seems to me your friend's told you a porkie there

does the 608 refer to the casing?are there bigger or smaller types of casing?

It should also have a S stamped on the tag before the numbers

looks like it's not a LSD, or if it is, it'll need a serious rebuild
the best way to be totally sure is to open up the casing.
if you can see the planet gears through large holes in the centre spindle, it's an open diff.
if the centre spindle is more 'solid' and the gears (apart from the crownwheel and pinion) are hidden, it's a LSD

the lack of 'S' and the way the diff behaves seems to indicate a non-LSD.

a handy ratio for M30 conversions though so may be of use to someone

It could just possibly be a torsen type LSD, as fitted to more modern BMW's.
These behave exactly like an open diff. in the common tests, so opening it up is the only way to identify one of these. Look for numerous long thin spiral gears in the diff. cage.

hi,
i found such numbers at diff case s6640. what are they mean?
I think its LSD diff but can you help to determine diff type: disk or torsen?
thnx.

that's not a number code i recognise. could be a factory reconditioned unit as i believe these had a different numbering system.

whip the back off and have a look inside, and post up a few pics

Two sizes of diffs are fitted to E30,'small' has 6 bolts to the rear cover,and 'medium',which has 8 bolts to the rear cover.
3.45 was made in both sizes,although in the smaller case it was fitted behind the 324d engine!

daimlerman wrote:Two sizes of diffs are fitted to E30,'small' has 6 bolts to the rear cover,and 'medium',which has 8 bolts to the rear cover.
3.45 was made in both sizes,although in the smaller case it was fitted behind the 324d engine!

what type of LSD was installed on e30?
I know AWD has visco-LSD but what RWD: friction plates or torsen?

Friction. Torsen diffs only started to appear to be compatible with stability control systems.

plz help me to identify my diff type.
I've found 3 number codes on the case.

Those are just casting numbers, and no real help in identifying the diff.
There should be a metal tag under one of the bolts holding the rear cover on. If this is missing, take the rear cover off to identify if it's a slipper or not, and count the teeth on the crown wheel and pinion to determine the ratio.

Brianmoooore wrote:Those are just casting numbers, and no real help in identifying the diff.
There should be a metal tag under one of the bolts holding the rear cover on. If this is missing, take the rear cover off to identify if it's a slipper or not, and count the teeth on the crown wheel and pinion to determine the ratio.

thanks. I will try it.