Rear Differential oil level

[getsmart]

Hi All,

The BB tells me that the oil quantity for 230sl rear diff is 2.5 litres.

When I drained mine it only contained 1 to 1.5 litres. Yes I did lift both axles to drain the oil from them. I bought my car as an unfinished project so have never had it running though the diff appears to be in good condition (little backlash).

My questions are

1. Has anyone re-filled their diff and if so did they put 2.5 litres in?
2. Or did you just refill it until it started running out of the filling point? (shown in attached photo)

The diff at times had been stored pointing upwards so I wonder if there is a position where they will leak like out of the top of the breather hole.

Rgds, Joe

[Benz Dr.]

If you have the car raised and the axles are hanging down then you won't want to fill to the bottom of the fill hole. I stick my little finger in the fill hole and as long as I can feel fluid, it's full.

[ja17]

You have a nice picture of the location of the rear end ratio for an early car (3/75)

[getsmart]

Thanks Doc - my axle is removed so I'll take that as close to the car being raised. I'm curious though the low oil level. I'm guessing there's a level range that they operate fine at but should not be too low of over-filled. I might try about 1.5 litres and use your finger method and keep increasing from there in .5 litre increments up to 2.5.

If my finger gets stuck I'll call you for urgent assistance (mental note to keep the phone in my pocket) 

If you have the car raised and the axles are hanging down then you won't want to fill to the bottom of the fill hole. I stick my little finger in the fill hole and as long as I can feel fluid, it's full.

[getsmart]

Thanks Joe, yes its the original axle in my March 1964 230lsl 

You have a nice picture of the location of the rear end ratio for an early car (3/75)

[MarkCan]

I think that what Dan describe for you is the way of checking the diff oil level at service intervals. When you are filling it go slow and as soon the oil starts to come back out you are done. Put the plug back on and wipe it clean.

[Benz Dr.]

I think that what Dan describe for you is the way of checking the diff oil level at service intervals. When you are filling it go slow and as soon the oil starts to come back out you are done. Put the plug back on and wipe it clean.

Only if the axle tubes are perfectly level. Otherwise, use your little finger method.

[ronwall83]

What size alan key does a person need for both the drain & fill plugs?  Old thread...so here's hoping.

[dirkbalter]

What size alan key does a person need for both the drain & fill plugs?  Old thread...so here's hoping.

14mm Hex

[Bshaunessy]

14mm hex head: HINT: you will need to shorten a standard "L" shaped 14mm hex wrench as the spacing between differential and body is very tight.