Heater Fan & Axle Ratio

[113gray]

Hi Group- My heater fan sounds like it's dying. Any advice? Is it as miserable/impossible to replace as the 108? (If so, FUGEDDABOUTIT!)
Also, I need the rear axle ratio & understand it's stamped on the axle. But that involves a lot of greasy/dirty/poorly lit/hard to get to territory. So if anyone could provide a more specific location it would really help. Regards & TIA. -JP- '66 230SL Euro(It.) 5 Spd ZF Manual

[n/a]

If your car is an "original" manual 5-speed should have a shorter ratio than manual 4-speed and similar to the US versions, i.e. 1:4.08 (1:3.92 on last 280SL's)
On your data card you should have code 230 (5-speed manual gearchange) and code 232 (1:4.08 diff ratio)
And YES, changing the heater fan do IS a mess!

Duro
Italy

[George Davis]

I think Duro is right about the ratio, it should be 4.08.  I found the ratio stamped on the differential housing, on a flat surface that (I think) faces to the left, low down on the front left side of the housing.

Your fan motor may just need lubrication, but it is indeed a project to get it out, at least the first time.  The second time around, it can be done in a day or two.  A lot of guys make it a winter project to gut the dash and fix everything they can all at once, including refurbishing the dash wood.  Figure 2-8 weeks!

George Davis
'69 280 SL Euro manual

[jeffc280sl]

I located the gear ratio stamp on my 1970 280SL earlier today.  It is located on the drivers side of the differential.  On the bottom of the drivers side of the differential you will notice two bolts.  Following a line of sight to the front of the car from these bolts is a part of the housing which is flat and approximately 3/8 inch tall and 2 inches long.  Clean this surface and you will see some numbers.  Mine were as follows:

20683 3,92

I don't know what the first number refers to but I believe the second number to be the rear axle gear ratio.

[113gray]

Thanks for the replys. I have found the rear end ratio & as previously mentioned, it is a 1:4.08. Re the heater fan, my best advice thus far has been: " move to a warmer climate!" -- (Joe Alexander) Regards. -JP-