differential ratios on 280sl

[n/a]

Does anyone know about a differential ratio change on the 280sl?

I was asked if my car has a lower differential ratio.  It is a 1971 early production dated 9/70.  I was stumped.  Was a change made to the 4 speed manual that would effect lower rpm's at 65 mph in 4th gear at some point during production?

This is news to me.  And I thought I knew a heck of a lot about these cars.  Frank Mallory's list of changes does not show anything, and the service manual doesn't appear to list anything.

Any help out there??

Thanks,
Don
1971 280sl 4 speed manual

[Douglas]

You're okay, Don. Your car should have the 3.92 rear. In January of 1969, the US-spec cars went from a 4.08 to the 3.92. They started at Serial #011132.

Douglas Kim
New York, NY
280 SL #016220

[ja17]

Hello Don,
The car could also be ordered with a different ratio. You can find the ratio stamped on the differential casting driver's side lower on the edge of the casting web.

Early 230SLs had the ratio stamped on the rear lower  of the differential in a semi-circular machined surface.

Joe Alexander
Blacklick, Ohio

[George Davis]

Adding to what Douglas wrote, the non-US 280 SLs started out with a 3.92 ratio (US ratio was 4.08), then at chassis no. 011132 the non-US cars went to 3.69 while the US cars went to 3.92.

With the 3.92 my car shows 70 mph (110 kph) at 4000 rpm.

George Davis
'69 280 SL Euro manual

[n/a]

Thanks for the quick responses!  This was a new one on me.  Ya learn something everyday, eh?  Particularly from such a knowledgable group as this one.

Best regards,
Don