3.92 was installed in the w115 220D. Some had 4.07 as well.

Your 86 and up W126 has a different diff mounting than the earlier w126, which interchanged with the W123 and W115/W114 pumpkins.

Also, the V-8 cars had a larger diff, 1.3L vs 1.0L capacity.

Jim

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14 E250 BlueTEC black. 45k miles
95 E320 Cabriolet Emerald green 66k miles
94 E320 Cabriolet Emerald green 152k miles
85 300TD 4 spd man, euro bumpers and lights, 15" Pentas dark blue 274k miles