|
I've always assumed it is because the gears in the M41 use needle bearings instead of the solid bronze type bushing type in the M40. However, I have heard that some M41s also used the solid style. Of the two M41s I rebuilt, they both used needles. The half dozen M40s were all solid.
Everyone has their opinion, but I've stuck with 80W/90 in M40s and 30W in the M41s and have not had gearbox issues.
Just to throw a wrench in though, I use Mobil1 10W/30 in my M46 and I don't know why!
They all are over 100K and shift well.
--
'60 544, '68 220S, '70 145S, '72 144E, '86 745T
|