I know that normally they had different bogie assys. I have seen an Austrailian M31 the had its bogies converted to M4 to handle more weight. Was the M3/M4 bogies interchangeable without major work, like unbolt one and bolt on another? I have seen M4 Shermans running with mixed bogies and one on backwards.

Did any of the maintenance sections replace some or all of the M31 boggies with M4 to increase load capablilty or simple no M3 bogies available?

How long were M3 Grants/Lees operated in Europe? Was there a shortage of M3 bogies at any point?

Hi Jim
I'm not certain of my information, but the M3 bogeys were a straight swap, as you say unbolt one then bolt on the other. I would say that there was replacement of the M3 bogeys with the later style for M4s (with return roller arm and track skid) only as supplies dictated. I have seen a photo of a M32B1 which has two out of three bogeys on one side using the upswept return roller arm common to later Shermans with the other the straight arm with 'pillow block' and as stated this was believed to be because of what was in the supply line. I'm not sure that they could be so choosy as to fit out specific TRVs with things like the weight in mind. The M31s (although eventually superseded) served until the end of the war.
I would say that M3 bogeys due to the duration of time served would have had to run out (or at least low.) The changes/improvements in the M4 would have dictated the changes in the TRVs I reckon...
Brad