M103 and M104 gearbox
Do the M103 engines and M104 engines (G300s and early G320s) share the same gearbox?
Regreatably I do no thave the resources to check this out but it is an easy exercise; compare gearbox part numbers for the both, I am going to guess to say that they are the same. However, don't hold me to it.
If you have a chassis number of both vehicles ask the dealer to see if the part numbers are the same, given the chassis number they will no doubt check ths out for you, it is easy enough. But if you ask them to research this for you they are usually unhelpful.
5 speed getrag box manual for the 300ge and a 4 speed auto too; not sure they are the same for the 320, which didn't come in RHD form to the UK. Both engines featured in the w124 cars and some of the autobooxes had a 5 speed unit with the 104 engines, it doesn't have a great reputation though, most commentators say dont bother stick with the 4 speed auto box
not a mechanic, probably same gearbox with different gearing, maybe somebody more technical can shed some light on this:
G320 4speed auto: W4A028 (722.372);
G300 4 speed auto: W4A028 (722.397).