okay i have a m2b4 w/a broken mainshaft 5th gear and broken 5th gear on the counter shaft.
countershaft has the 4/5 sleeve stuck onto it also.
i have an extra great condition m2y4 transmission. i have opened both up and tried the swap.
so far.....
m2b4 jdm housing
jdm lsd
m2y4 mainshaft in place
m2y4 countershaft in place
w/ gear housing cover off everything goes in gear and spins
i attempt to place gear housing cover on and have a hard time. yes the break stopper keeps falling out of position and the bearing on the mainshaft keeps getting stuck in the housing.
i finally was able to bold it down ...i could shift 1/2 fork but not 3/4 fork or 5th fork.
i noticed that the mainshafts are obviously different do to a/ part numbers and b/ 1/2 gears.
now.... has anybody done this before??? if so.....
do i change the final drive on the lsd to the m2y4...?? alignment issue??? but it does spin in gears and neutral w/ cover off.
any input or help appreciated.

 

okay well success.
m2b4 casing
m2b4 lsd
m2y4 gear set and shafts
removed one washer from mainshaft where it slides through bell housing.
spring washer still in place just removed the one washer after it. gears line up just fine.
everything spins and engages perfectly. now to test on the road.

 

I always thought the non jdm lsd gears wont work in a jdm lsd casing... wider or longer in the diff area etc....

 

for the most part the gears are almost identical in length.... the only differences i have noticed is the the mainshaft is different between 4th and 5th gens. I do want to reassemble the jdm gear set and put it back in the original housing.... i have to get new 5th gear /5th gear syncro set/ mainshaft/ 4th/5th sleeve and I might as well buy new bearings. unfortunately the 4th/5th gear sleeve is jammed onto the mainshaft. I tried to press it out ... no good. i know the gears on the jdm 1st gear is the shortest out of the m2xx transmissions... so that sucks.

 

So the shafts are longer in the lsd tranny? The case is bigger to hold the larger diff, but I didn't know if the shafts were also longer.