[Rd1978]

2000 ultramatic kodiak 400 the front driveshaft and coupler ( engine side) stripped so I ordered new ones for the life of me I can't figure out how to get the engine side Coupler out there doesn't seem to be any bolts holding it in the coupler, its hollow inside to the output shaft I sprayed pb blaster in there but haven't done much since.. doesn't make sense and I can't find any info online or in any repair manuals ( thanks in advance!)

 

[Hosk1956]

Parts diagram from Partzilla.com, remove the seal part # 30 and you will need a special tool to undo the special internal nut, part #29.
The tool is like a tube spanner with 4 prongs on it, I had no success buying one here in Australia so I made mine from some boiler tube, worked a treat, I can supply pictures and measurements if you need them.

Wayne from Oz

 

[reogem]

I've have not worked on a 400.
However, looking at the part diagrams and the service manual the engine side coupling is not fastened to the shaft it simply floats on the middle gear output shaft. The drive shaft slides inside the couplings. The mounted distance between the engine and the front diff keeps the drive shaft in the right position.

The special nut part 29 retains the middle gear shaft and bearing in the crankcase. The coupling floats on that shaft outside of that nut.

 

[Hosk1956]

I've have not worked on a 400.
However, looking at the part diagrams and the service manual the engine side coupling is not fastened to the shaft it simply floats on the middle gear output shaft. The drive shaft slides inside the couplings. The mounted distance between the engine and the front diff keeps the drive shaft in the right position.

The special nut part 29 retains the middle gear shaft and bearing in the crankcase. The coupling floats on that shaft outside of that nut.

My bad, I read that wrong, you are correct reogem, that coupling just floats and should only slide onto the engine output shaft, all held in place by the engine and front diff mounted solid, the front shaft pushes up against a spring at the diff end to provide some backlash pressure.
I had to replace the front shaft, the coupling and the engine output shaft on mine, all the splines were stripped.

Wayne from Oz.

 

[reogem]

Hey...Wayne from Oz....Yamaha has a mixed up confusing method of laying out those diagrams. Actually their service manuals provides little help to some questions.