Shifter Shaft Question

I have an 87 KDX 200 that had the shifter shaft broken off and the shifter subsequently welded on to the end of it. It leaked oil out of the seal so I thought that I would change the seal, shifter and shifter shaft all at once. I have been having nothing but problems with shifting ever since I did it.

The shifter shaft seems to have a lot of side to side play in it, so much so that it actually comes out of the position that it needs to be in inorder to hit the shift drum

Is the return spring on the shifter shaft supposed to hold it from going from side to side? I actually used a piece of plastic between the shifter and the case to stop it from going side to side and I know this isn't right.

I have bought a new change lever spring and bolt and am going to order a new return spring.

Is the return spring what is supposed to hold the shifter shaft from moving? Or is it supposed to push up against the case or is there supposed to be something that sits over the cross in the case that pushes against the shifter shaft?

I have a manual and don't see anything that looks like it should be holding it other than that spring.

Any help would be great

Thanks for the replies. I had a good look at the case and figured out that at some point in the bikes life the side case had been welded. Unfortunately the pieces of the case where not in the right place when they were welded and the cross in the case was sunk too far in. I ended up welding on the end of the cross (building it up) then using a dremel to grind it down to the correct height. Lo and behold no more side to side in the shaft.

Thanks again for the replies