Troy-bilt Horse Wheel Shim Question

I few weeks ago I posted a question regarding the drive axle on my Horse having some slop in it. If you grab the end of the shaft you can push/pull it in about 1/16 to an 1/8 inch. I pulled it apart today and the snap rings are in place, I was assuming one broke. There is one shim behind each oil seal.
According to the parts manual there are 5 different shims with varying thicknesses. The service manual claims these shims are used to protect the oil seal from the snap ring. Why then do they have have five different shims? The only thing this shim will do is determine how deep the oil seal can be pounded in, it has nothing to do with the shaft being able to move in and out. So I am still not sure why my axle has developed this slop. I can put it all back together with new seals but I am going have the same problem I do now.

On a side note, last year I had to replace the tiller shaft because I scored it replacing an oil seal. While I had it apart I reversed the bronze worm gear because it was wore. I put everything back together according to the manual with proper shims and clearances. Any chance that could have caused slop in the wheel axle?

Thanks

Look at the diagram again closely.



From first to last order of assembly.

4. Spacer
3. Shim
2. Snap ring
1. Seal

The shim cant determine the oil seals depth due to the fact that it will hit the snap ring and stop. The only way the seal will even touch the shim is to leave the snap ring out. Do that and the axle would slide until it is stopped by the wheel hubs.

Thank you for bringing to my attention that I am a complete idiot. I must have looked at that picture 10 times and my brain kept telling me the shim was on the outside of the snap ring. When I took both wheels off, each side had one shim on the outside of the snap ring and one shim on the inside of the snap ring. The shims that were in the correct location are now concave from the shaft moving back and forth. My master parts catalog shows two shims on each side, while your diagram only shows one shim on each side. Is your diagram for a newer machine possibly? My machine is serial 543950 which puts it somewhere in the 70s.

Is it still suggested to use some black permatex around the oil seal when installing a new one?

Thanks again for your help.