I'm afraid we do not have any kind of a repair manual for your transmission. The only available information on it is the parts images. For what it's worth, I did check a number of random parts and found that quite a few parts for the transmission are no longer in production.
With the age of the machine being what it is, you may have a very hard time finding much information on it. I recommend you check with a local shop to see if anyone there may have a repair manual for it.
If you want to look at the parts images, you can go
and use 917.633A29 as the model number. If you need parts for the tractor you would obviously use the tractor model number.
I wish I could be of more help to you, but I'm afraid the age of the tractor means we have limited information on it anymore.
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