This forum is a bit different than most other forums out there on the internet.
We pride ourselves in having the largest library of original manuals that were written by the Colt, Case and Ingersoll factory that can be found anywhere. I fully realize that new members need some time to acclimatize themselves to forums because of the differences in how each forum is structured. While we do encourage our members to ask questions and also offer opinions to questions asked by others, we also expect members to spend time exploring the Service Manuals, Parts Manuals, Operator Manuals and the FAQ documents as they pertain to their own tractor or tractors. By reading such material on your own, you often get the very best answers to questions you have have now or even later.
As an example, we have a 108 Op Manual and Parts Manual available for you to look at and even download to your hard drive or printer. In the Service Manual section, there is information about the trans-axle your 108 uses specifically.
In the FAQ's section, there is the chart that gator provided the link to so that you can confirm the model year of your 108.
You will find more information on this site right at your fingertips than you will find at three other Case sites combined.
We are happy to have you here as a member and look forward to helping you with your 108.
I think that you may find these two threads of interest to you.