120 g caterpiller has following serial number 82V748 would like to know which year manufacturer ?
82V production in Canada started in 1974 and ended in 1980. Your machine is probably somewhere late 1970s. Interested to know why you are asking.?
If you can describe what means prefix first two or three digits and after ? 82= means ? V = means ?
82V is what is known as the "prefix". It is a simply a model reference, in this case for a 120G grader. A prefix is unique to a particular model. 748 is the Sequence Number of the machine. In your case it was machine #748 off the production line of the 82V-prefix 120G motor grader.
1976, 82v 715-770