Here is when, the swap was a one on one thing with the customer, Deere, & the Dealer, if you have the old style axle and are not happy with it during mowing (many, many are happly with the old style) you are going to have to sit down with your dealer and ask them to plead your case to the field Rep. for your area, if they won't, or you get a no, it's time to move up the food chain and call Deere yourself. I believe a good dealer could still get this done, or maybe get Deere to split the bill, or Deere buy the parts, and you pay the labor.
Good Luck !
Tractors starting with these serial numbers have the new 4-wheel drive front axle design:
Available: Immediately on 4200, 4300, and 4400 Compact Utility Tractors.
Note:4500, 4600, and 4700 Compact Utility Tractors are scheduled to receive the new
4-wheel drive front axle beginning with April production. A separate Marketing Infor-mation
Bulletin will be issued announcing this change for these tractors.
SyncShift Transmission Hydrostatic Transmission SyncReverser Transmission
4200 - C327042 4200 - H321092
4300 - C335308 4300 - H330878 4300 - S336487
4400 - H340948 4400 - S344286