664J Loader with a 6068 Hard to Start and then Dies!

What could be happening is your charge pump is losing prime. The way you test this if you don't have a laptop that talks to John Deere Equipment have someone crack one of the fuel lines leaving the injection pump. Have them watch it to see when it stops pumping. Next crack the line going into the injection pump if it stops pumping then it is your charge pump. If it didn't stop pumping then it is your Injection pump. 

Brand new Gator xuv 550 S4 makes grinding noises when using 4 wheel drive!

First you need to verify that it is only in 4 wheel drive that it makes popping or grinding noises. Check to see if there is the appropriate amount of oil in the transmission. After you've confirmed that there is the proper amount of oil and the noise only occurs when you are in 4 wheel drive, remove the front driveline where it comes out of the transfer case. With the Gator on jack stands so that none of the wheels touch the ground run it to see if the noises have stopped. If so then it is coming from your front end. If not then it is coming from your transfer case. Remove the transfer case to verify as you may have gear teeth in the transfer case missing or broken.

International Hydro-84 after servicing loses all hydraulics!

When servicing any tractor this something to be aware of is air locking. This happens when the oil in the pump gets drained while changing the filters. The pump will then try to push the air through the system with out any help and most of the time that works but occasionally when the pump can't get rid of the air you need to crack a line to let the air out. With the International Hydro-84 you get under the hood where the steering lines are at their highest point. Crack the line and have someone hold the steering wheel in the direction that is forcing the air out of the line. When oil starts to come out consistently tighten it back up and there you go, you now have your hydraulics back.

Tractor Pulls!!!!

Here's a video of some amazing power producing machines showing what they got. http://www.youtube.com/watch?v=u6a1NdnETDw

4105/3032 E Won't Drive Forward or Backward

This particular model has a hydro-static drive transmission. The bracket that connects the linkage to the transmission is prone to breaking. Crawl underneath the tractor and follow the linkage to where it enters the transmission housing. If everything is fine then the problem is probably the hydro-static circuit but this failure is a usually a gradual failure. If the failure is an instantaneous failure then it is more then likely not the circuit.