The John Deere 8320 belongs to the 8020 series. Find more than 200 matching parts here, including lighting, trailer couplings and electrics for this model.
On a big tractor like the John Deere 8320, the parts that keep a working day comfortable and safe tend to come first: the seat, the lights and the trailer connections. This page holds more than 200 replacement parts for the 8320, made by GRANIT and by brands such as ROCKINGER, GRAMMER, Walterscheid and HELLA.
The 8320 is part of the John Deere 8020 series, which also has versions marked with a T after the model number. Start at the type plate to confirm exactly which designation your machine carries. Then look for the number on the old part: a sticker under the cushion on seats, the alternator's own plate on alternators, the hex on most sensors.
The page lists air suspension tractor seats and seats from the GRAMMER Maximo line. When an air seat slowly sinks, run the compressor under the cushion and listen for leaks before replacing anything. A split air bag or a loose hose is a common cause and a far smaller job than a complete seat. Check the power feed to the seat as well, since the compressor will not run without it. For lighting there are LED work lamps, including wide beam floodlights.
Whenever the alternator is replaced, spin the belt tensioner pulley by hand. A tensioner with a rough bearing or a weak spring lets the belt slip, and the new alternator ends up blamed for a charging fault it never caused. If the pulley rumbles or catches, change it at the same time. The gasket on the turbocharger oil return line is another small part worth watching, since a leak there leaves an oily film on the block below the turbo.
Several other models in the 8020 series have a page of their own, which helps when you run more than one of these tractors:
Parts for every other model of the brand can be found under John Deere parts, including smaller and older tractors that may share the yard with your 8320.