This page brings together more than 700 parts for the John Deere 6620 from the 6020/6020SE series, such as trailer couplings, lighting and electrics.
By now most John Deere 6620 tractors have plenty of hours on the clock, and the jobs that come up reflect that: a sticking thermostat, a tired belt, a hose that has gone soft, a seal that weeps. This page lists more than 700 replacement parts that fit the 6620, from GRANIT, HELLA, ROCKINGER, Wabco and Sauermann.
For the cooling system there are thermostats with the matching regulator housing gasket, radiator hoses and hose sold by the metre. The belt drive is covered by multi-rib belts and complete belt kits including a pulley. Alternators, an engine oil pressure sensor, O-rings for the oil pump and other seals are here too.
Fit a new gasket on the thermostat housing every time and never reuse the old one. Clean both mating faces thoroughly, since a scrap of old gasket left behind is enough to cause a slow drip. While the system is open, squeeze each radiator hose. If one feels hard and cracked, or soft and swollen, replace it in the same job. Bleed the cooling system after refilling and check the level again once the engine has cooled down.
At the rear there are automatic drawbars, drawbar frames and forced steering parts with a ball at both ends for steered trailers. Work lamps and external clutch plates complete the selection.
A multi-rib belt that squeals on a cold start is either glazed or no longer properly tensioned. When you change it, spin the tensioner by hand, and if it feels rough, replace it at the same time. Whether the tractor has air conditioning or an air compressor decides which belt kit fits, so count the pulleys first.
The type plate on your 6620 gives the model and serial number. Engine parts such as the thermostat housing or alternator often carry a reference number as well, and that is what you compare with the product details. For O-rings and hoses, measuring the old part gives extra certainty.
The 6620 sits in the John Deere 6020 series. Each model in that range has a page of its own, handy if a second tractor on the farm needs parts: John Deere 6120, John Deere 6220, John Deere 6320, John Deere 6420, John Deere 6520 and John Deere 6820. Other Deere models on the farm can be found via John Deere parts.