With more than 500 matching parts, the John Deere 1850 is well covered here. The range includes lighting, electrics and trailer couplings, among others.
The John Deere 1850 is the kind of tractor you can still do a lot on yourself. Changing a clutch, swapping an alternator or resetting the toe-in can all happen in your own workshop. For those jobs this page holds more than 500 John Deere 1850 parts from GRANIT, HELLA, LuK, Wabco and MAHLE.
For the clutch there are single clutch pressure plates and clutch plates, among them parts from LuK. Once the tractor is split, replace the pressure plate and clutch plate together and take a good look at the release bearing and flywheel. If the flywheel shows blue heat marks or scoring, have it skimmed before the new plate goes on. A new plate against a damaged flywheel will judder and wear quickly. Check too that the plate slides freely on the input shaft splines. A smear of copper grease helps, but too much ends up on the friction lining.
Track rods and ball joints keep the front wheels pointing the right way. The track rods come in several lengths, so measure the old rod centre to centre before ordering. Bushes, including bushes for the lower link strut, and washers complete the chassis side of things.
Alternators and starter motors keep the 1850 starting and the battery charged. For cooling there are water pumps and V-belts. Then there is the small stuff every repair needs: gaskets, for instance for the lift housing, seals for the feed pump, O-rings for the master brake cylinder, sealing rings and hose sold by the metre.
A tip on the alternator V-belt. Too tight and it wears the bearings in the alternator and water pump, too slack and it slips and squeals. Press on the belt with your thumb midway between two pulleys and it should give by roughly a centimetre. Check the tension again after the first day's work, because a new belt stretches a little at first.
The type plate on the 1850 gives the model and serial number. John Deere uses its own part numbers for many components, which you will often find on the old part or in the workshop manual. With both pieces of information there is no guesswork in picking the right part.
The 1850 belongs to the John Deere 50 series. Two other models from that range have their own page with their own parts: the John Deere 1550 and the John Deere 4050. If one of them shares the shed with your 1850, you will find what is listed for that model there. Every other model from the brand is under John Deere parts.