ARTICLES

Tips for purchasing 30 through 60 series John Deere tractors
By Chad Meyer - York, Nebraska

If you are a fulltime farmer/ranch or live on a large acreage, the odds are pretty good that you've purchased a used tractor at some point. Perhaps you went into the deal fully aware of all the items you needed to check on the tractor before agreeing to purchase it, but if you're like many buyers, you probably still had some doubts about just what kind of condition it was actually in. So I decided to write an article detailing what to look for when purchasing an older John Deere row crop tractor, although most of these items would easily apply to other brands. I'll list the easy checks to make component by component and throw in the occasional "more technical" test that can be done before purchase.

First, I would like to state that I'm a professional JD service technician with nine years of experience working on several brands of tractors, combines, trucks, heavy equipment and various other machines. Most of what I will be mentioning will be items covered under a standard JD row crop tractor inspection and may be familiar to those of you who have had a tractor inspected or serviced at a JD dealer.

Since the engine is the most important component of any tractor, I'll begin there. The most common problems will be fluid leaks and engine wear. Carefully look over the entire engine for these leaks and don't be afraid to get down and look underneath. Oil leakage at the clutch housing area of a power shift 30 or 40 series tractor will indicate a leaking rear main seal or transmission input seal, which will require the tractor to be split for repair. The clutch housing on the Syncro-Range, quad-Range and 50/55/60 series tractors will have transmission oil in it, so look at the hydraulic oil for signs of a possible rear main seal leak. If the transmission oil is black and smells like engine oil, you're looking at a leaking rear main seal leak and a split to repair it. The 50/55/60 series tractors use an aluminum rear seal retainer that liked to allow the rear seal to walk in on the crank seal surface, which causes rapid engine oil loss into the transmission and potential engine damage. This problem usually occurs around 4,000 to 5,000 hours, so you might ask if that issue has been encountered or addressed. Keep a close eye on the engine oil pressure gauge in those models and shut the engine off immediately if the stop light comes on. Things get expensive in a hurry if you continue to run the engine-usually a connecting rod bearing and crank journal are the first victims. This problem has been addressed with a new rear main seal, so if you do have to replace the seal, it's likely that it will never need to be done again.

Other common areas for fluuid leaks on Deere engines are at the valve cover gasket, water pump weep hole, the small aluminum cover over the lift pump boss on 30 series tractors and at the right-hand rear corner of the head gasket where oil commonly leaks on the higher horsepower tractors. That sealing problem has been addressed by Deere, with improved head gaskets, hardware and a new torque sequence. Tractors repaired with those updates generally remain leak-free, unless they're worked extremely hard or abused. Other than those areas, most Deeres stay fairly dry as far as leaks are concerned and it's not uncommon to find a well maintained tractor that has no fluid leaks at all.

Carefully inspect the belts, hoses and pulleys for damage and wear. Look at the crankshaft damper. Deere recommends replacing the crankshaft damper at 4,500 hours; the new dampers are usually black, so if the tractor has in excess of 4,500 hours and still has a green damper, it will need to be replaced. This is done to prevent the crankshaft from being damaged by engine vibration. also check the hydraulic pump coupler for excessive play at this time.

Check the oil and coolant levels before startup. If they're not full, it can be a good indication that the tractor hasn't had the best maintenance or that some mechanical problem is causing the engine to "use" these fluids. Next, start the engine. Pay close attention as the engine starts. Does it fire right up or require some cranking? Does it smoke excessively at any engine speed? Excessive smoke is a relative term because most of the Deere faithful are aware that the older tractors tend to smoke some at startup, idle and when cold, particularly the 30 and 40 series tractors. Fuel system and engine wear can lead to hard starting, as can low battery voltage. If the engine cranks well but doesn't start readily, there's a chance that you'll be looking at some expensive repairs to fix the problem, be it an engine overhaul or fuel system repair. Compression checks and/or testing the nozzles will usually tell the tale in that situation. It's also not uncommon for there to be a leaking check valve or weak transfer pump, which can cause the fuel system to lose its prime. Those are both relatively easy and inexpensive repairs to make.

If possible, have the seller run the tractor on the dyno. Check the engine vent tube for excessive blow-by or dripping oil while the engine is working hard. Some vapor and an occasional drop of oil are normal, but if either seem excessive, it's probably overhaul time. Check to make sure it produces its rated horsepower or slightly more, as Deere tractors tend to produce around 10 percent more than their rated horsepower. Be wary of tractors that are cranked up excessively, regardless of how proud the sell is of his "hot rod." Turned-up and overfueled tractors are large shop bills waiting to happen. Beyond those items, check the normal engine functions that you would look at on a used car, such as idle speeds, strange noises, throttle response and dso forth. Watch the gauges and make sure that all stay in the normal operating ranges. It's pretty hard to warm up a tractor good without working it, so once again, the dyno or a demo period could tell the tale. It's also a good idea to check the exterior of the radiator and oil cooler/evaporator for plugging as that could once again point toward poor maintenance and possible problems down the road. Overall, most engine problems will be readily apparent, either through fluid leakage, unusual noises or the aforementioned starting problems and symptoms during engine operation.

Moving back from the engine, our next stop is the transmission, rear axle and final drives. A lot of problems in these areas will not be readily apparent so you have to put some faith in tests that are easy to perform and hope for the best. First, check the level and condition of the transmission/hydraulic oil. If the level is excessively low or the oil is discolored, "sparkly" or smells burnt, I would recommend moving on to a different prospect as major problems may be lurking right around the corner. Look for excessively leakage, such as puddles on the ground. It's not at all uncommon to see a small amount of oily dirt gather at various gaskets, lines, seals and so forth, so don't be afraid of those minor leaks-you'll find those on brand new tractors after a few hours of operation.

Most of the easy checks will be made during operation, so climb in and fire it up. Drive the tractor and listen for unusual noises and try to feel any vibrations. Some gear noise and vibration is normal, so you'll have to be the judge of what should or shouldn't be happening. Make sure the transmission goes into gear easily and stays in gear under load. You won't hurt anything by applying the brakes to make sure the trnasmission doesn't slip or jump out of gear. A somewhat common problem on the 30 and 40 series power shift tractors is a slipping torsional damper. The damper is mounted on the flywheel and consists of a clutch disk, pressure plate and springs. The damper is always engaged and can't be released, but just like a regular clutch, it will slip if it gets oil on it or if the springs become weak with age and stress. Many slippage problems that appear to be internal transmission problems can be traced to a slipping damper, which is a relatively cheap and easy fix compared to major tranmission work. The Perma-Clutch used in the Syncro-Range and Quad-Range tractors is probably the most indestructible component ever installed in ANY farm tractor and they usually don't give any problems as long as the transmission operating and lubrication pressure are what they should be on each type of transmission.

That brings up another good point. If at all possible, verify that those two pressures are witin specs. Low operating pressure can lead to internal slippage and wear and low lubrication pressure can indicate internal wear that is allowing too much oil to escape past the various parts-much like engine oil pressure can help determine the condition of main and rod bearings. It's not uncommon for the operating pressure to be low, as it can decrease as the spring that maintains it weakens. It's very simple to shim the adjusting spring up to bring it back into specs. Low lubrication pressure isn't as easy to remedy as it generally indicates excessive amounts of lube oil getting past worn parts. When driving a power shift tractor, check that the shifts occur quickly and smoothly. A long, delayed shift can indicate internal leakage or damage to the transmission elements. also look for excessively jerky shifts. Most people who have spent much time in a Deere eight speed power shift tractor are aware that they can shift pretty rough in some instances, but be wary of a tranmission that wants to throw you out of the cab during shifts. Some other items to check are the condition of the shift linkage and proper function of the transmission pressure and filter restriction lights.

When checking the differential and final drives, listen for excessive gear or bearing noise. also listen for clunking noises that could point toward excessive backlash in the ring and pinion, damaged reduction gears or damage to the final drive gearing. If possible, jack up the rear of the tractor one side at a time and listen and feel (by placing your hand on the axle itself) for excessive final drive bearing clearance. If there is some play, it's generally not a big deal to fix, but it will require removing the final drives and likely the installation of new bearings and seals. It's a good idea to periodically check for play at the final drives, as excessive wear can lead to axle damage and possible axle breakage, which can cause extensive damage to the tractor cab and fenders. Occasional checks of the final drives are cheap insurance.

Another major check to make is the function of the differential lock. Drive the tractor in a straight line, depress the differential lock pedal and attempt to turn in one direction and then the other. The tractor should tend to keep going in a straight line, although it will turn to some small degree. The differential lock should immediately release when either or both of the brake pedals are applied. If the differential lock is not functioning or is making noise or slipping, find another prespect since it's a long way into the differential. At the minimum (providing there is oil pressure to the differential lock itself), servicing it will require removal of both final drives and the rockshaft housing. At the worst, it may require removal of the cab, transmission brake pack, reduction gears and differential pinion, depending on the damage found inside. It's not a pretty picture.

It's also a good idea to check the condition of the hubs and rims at this time. If the tractor is equipped with wheel weights, make sure the hardware securing them is in good condition and tight. It's also not a bad idea to check the wheel hardware and re-torque after a few hours of operation, particularly if the wheels were moved to match your row spacing.

If the engine and power train check out okay, you're well over halfway home as those are the major items to look out for. There can be other problems to make you shy away, but they aren't nearly as expensive to repair in terms of time and money compared to the engine, transmission, differential and final drives.

Next, you'll want to check the condition of the hydraulic system. Look for leaks (some oil residue or dripping at the remote couplers is common). Use a jumper hose in the remotes or connect the tractor to some piece of equipment and make sure that each of the SCVs (Selective Control Valves) will detent in the extend and retract positions and that they will go into the float position. If they won't, the problem could be as simple as linkage adjustment or the SCVs could need to be rebuilt. Listen for noise in the hydraulic system. Some pump chattering at startup is not uncommon, but it should quickly go away. It's also a good idea to have a main hydraulic pump quick-check performed, which will verify that the pump is producing its rated flow at a specified speed and pressure-generally 1500 psi at 1000 engine RPM. Standby pressure should also be checked and it should be in the 2300-2500 psi range. Adjusting the standby pressure is fairly simple, so if the pump flow is up to specifications, the hydraulic pump is probably fine.

Operate the three-point hitch throughout its total range of motion and make sure it performs correctly throughout the range of load and depth positions. Like the SCVs, if the hitch doesn't act right, it could be a simple adjustment problem or it could be a problem in the hitch valve or rockshaft cylinder that will require more in-depth repair. Generally, if the hitch goes up and down properly and doesn't settle quickly, you'll probably be okay.

It's not a bad idea to put the hitch at about the halfway point of travel and then put a large pry-bar between the underside of the lift arms and the top of the final drive housings. Pry up and feel for excessive movement. If there is much movement at all, the rockshaft bushings are worn and will require replacement. This is common on tractors used with heavy mounted equipment and will require the rockshaft housing to be removed for repair.
Now, providing everything has gone well so far, you're in the home stretch and probably hav a pretty decent prospect on your hands. The final major item to check is the condition of the front axle, whether it be a two wheel drive tractor or one equipped with MFWD.

The first thing to look for is excessive play in the steering linkage. Have someone steer the tractor while you watch the steering arm and tie rod ends for play. Some play in the tie rod ends isn't a big deal, but if the steering arm appears to be loose on the steering motor spindle, the front axle will need to be removed to repair it. If the wear and play is severe, the steering motor spindle and steering arm will likely need to be replaced. The steering spindle is only available as a matched set with the steering piston, so it's not a cheap fix. It's not uncommon for the person doing the repair to just replace the spindle since replacing the steering piston requires removing the frame rail (or rails) and a fair amount of work is involved in doing that.

If the tractor is equipped with MFWD, perform this simple test to verify that it is working properly. Engage the MFWD and drive the tractor at about 4 or 5 miles per hour on a hard surface such as concrete. Turn the wheel fully to the left or right, engage the clutch and allow the tractor to coast to a stop. Then, turn the MFWD switch off and note what happens. The front of the tractor should jerk sideways somewhat, which occurs when the MFWD clutch releases and allows the tension in the front differential and drive-line to be released. If this doesn't happen, the problem could be a simple electrical fault or it could be damage in the differential or MFWD clutch itself not allowing the clutch to engage OR disengage. The MFWD clutch is spring applied and hydraulically released and generally the problem is in the electrical circuit that controls the flow of oil to the clutch pack.
If that checks out, my next step would be to jack the front of the tractor up and check the condition of the pivot pins and bushings, spindle bearings and wheel bearings. Jack under the front frame rather than the front axle so that you'll be lifting the tractor "off" the axle since that will show you any movement in the pivot pin area. The pins and bushings fit pretty snug when new, but a small amount of play is normal in a tractor with some hours on it since they were last replaced. If the play is 1/8th of an inch or more, it's possible that the bushings are completely gone, which allows the pins to wear against the bushing bores, possibly to the extent that they will no longer hold a bushing. This will require some major work to repair, so be wary of a tractor in that condition.

In the case of the spindle bushings or bearings, some play is again normal so just make sure they're not terribly loose. It can be hard to check the spindle bearings on an MFWD tractor due to the size and weight of the wheels and tires so use a large pry-bar to move them and check for wear.
There's really no way to check the hub bearings on an MFWD tractor and the bearings require no maintenance on an MFWD anyway, but on a two wheel drive, the wheel bearings should be at least fairly tight. Rotate the wheel and feel for roughness in the bearings. Some play or roughness in the bearings isn't really too big of a deal as they aren't very expensive to repack or replace. Popping off the hub cap andinspecting the condition of the grease can give you some idea of when they were last serviced. Deere and others make bearing kits for most of the popular tractors, with everything in one box, and installation and adjustment is fairly simple so don't be scared away by a tractor with slightly loose wheel bearings.
Well, if you've gotten this far and everything looks good, you've probably found a decent machine to add to your fleet. The last items are usually relatively minor, but are still important to the overall condition of the tractor. Pretty much everything at this point relates to the cab. Check the function of the heater and air conditioner, if equipped. The heater is fairly simple-if the cooling system has coolant in it, the heater core is clean and the blower fans work, you should have heat. The air conditioner is a little more complex. It can take a fairly substantial investment to bring a nonfunctioning air conditioner back up to par. The older examples of these tractors have a nasty habit of rusting out the steel a/c lines that are located under the cab and alongside the left-hand rear cab post. They can be a bit of a bear to change, but aren't terribly expensive. Items like the compressor, condenser and evaporator/heater core ARE expensive to change, so if there are major issues there, or you have reason to expect problems, you might be money ahead to move to a different prospect.

Other things to look for around the operator's station are the condition and operation of the seat and seat suspension, operation of the windshield wipers, lights, gauges and so forth. Lighting problems can be as simple as bulb replacement or as complicated as replacing whole harnesseses, so look carefully. Make sure that all gauges function and come up into operating ranges while you're running the tractor. It's a good idea to make sure that all warning lights come on when the key switch is first turned to the run position. This is the lamp check and will indicate whether or not the various warning circuits are working properly. It's not unheard of for a shady seller to simply pull a warning light bulb out, rather than finding and curing the reason it's coming on. If one of the lamps doesn't light during the lamp check, find out why before purchasing.
After all that, just check the general condition of other various items, such as cab interior, paint, glass and so forth. It's not too terribly hard to put a ratty or worn cab interior back into shape. All of the various upholstery pieces are available at your JD dealer and it just requires a little patience and elbow grease to put a cab into like-new condition. I don't particularly like doing cab interiors and haven't done many, but even I can do a reasonably good job if I take my time. I'm sure you can, as well.

Well, that just about sums it up. Any tractor that passes all of these tests with anywhere close to flying colors is probably a pretty good machine, regardless of hours. It's not uncommon to find a well maintained, high hour tractor that is a better buy than a lower hour but poorly maintained one. If you're new to this or aren't comopletely sure of what to look for even after reading this, try to recruit a knowledgeable impartial observer to go along with you. Usually two sets of eyes are better than one and your helper might catch something that you missed and vice versa. All that said, you should be all set to go out and find your new baby. Best of luck with your "new" tractor.

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