Operating a Direct Drive Tractor - Discuss!

I purchased an old tired D7E direct drive (47A) low horse dozer around a year ago and have been teaching myself how to run it mostly pushing up 16- 20” diameter pine stumps that were cut off flush with the ground. I had never run a dozer before this one. I put together the following notes on what I found to work on my machine. Remember that I am a newbie to dozers, please correct and discuss!

Momentarily pressing (stabbing) one of the brake pedals as the clutch is disengaged when the tractor is coming to a stop seems to help shifting with both the forward /reverse selector as well as the gear selector. Neither selector should have to be forced when shifting.

Occasionally the tractor just doesn’t shift well. Keep working the clutch until it shifts. Dropping the blade sometimes helps to get the tractor to shift, perhaps it moves the tractor slightly to help with the shift.

Proper adjustment of the clutch brake seems to make a big difference in how well the tractor shifts. Replacing the clutch brake pad is one of the easiest things that I have done on my D7E and it takes less than an hour if you take the time to clean everything. Part was readily available at a reasonable cost from the local Cat dealer.

Main clutch should be in or out, don’t slip it!

Grease the outboard bearings on the final drive and check the final drives oil levels frequently.

If the tractor is to sit idling for a long time the recommended procedure is to put the transmission in neutral, put the direction selector in forward or reverse and engage the clutch. This will lock the transmission shifter and keep it from being accidentally bumped into gear.  Also set the park brake!

When removing stumps lift on the blade as you engage the stump, this helps to lift the stump out of the ground as the tractor moves forward.

Check for wasp nests in the console before operating the tractor!

Drop the blade and set the park brake before getting off of the machine, they roll surprisingly easy on even a little slope.

Get a narrow shovel and clean the dirt out of the undercarriage while the tractor is idling cooling down at the end of the day. Inspect for leaks and damage at the same time.

Hello, all points to consider - #1 READ THE OPERATORS MANUAL - be familiar with the controls and procedures before operating. Pre-operational checks are not optional - again consult the recommended checks done on each and every operational period, as in DAILY. Minimum - a walk around the machine (observe the general conditions, loose pins, connections, objects caught in tracks, etc) and ALWAYS - OIL LEVELS (hydraulic, engine crankcase) Water and Fuel. Secure items on or near the operators control station, loose items may block the action of the controls and always when not expected! NEVER leave the seat with the clutch disengaged and the machine in gear - (engaged clutch prevents the machine from being placed in gear, so engage the clutch prior to dismounting), always lower raised equipment, never work under raised equipment or loads, never allow others to be close to the work and only on the machine if there are provisions for them. Use proper 3 point mount and dismount procedures, never jump off the machine. Yes, the clutch will be slipped during operations as necessary to ease into the load (as example to tighten a cable or chain or making contact with an object), this is done along with throttle settings, again experience will teach you how to properly engage the clutch. Using the clutch brake prematurely to stop the machine and transmission will not aid in shifting gears. Clutch brake only stops the movement of the input shaft unless being powered by the movement of the machine. STOP the Machine before trying to shift gears. Hydraulic or cable operated attachments differ in operations and hazards, again know your machine! Always consider the object being pushed, if it can roll beneath the dozer blade and under the Tractor, you can cause serious damages, same with the root ball rising under the tractor as you push the stump out. NEVER push trees than can roll up and over, falling back on the tractor and you in the seat!

These are all starting points, your knowledge of the machine and operational procedures along with experience will teach you the fine points. Every machine and every job will produce challenges and operational procedures will differ job to job and often from operator to operator.

LISTEN TO THOSE "seat of the pants" feelings. Think about what you are doing and evaluate the hazards, if in doubt, proceed with extreme caution. Remember, Accidents do not happen, they are the direct result of an action or inaction. Always observe the conditions and plan your actions - how you react to unseen circumstances may well mean the difference between walking away smiling or being seriously hurt. PLAN AND PREPARE FOR THE UNEXPECTED. best wishes and enjoy your machine -- cts

You know what would help with the critique, Magneto - some video! : ) We love photos and videos

Always wear the seat belt! One gets jerked around pretty hard running over stumps and debris. I am going to try to post a recent picture of my tractor.

1963 low horse D7E (47A) direct drive.

converted by previous owner to 24VDC electric start (positive ground )

Picture is with root rake. blade with guard on top is a little over 6 feet tall.

undercarriage is a bit tired.

Magneto second try to post. When I clutch my machine if I go ahead and change gears it’s fine. If I let off the clutch for some reason it’s difficult and grinds. That’s why I enjoy my newer d5m cat with thumb controls. It’s every bit a learning curve and much fun for us. And I’ll add the older one are good exercises.

I would disagree about slipping the clutch on a dozer. Provided it is a Cat oil clutch. This from a guy that made his living fixing crawler tractors. I fixing a oil leak on a 9u D6 wet clutch. His advice was check the drive teeth in the clutch disc. He had never seen the friction surface wear out on a Cat wet clutch. Sure enough the drive teeth were very close to being gone. Got the new clutch disc, and my helper says be better back the clutch adjustment off for the new plate. After measuring the thickness, they were the same.

I am not advocating you go around slipping the clutch all the time. But very useful when bucking stumps. You cannot run into them wide open in low gear without putting stress on lots and lots of parts that cost a lot more than a clutch disc. You easy into the stump, then let it have full power as lifting with the blade. Or when going over berms, you use the clutch to drop over the top slowly, seat belt or no belt. My back has had way to much abuse to take bouncing around all day with those big bumps.

But I have run a D6 4r dry clutch enough in just ag operations YOU CANNOT SLIP that clutch at all.

Well stated Ray54, going over "checks" with direct drive tail seat machines, you better learn quickly how to use a clutch! Easy does it or you will have a real wake up call, your whole body will be speaking to you! I was taught, no matter what the load, pick up the slack and then snap the clutch in, I only recall having to adjust a clutch one time and that was on a 4R with bulldozer, pushing big trees, that is hard on the clutch. We did not have the luxury of torque converter drive with decelerator pedals, relied on clutch and steering frictions, all in timing. cts

Hi, CTS.

Rear seat orchard tractors 'launching' you when going over bumps without due care? Many people have little to no idea that the high sprocket machines can do the same thing 'coz you are so far ABOVE the balance/pivot point as opposed to being so far behind it.

Just my 0.02.