This document is an operator's manual for a Gravely Rear PTO (Power Take-Off) unit, Form No: 42163 (8-86), Part No: 42158. It provides instructions for safe operation, installation, removal, maintenance, storage, and includes an illustrated parts list and warranty information.

Function Description

The Gravely Rear PTO is an accessory designed to transfer mechanical power from a Gravely tractor to an attachment, specifically a tiller, as indicated by the safety instructions and operational procedures. It enables the tractor to power the tiller for ground cultivation tasks. The PTO unit consists of a chain box assembly, a universal drive shaft, and various gears and bearings that transmit power from the tractor's transmission PTO shaft to the tiller.

Important Technical Specifications

While specific power ratings (e.g., horsepower, torque) are not detailed in this manual, the document provides information on lubrication and component specifications:

Oil Type for Chain Box: SAE 30W-40 oil is specified for the chain box.
Grease Type: Multi-purpose grease is required for shaft bearings.
Fasteners: Various bolts and nuts are specified, including Hex bolts (1/2"x2.00, 1/2"x1.00, 3/8"x2.00, 3/8"x16-16), Lock nuts (1/2-13, 3/8-16, 1/4-20), and a Square Hd Steel Plug (1/4-20).
Bearings: The parts list includes various bearings such as Ball Bearings (1.250x2.250x.500), Bronze Bearings (1.002x1.378x1.000), Needle Bearings, and Thrust Bearings.
Seals: Oil seals (1.500x2.125x.312) are used in the chain box.
Sprockets: A 5/8 pitch 14 tooth sprocket is listed.
Chain: A roller chain is part of the assembly.

Usage Features

The manual emphasizes safe and correct operation of the Rear PTO:

Preparation: Before use, operators must read the Gravely tractor and tiller manuals, be familiar with all controls, and know how to stop the equipment quickly. The work area should be inspected and cleared of foreign objects. Loose clothing and accessories should be avoided. Bystanders and pets must be kept away. Children are not allowed to operate the equipment, and adults must be knowledgeable of safe operating practices. Eye and foot protection are mandatory.
Operation: The PTO should be in the "OFF" position when the tiller is not in use or during transport. The tiller should be disengaged and the engine stopped before clearing the unit. If a foreign object is struck, the engine must be stopped, the PTO put in "OFF," and the tiller inspected for damage before restarting. The equipment should never be left unattended while running. Operation in dark without adequate lighting is prohibited. The tiller should be operated from the operator's seat. Safety devices, interlocks, and shields must remain in place.
Transporting: When transporting the tiller, it should be raised to the transport position, and the PTO should be in the "OFF" position. Weight accessories are suggested to increase steering control.
Tilling: Operators should select the tractor's lowest ground speed and engage forward motion, then lower the tiller. Speeds should be slow over rough ground and hillsides to prevent overturn. When tilling loose ground, increase ground speed. Do not back up with the tiller down; raise it to transport position before backing up or turning sharply. Avoid stopping or starting suddenly when going up or downhill. Avoid steep hillside operation to prevent overturn; reduce speed when turning. Always look behind when backing up.
Installation: The installation process involves cleaning and greasing the PTO and axle bearing retainer shafts, positioning the PTO control to "ON" (with the engine off), depressing the locking collar on the chain box to slide it onto the transmission PTO shaft until it locks, moving the chain box bracket to "UP," guiding the universal drive shaft onto the axle bearing retainer shaft, aligning holes, and securing with a bolt and lock nut. The bracket is then connected to the tractor frame and chain box with bolts and lock nuts. The PTO control must be repositioned to "OFF" after installation.
Removal: Removal is the reverse of the installation process, ensuring the engine is "OFF" before putting the PTO control in "ON."

Maintenance Features

Regular maintenance is crucial for the longevity and proper functioning of the Rear PTO:

Greasing Shaft Bearings: Apply multi-purpose grease to the shaft bearings in the axle bearing retainer every 8 hours of use until grease comes out around the shaft.
Checking Chain Box Oil Level: Check the oil level in the chain box every 40 hours of use. Hold the gear box in a vertical position, remove the lower pipe plug, and fill with SAE 30W-40 oil until it is level with the hole. Replace the plug.
Axle Bearing Retainer Assembly: This involves cleaning the transmission drain plug area, draining transmission oil, raising and blocking the right drive wheel, removing the tire-wheel assembly, removing the nut and flat washer on the axle, removing the wheel hub with a puller, removing the axle key and bolts attaching the rear hitch to the axle bearing retainer, removing the four bolts holding the axle bearing retainer, cleaning all gasket residue, wiping the axle clean, applying grease to the seals, and securing the new axle bearing retainer casting.
Chain Box Assembly: This involves bolting the bracket to the rear side of the chain box, sliding the shaft into the universal yoke, securing with a bolt and lock nut, and sliding the shaft into the rear side of the chain box.

Storage Features

Proper storage helps protect the Rear PTO when not in use:

Removal: Remove the rear PTO chain box assembly with the drive shaft and rear PTO bracket from the tractor.
Lubrication: Clean and apply a film of grease on the rear universal yoke splines and the PTO shaft splines at the locking collar.
Positioning: Store the unit in a dry place, positioned so that oil does not run out of the vented plug at the top of the chain box.

Gravely REAR PTO - Page 3