Power Take Off Installation

Preparation

Do not disengage the clutch before conducting the power take off installation on the engine. Disengagement allows the clutch plates to slip out of the correctly aligned positions.
If the facings have become misaligned, they may be realigned by using the drive ring as a gauge.

Flywheel and Flywheel Housing Alignment Checks

It is strongly recommended that the dial indicator checks be made prior to installation of the PTO, especially on new engines or when bearing failures or shaft wear were found after the previous PTO was removed and examined for cause of failure.

Lubrication Required Before Installation

Lubricate as follows before installation:

Release bearing: (except non-greasable type)
Bronze and greasable ball-type release bearing: With a hand operated grease gun, add 1 or 2 pumps of grease per 8-10 hours of operation (or until grease begins to weep from the I.D. of the bearing and the release sleeve. Rotate the shaft (by hand) while adding grease. Do not over-grease!!

Release bearing: (non-greasable type)
Non-greasable ball bearing type release bearing:
Sealed bearing- no lubrication required.

Release sleeve used with non-greasable bearing: Using a hand operated grease gun, add 1 or 2 pumps of grease per 8-10 hours of operation (or add grease until grease begins to weep from between the release sleeve and the shaft). Rotate the shaft (by hand) while adding grease. Do not over-grease!!

Main bearing: With a hand operated grease gun, add 1 or 2 pumps of grease while rotating the shaft (by hand), or until grease weeps from the labyrinth seals around the shaft at either end of the bearing housing.

Pilot bearing lube passage: Some PTOs have a hole drilled through the length of the shaft to provide lube to the pilot bearing. The grease fitting may be located either at the end or to the side of the output shaft. Add grease until the center passage is filled with grease. Be sure that the shipping plug is removed from the pilot bearing end of the shaft prior to installation.

Cross shaft: With a hand operated grease gun add 1 or 2 pumps of grease into each of the grease fittings located in the PTO housing, near each end of the cross shaft.

Install the PTO on the Engine

Install the drive ring on the engine flywheel. Be sure that the ring is seated in the locating bore. Use USA SAE Grade 5 bolts (or equivalent) with lockwashers. Torque the bolts according to the chart below.

Clutch Size and TypeBolt SizeTorque  Specification
6.5″ HE5/16- 1815-18 ft-lbs (20- 24 Nm)
7.5″ HE5/16- 1815-18 ft-lbs (20- 24 Nm)
8″ HE3/8- 1626- 35 ft-lbs (35- 43 Nm)
10″ HE3/8- 1626- 35 ft-lbs (35- 43 Nm)
11″ S HE3/8- 1626- 35 ft-lbs (35- 43 Nm)
11.5″ HE(DP)3/8- 1626- 35 ft-lbs (35- 43 Nm)

Use the engine manufacturer’s torque specifications if different from the above. Some engines use metric bolts. Refer to engine manufacturer’s torque specifications.

(For greasable pilot bearing ONLY). If a pilot bearing adapter is used on the flywheel, be sure the
mating surfaces between the adapter and the flywheel face are sealed, to prevent loss of grease from the pilot
bearing grease cavity due to vacuum or centrifugal force. Loctite 515 or equivalent is suggested.

Proceed as follows:
For greasable pilot bearing ONLY: (bearing has a grease shield on 1 side only) Pack the flywheel pilot bearing cavity with grease. Install the pilot bearing in the flywheel or adapter with the grease shield of a greasable bearing towards the PTO and clutch. Be sure that the pilot bearing spacer, if used, is in place. Two types of spacers may be used. Spacers may be installed in the flywheel to keep the pilot bearing from going too far into the bore in the flywheel, and a spacer may be used on the pilot end of the PTO shaft between the pilot bearing and the PTO to help maintain proper pilot bearing location in the flywheel bore.

For non-greasable pilot bearing ONLY: (bearing has 2 grease seals.)

Non-greasable, double-sealed pilot bearings require no re-lubrication and may be installed in the flywheel or
adapter with either side toward the PTO and clutch. The shaft should have no grease fittings. If it does,
remove the grease fitting(s) and replace with pipe plugs as a precaution to insure grease is not forced into the
pilot bearing cavity of the flywheel. A build-up of pressure caused by forcing grease into the cavity can cause
the pilot bearing to be forced out of the flywheel, resulting in a bearing or shaft failure.

Install the PTO with the cross shaft in a horizontal position. Install two 5″ long guide bolts in the flywheel housing holes, located approximately at the 3 o’clock and 9 o’clock positions. Position the PTO on the guide bolts to help align the unit and support the weight while the mounting bolts are installed. Start the PTO shaft in the pilot bearing. Carefully align the clutch facing teeth with the teeth in the drive ring. Temporarily install longer bolts in 4 bolt holes 90 degrees apart, and tighten the bolts alternately and evenly to draw the PTO housing toward the flywheel housing. Replace the longer bolts with shorter ones as necessary, and tighten to draw the PTO into place. Then remove the temporary bolts and guide bolts, and replace them with proper mounting bolts. Install bolts and lockwashers. Use USA SAE Grade 5 bolts (or equivalent) with lockwashers. Torque bolts according to the following chart.

NOTE: Many engines use metric threads, so the below chart would not be applicable. Do not use bolts made with U.S. threads in holes with metric threads. The threads will be damaged, rendering them unusable.

SAE Housing SizeBolt SizeTorque Specification
#17/16-1442-50 ft-lbs (57 – 68 Nm)
#23/8- 1626-35 ft-lbs (32 – 43 Nm)
#33/8- 1626-35 ft-lbs (32 – 43 Nm)
#43/8- 1626-35 ft-lbs (32 – 43 Nm)
#53/8- 1626-35 ft-lbs (32 – 43 Nm)
#63/8- 1626-35 ft-lbs (32 – 43 Nm)

Use the engine manufacturer’s torque specifications if different from the above torque recommendation.

Rap the output end of the shaft with a soft mallet to relieve any pre-load on the engine crankshaft that may have built up as a result of the pilot bearing’s fit on the shaft pilot.

Correct Handle Installation Position

Install the clutch handle or release mechanism. Position the handle so that it is pointing either straight up or straight down when the clutch is in the engaged position. Positioning the lever vertically minimizes loading on the release bearing. If an altered or special clutch engagement mechanism is used (remote linkage mechanism is not recommended), be sure there is not pre-load on the release bearing either sideways or toward the engaged or released position. There should be no pre-load on the cross shaft in any direction, forward, rearward or sideways. A torsional and forward or rearward load (only) will be applied (only) during the engagement or disengagement cycle.

Check Clutch Engagement Pressure

The clutch was properly adjusted at the factory. However, due to variables created by first-time engagements, the clutch engagement pressure should be rechecked to insure proper clutch engagement pressure at the time of installation.