725, 730, 730 EJECTOR & 735 Articulated Trucks, Pinion Locknut for Field Service [TIBU4630]

POWER TRAIN

DIFFERENTIAL & BEVEL GEAR GP

725, 730, 730 EJECTOR & 735 Articulated Trucks, Pinion Locknut for Field Service

CONFIDENTIAL TIBU4630-00

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TECHNICAL INFORMATION BULLETIN	September 21, 2005
Articulated Trucks	725 (AFX1-Up, B1L1-Up), 730 (AGF1-Up, B1M1-Up), 730 EJECTOR (B1W1-Up), and 735 (AWR1-Up, B1N1-Up)
	Component Code(s) 3256, 3258

SUBJECT: 725, 730, 730 EJECTOR & 735 Articulated Trucks, Pinion Locknut for Field Service

PROBLEM:

Recommended change in the pinion locknut used for field service

SOLUTION:

AVSpare recommends using a 184-4265 Locknut with 196-7878 Bolts in place of the 250-7858 Locknut for field service. The 250-7858 Locknut is used to secure the pinion gear in the differential and bevel gears on the axles identified in Table 1.

Table 1

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Effected Differential and Bevel Gear Groups
Machine	Front	Center	Rear
725	147-6790	188-1406	147-6790
730 & 730 EJECTOR	147-7380	188-1408	147-7380
735	Not Applicable	Not Applicable	175-0336

Illustration 1

184-4265 Locknut with 196-7878 Bolts

The 196-7878 Bolts have pre-applied thread lock compound. When installing the 184-4265 Locknut it is recommended to apply 9S-3263 Thread Lock Compound to the treads of the 196-7878 Bolts. If 196-7878 Bolts are not available, then 3F-8156 Bolts are a direct replacement. The 3F-8156 Bolts do not have pre-applied thread lock and 9S-3263 Thread Lock Compound must be applied to the threads.

INSTALLATION PROCEDURE:

Ensure that the input pinion bearings are adequately lubricated with oil then install the new locknut.

Tighten the locknut against the washer. Rotate the pinion several times while tapping the top of the pinion gently with a soft mallet to ensure that the bearings are fully seated. It may be necessary to tap both ends of the pinion shaft to ensure that the bearings are fully seated.

Continue to tighten the locknut until the rolling torque for the pinion is approximately 2.25 Nm (20 lb in). Rotate the pinion several times while tapping the splined shaft side with the soft mallet until the rolling torque is maintained at 2.25 Nm (20 lb in).

Loosen the locknut.

Re-tighten the locknut until the rolling torque is between 0.67 Nm (5.93 lb in) to 1.35 Nm (12 lb in). Rotate the pinion several times while tapping the shaft with the soft mallet until the rolling torque is maintained in the 0.67 Nm (5.93 lb in) to 1.35 Nm (12 lb in) range.

NOTE: The torques that are specified are for new bearings. For used bearings, limit the applied torque to one-half of the specified torque, 0.67 Nm (3.00 lb in) to 0.67 Nm (5.93 lb in).

Recheck the rolling torque. While measuring the rolling torque, make sure it does not "spike" or increase over 1.35 Nm. If there are spikes over 1.35 Nm (12 lb in) go back to Step 5 and use a smaller rolling torque value.

Tighten the four locking bolts to 30+/-7 Nm (22+/-5 lb ft). Tighten the bolts at least twice to ensure that the torque has been maintained on all four bolts. Measure the rolling torque.

NOTE: The torque on the four bolts is critical to the locknut holding capacity.

NOTE: An increase in preload torque of 2.5 Nm (22 lb in) can occur after tightening the 4 locking bolts on the adjusting nut for the pinion bearings. Max preload torque is 4 Nm (35.4 lb in).