1981/05/20 Caterpillar


Hardened Nuts And Higher Torque Now Used In Ahead And Astern Clutch Groups

Usage:


7271 Marine Transmission

SUPPLEMENT: 09/16/81

ENGINE NEWS, MAY 20, 1981, PAGE 8.

In the article "Hardened Nuts And Higher Torque Now Used In Ahead And Astern Clutch Groups", the part numbers are wrong. The new, high-torque nut is 1F7958 and the former general-purpose nut is 1D4719.

Change the first sentence after "ADAPTABLE AS:" to:

"The new 1F7958 Nuts are direct replacements for the former 1D4719 Nuts in this application.

Change "1D4719" to "1F7958" in both the illustration caption and the illustration nomenclature.

--------------- END SUPPLEMENT ---------------

Description of Change: Hardened nuts and a higher torque value are now used in the ahead and astern clutch groups for 7271 Marine Transmissions (see illustration). The new nuts are tightened to 135 ± 15 N·m (100 ± 11 lb ft). The increased torque will give a tighter connection between the parts in the clutch groups.

Formerly, nuts which were not hardened were used on the clutch studs and they were tightened to 100 ± 15 N·m (75 ± 11 lb ft).

Adaptable As: The new 1F7958 Nuts are direct replacements for the former 1D4719 Nuts in this application. Eight nuts are required for each 7271 Transmission.


Location of 1D4719 Nuts

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