CYLINDER GP-BOOM 3206522 - Caterpillar

7251, 7261 Marine TransmissionsSUPPLEMENT: 11/16/87SERVICE MAGAZINE; AUGUST 24, 1987; PAGE 11; "More Accurate and Easier Method To Adjust 8T1815 Or 6L5438 Main Shaft Bearing" on 3192, 7251, 7261 Marine Transmissions.The note on Page 13 has an incorrect dimension. The note should read: The sides of the spacer must be parallel to each other within 0.025 mm (0.001")--------------- END SUPPLEMENT ---------------Reference: Service Magazine; March 25, 1985; Page 12, "New Main Shaft Bearing Assembly Has Reduced End Play" in 7251 and 7261 Marine Transmissions. Service Magazine; May 27, 1985; Page 11, "Correct Procedure To Check Tapered Bearing End Clearances" for all applications.Reference: Service Manual Disassembly And Assembly Modules for Above Marine Transmissions. The first Reference Article announced an improved 8T1815 Bearing Assembly on the main shaft of the 7251 and 7261 Marine Transmissions. (The same bearing is also serviced for the 3192 Marine Transmissions.) Cross out the last paragraph of this article, and refer to this new article. A more accurate adjustment procedure with a fabricated preloading device is now available and should be used when the bearing end clearance is set. This same procedure and the same spacer thickness can also be used on the former 6L5438 Bearing Assembly if it does not need to be replaced.
Refer to second Reference Article and, after the subtopic, write "Except 3192, 7251, 7261 Transmissions", and cross out the first paragraph referring to the earlier Service Magazine article. Also, add a note to the Service Manual modules referring to this new article.If the bearing end clearance is too much, the half of the bearing which is unloaded can have a bearing separator failure. The fabricated preloading device is bolted to both sides of the 8T1815 Bearing Assembly to provide a constant preload during the entire procedure.
Make all the necessary pieces for the preloading device as shown in Illustration 1. Also, see Illustration 3 for the load springs and additional hardware needed.
Illustration 1. Details for making the load plate and the two half-moon plates.Measurement And Adjustment Procedure:
1. Assemble only the parts shown by the shading in Illustration 2. Do NOT install the spacer between