2000/10/23 Caterpillar

Road Reclaimer/Soil Stabilizer:

RM-350B (PIN: 7FS1-UP)

Description of Change: A number of improvements have been made to the Mixing Chamber Group and the Rotor Stub Shaft. The changes will help prevent bolts from shearing at the connection between the disc and the disc housing. This type of failure may cause the mixing chamber and the rotor to hang up when you are raising or lowering the rotor.

Adaptable To: The improvements to the 148-6528 Mixing Chamber Group and the 138-9889 Rotor Stub Shaft that prevent 8T-9380 Bolts from shearing at the 148-2333 Disc and 1G-7861 Disc Housing are effective with S/N:7FS00166
.

The improvements to the 148-6528 Mixing Chamber Group and the 138-9889 Rotor Stub Shaft that prevent 8T-9380 Bolts from shearing at the 148-2333 Disc and 1G-7861 Disc Housing are adaptable to S/N:7FS1-00165
. A summary of the changes is listed below.

• A new 177-9873 Disc replaces the 148-2333 Disc. Additional bolt holes have been added to the disc for a stronger joint between the disc and the housing.

• A new 177-9872 Disc Housing replaces the 1G-7861 Disc Housing. Additional bolt holes have been added and the quality of the material for the housing has been improved in order to enhance the resistance to abrasions.

• New 8T-8917 Bolts and 8T-4223 Hard Washers replace 8T-9380 Bolts and 8T-5360 Washers that are used to connect the 177-9873 Disc and the 177-9872 Disc Housing. The bolt has been increased from a diameter of 7/16 inch to a diameter of 1/2 inch. The number of bolts and washers has been increased from 9 to 15 per side.

• A new 177-9875 Stub Shaft Shield replaces the 117-5235 Stub Shaft Shield. The quality of the material for the shield has been improved in order to enhance abrasion resistance. The clearance for the bolt to the disc housing has also been improved.

• A new 177-9876 Bearing Housing replaces the 138-8052 Bearing Housing. The quality of the material for the housing has been improved in order to enhance abrasion resistance. The new bearing housing has an induction hardened surface.

• A new 185-2935 Seal Housing replaces the 138-8053 Seal Housing. The seal housing has been improved in order to allow additional clearance.

• New 4K-5175 Bolts and 5P-7213 Hard Washers replace the 5P-2566 Bolts and 8T-4223 Hard Washers that are used on the seal housing.

• A new 190-3072 Bearing replaces the 121-0158 Bearing. The quality of the material for the bearing has been improved in order to enhance service life. The old bearing was made from fiber that was wound. The new bearing is made from hardened steel.

• A new 192-1895 Hub replaces the 144-3329 Hub. The new hub has an induction hardened surface for use with the new 190-3072 Bearing .

Rework Procedure

The following parts must be ordered in order to update the existing machines with the improvements. The rotor drum must be removed from the mixing chamber before updating with these parts. The rework procedure is identical for both sides of the machine.

Note: To reduce machine down time, all updates should be performed at the same time. Using the 190-3072 Bearing and the 192-1895 Hub together is recommended.

Illustration 1	g00744732
Mixing Chamber Group (1) 177-9873 Disc (2) 177-9872 Disc Housing (3) 8T-8917 Bolt (4) 8T-4223 Hard Washer (5) 190-3072 Bearing (6) 192-1895 Hub

Illustration 2	g00744733
Outer Rotor Chain Case Assembly (7) 177-9876 Bearing Housing (8) 185-2935 Seal Housing (9) 4K-5175 Bolts (10) 5P-7213 Hard Washers

Illustration 3	g00744735
Inner Rotor Chain Case Assembly (11) 177-9875 Stub Shaft Shield