FRAME AS 4391944 - Caterpillar

Illustration 8 g02272336
Check to make sure that the drum is concentric with the inside bore.
Illustration 9 g02272457
Check to make sure that the drum is concentric with the inside bore. The runout must be less than 0.127 mm (.005 inch).
Illustration 10 g02272577
A brake drum on a horizontal lathe with a boring bar (used as the cutting tool).The specifications in Table 2 give the needed machined surface finish of 3.2 to 4.1 µm (125 to 160 µ inch). Use an American Standard (A.N.S.I.) tool, a TNMG-432, C-2 Grade Carbide Cutter, with a 0.762 mm (.030 inch ) tip radius. Table 2 also lists feed and speed rates needed for drums with different diameters. Do not machine more than the "Use Again" diameter units given in Table 2.During the machining procedure:
Remove enough material so that a minimum of 80% of the brake drum outside diameter is a newly machined surface. Some small groves are acceptable, however, all small cracks must be removed by the machining process.
Use vernier calipers to measure the outside diameter of the brake drum. If this dimension is not smaller than the minimum drum diameter, the drum can be used again.
Table 2
Specifications To Machine Track-Type Tractor Brake Drums    
Depth Of Cut:
0.381 mm (.015 inch)
Feed Per Revolution:
0.165 mm (.0065 inch)
Surface Finish:
3.2 to 4.1 µm (125 to 160 µ inch)    
Model     Typical Brake Drum Part Number     Outside Diameter
(New)     "Used Again"
(Minimum Diameter)     Lathe Speed
(RPM)    
D3, D3B, D3C, D4C, 931, 931B, 931C     6S-3203    
330.15 mm (12.998 inch)    
326.97 mm (12.873 inch)     70    
D4D, D4E, 941, 941B, 955L, 955K     7K-8237    
330.15 mm (12.998 inch)    
326.97 mm (12.873 inch)     70    
D5B     8P-0203    
425.45 mm (16.750 inch)    
422.27 mm (16.625 inch)     55    
D6C, D6D, D6E, D6E, D6G, D6N, 973D, 977, 977K, 977L     2S-7603    
425.45 mm (16.750 inch)    
422.27 mm (16.625 inch)     55    
D6N, D6T, D8T     136-1595    
353.56 mm (13.919 inch)    
350.38 mm (13.795 inch)     55    
D7F, D7G, 572G, 983, 983B     5M-1998    
425.45 mm (16.750 inch)    
422.27 mm (16.625 inch)     55    
D8H, 583H     8H-2434    
447.68 mm (17.625 inch)    
444.50 mm (17.500 inch)     50    
D8K, 583K     2P-9038    
447.68 mm (17.625 inch)    
444.50 mm (17.500 inch)     50    
D9G, D9H, 594H     2M-6984    
501.65 mm (19.750 inch)    
498.48 mm (19.625 inch)     45    Procedure to Anneal
This procedure makes iron softer by the application of heat.
Heat the drum in an oven to a temperature between 400 and 485°C (750°F and 900°F) for approximately 1 minute.Note: Using a blow torch to heat the drum is NOT recommended because of the possibility of brake drum distortion. If a blow torch has been used, the drum must be checked for distortion while still installed in the lathe.
Allow the drum to cool to room temperature. (Using water to cool the drum can cause stresses in the drum.)
Use