To provide assurance that foreign material will not enter final drive assemblies, a new design axle shaft oil seal with improved sealing characteristics has been adopted for Model "40" Crawler Tractors.

AM2723T SEAL FOR TRACTORS WITH SERIAL No. 4OC-68814 AND UP

Effective with Tractor Serial No. 4OC-68814, a new oil seal identified by the part number AM2723T was adopted for production tractors and is now available as a replacement part item. This seal differs from the AM973T oil seal previously used in that it is designed with a multiple lip sealing arrangement instead of an oil-impregnated felt retainer (Figure 29A). The triple lip sealing arrangement very effectively seals final drives against foreign material.

It is of the utmost importance that the AM2723T oil seal be properly positioned on the flanged axle shaft. The three outer sealing lips must face outward toward axle flange to seal foreign material from final drive. The single spring-loaded inner lip must face inward to seal oil in the final drive assembly.

To assure that the three outer lips of the seal are properly positioned, a special seal installation tool has been designed (Figure 29B). The special tool can be obtained by ordering AM2774T Assembly Tool for Oil Seal. The AM2723T oil seal cannot be satisfactorily installed without this tool, and assembly should not be attempted under any circumstances unless the tool is used.

A new seal retaining casting is used in conjunction with the AM2723T oil seal. The new retaining casting provides additional clearance for the sealing lips and has a larger inner diameter to permit use of the AM2774T seal installation tool. The new retainer, Part No. M2878T was effective in production with Serial No. 4OC-68017. The M2878T retainer will also fit all Model "40" Crawler Tractors beginning with Serial No. 4OC-62264, and will accommodate the AM973T, AM2775T, and AM2723T oil seals. However, the new retainer must be used whenever the AM2723T oil seal is used. The M2878T retainer is furnished instead of the M2366T retainer as a replacement part.

Installation of AM2723T Oil Seal. (40C-68814- )

1. Remove the old seal from M2878T retainer and position new AM2723T oil seal in retainer with triple lip side of seal facing toward bottom of retainer.
2. Using suitable tool, press seal to bottom of counterbore in M2878T seal retainer.
3. Completely fill all cavities between lips of seal with Lubriplate (107) or a good grade of gun grease.
4. Inspect seal bearing surface on axle shaft and make sure it is smooth and free from rust. Replace axle if necessary.
5. Slide seal and retainer assembly over AM2774T seal installation tool as shown in Figure 30A, until rear face of seal is against shoulder on sleeve of tool.
6. 
7. Slide nose of assembly tool free from sleeve and slip sleeve, oil seal, and retainer assembly into position on AM2136T flanged axle assembly.
   NOTE: The oil seal retainer attaching cap screws and lock washers should be placed in position in the attaching holes in the retainer before assembly tool sleeve is removed from oil seal and retainer.
8. Hold seal and retainer assembly against radius of flanged axle and carefully withdraw assembly tool sleeve, using a rotary action. This procedure will leave the three lips of the AM2723T oil seal facing outward as shown in Figure 30B.
   CAUTION: Do not move the oil seal and retainer assembly any more than is absolutely necessary, as excessive movement may partially invert the seal lips on the axle.
9. Install bearing cup and cone on the axle and carefully assemble axle in final drive housing.

For additional service information relative to assembly of final drives and bearing preloads, refer to the Model "40" Series Service Manual (SM-2013), pages 145-16-3 and 145-16-4.

AM2775T SEAL FOR TRACTORS WITH SERIAL No. 4OC-62264-40C-68813

For tractors in the Serial No. range between 4OC-62264 and 4OC-68813, a new AM2775T oil seal is being furnished as replacement instead of the AM973T seal formerly used. The new seal is designed with two neoprene sealing lips instead of the single neoprene lip and felt retainer in the AM973T seal.

Installation of AM2775T Oil Seal (40C-62264-40C-68813)

1. Remove the old seal from M2366T seal retainer and position new AM2775T double lip oil seal in retainer with lips of oil seal facing toward bottom of retainer.
2. Use suitable tool and press seal to bottom of counterbore in M2366T seal retainer.
3. Completely fill all cavities between lips of oil seal with Lubriplate (107) or a good grade of gun grease.
4. Inspect seal bearing surface on axle shaft and make sure it is smooth and free from rust. Use shim stock to protect oil seal and install retainer and oil seal assembly on flanged axle.
   NOTE: In event the M2878T seal retainer is used, the AM2774T seal installation tool is recommended for installing the AM2775T seal in lieu of shim stock as mentioned in step 4.
   CAUTION: Be sure lips of oil seal face toward flange on axle.

AM2773T SEAL FOR TRACTORS WITH SERIAL No. 4OC-60001-40C-62263

The AM2773T oil seals are now furnished as parts on Model "40" Crawler Tractors in the serial number range from 4OC-60001 to 4OC-62263. These seals differ from the AM776T seals previously used in that they have two neoprene sealing lips instead of a single neoprene lip and felt retainer.

Installation of AM2773T Oil Seal (40C-60001-40C-62263)

1. Remove the old seal from AM775T axle bearing quill and position new AM2773T double lip oil seal in quill with lips of oil seal facing toward bottom of quill.
2. Using an M650T driver, drive seal to bottom of counterbore in AM775T quill.
3. Completely fill cavities between lips of oil seal with Lubriplate (107) or a good grade of gun grease.
4. Inspect seal bearing surface on axle shaft and make sure it is smooth and free from rust. Using shim stock to protect oil seal, install bearing quill and oil seal assembly on axle shaft.
   CAUTION: Be sure lips of oil seal face toward sprocket driving hub when seal is installed on axle.

To summarize, oil seals furnished for service parts on Model "40" Crawler Tractors in the various serial number ranges are as follows: