6 hours ago
The Legacy of the John Deere 550G
The John Deere 550G crawler dozer was introduced in the late 1980s as part of Deere’s G-series lineup, targeting mid-size earthmoving and forestry applications. Built with a direct drive transmission and pedal steering, the 550G was known for its simplicity, durability, and ease of maintenance. Deere & Company, founded in 1837, had by then become a global leader in agricultural and construction machinery. The 550G contributed to Deere’s strong market presence in North America, with thousands of units sold across logging, construction, and municipal fleets.
The 550G featured a 4-cylinder diesel engine, wet steering clutches, and internal expanding brake bands housed within the transverse case. Its compact design made it ideal for tight job sites, while its mechanical systems allowed for field repairs without specialized diagnostic tools.
Symptoms of Brake Band Wear and Failure
Operators often notice brake band issues when the machine becomes slow to respond to steering input or when one track fails to disengage properly. In the case of the 550G, a common symptom is delayed engagement on one side, requiring the operator to tap the opposite pedal to force hydraulic pressure into the affected circuit. This behavior suggests internal wear or misassembly of the brake and clutch components.
In one real-world case, a machine with over 13,000 hours exhibited poor left-side steering. Upon inspection, the brake band had reached the end of its adjustment range, and the clutch pack was found to be improperly assembled with missing friction linings.
Disassembly and Removal Procedure
Replacing the brake bands on a 550G requires partial disassembly of the drivetrain. The following steps outline the process:
Brake Band Variants and Compatibility
New brake bands may differ in appearance from the originals. For example, older bands may have grooves or textured linings, while newer replacements may be smooth. Deere’s updated part number AT142175 reflects a design change intended to provide more consistent pedal travel and wear characteristics.
Before installation, inspect the brake drum for scoring or grooves. If the drum surface is damaged, it should be resurfaced or replaced to prevent premature wear of the new band.
Clutch Pack Assembly and Common Mistakes
The 550G uses a multi-disc wet clutch pack for each steering side. A typical configuration includes:
Hydraulic Manifold and Sealing Rings
The clutch pressure manifold, located at the center of the transverse case, delivers hydraulic pressure to the steering clutch pistons. It is sealed by two rings that must be inspected for wear or scoring. These rings are often mistaken for metal but may be Teflon or composite material. Damaged seals can cause pressure loss and erratic clutch engagement.
Preventive Maintenance and Inspection Tips
In Alaska, a logger operating a 550G in dense forest terrain noticed the left track lagging during turns. After months of compensating with pedal tricks, he finally pulled the transmission and discovered a misassembled clutch pack and worn brake band. With new parts installed correctly and the hydraulic manifold resealed, the machine returned to full function—just in time for winter logging season.
Conclusion
Brake band replacement on the John Deere 550G is a complex but achievable task that requires attention to detail and a clear understanding of the machine’s internal systems. By following proper disassembly procedures, verifying clutch pack integrity, and inspecting hydraulic components, operators can restore precise steering and extend the life of this dependable dozer.
The John Deere 550G crawler dozer was introduced in the late 1980s as part of Deere’s G-series lineup, targeting mid-size earthmoving and forestry applications. Built with a direct drive transmission and pedal steering, the 550G was known for its simplicity, durability, and ease of maintenance. Deere & Company, founded in 1837, had by then become a global leader in agricultural and construction machinery. The 550G contributed to Deere’s strong market presence in North America, with thousands of units sold across logging, construction, and municipal fleets.
The 550G featured a 4-cylinder diesel engine, wet steering clutches, and internal expanding brake bands housed within the transverse case. Its compact design made it ideal for tight job sites, while its mechanical systems allowed for field repairs without specialized diagnostic tools.
Symptoms of Brake Band Wear and Failure
Operators often notice brake band issues when the machine becomes slow to respond to steering input or when one track fails to disengage properly. In the case of the 550G, a common symptom is delayed engagement on one side, requiring the operator to tap the opposite pedal to force hydraulic pressure into the affected circuit. This behavior suggests internal wear or misassembly of the brake and clutch components.
In one real-world case, a machine with over 13,000 hours exhibited poor left-side steering. Upon inspection, the brake band had reached the end of its adjustment range, and the clutch pack was found to be improperly assembled with missing friction linings.
Disassembly and Removal Procedure
Replacing the brake bands on a 550G requires partial disassembly of the drivetrain. The following steps outline the process:
- Remove the transmission to access the transverse case.
- Locate the pipe plugs under the steering clutches; behind them are Allen-head bolts used to preload the brake bands.
- Disconnect the hydraulic lines feeding the steering clutches.
- Remove the anchor bolts and pins securing the brake bands and steering clutches.
- Extract the steering clutch and brake band as a single unit from the rear of the transverse housing.
- On the bench, back off the brake adjuster wheel and separate the brake band from the anchor.
Brake Band Variants and Compatibility
New brake bands may differ in appearance from the originals. For example, older bands may have grooves or textured linings, while newer replacements may be smooth. Deere’s updated part number AT142175 reflects a design change intended to provide more consistent pedal travel and wear characteristics.
Before installation, inspect the brake drum for scoring or grooves. If the drum surface is damaged, it should be resurfaced or replaced to prevent premature wear of the new band.
Clutch Pack Assembly and Common Mistakes
The 550G uses a multi-disc wet clutch pack for each steering side. A typical configuration includes:
- 7 steel clutch discs
- 6 friction linings
Hydraulic Manifold and Sealing Rings
The clutch pressure manifold, located at the center of the transverse case, delivers hydraulic pressure to the steering clutch pistons. It is sealed by two rings that must be inspected for wear or scoring. These rings are often mistaken for metal but may be Teflon or composite material. Damaged seals can cause pressure loss and erratic clutch engagement.
Preventive Maintenance and Inspection Tips
- Clean the suction screen regularly to remove debris from worn clutch or brake materials.
- Inspect all linkages under the operator’s seat for wear or misalignment.
- Replace worn bearings in the control rods to maintain precise steering input.
- Use Deere’s Operation and Test Manual TM1403 to verify adjustment procedures and hydraulic pressures.
In Alaska, a logger operating a 550G in dense forest terrain noticed the left track lagging during turns. After months of compensating with pedal tricks, he finally pulled the transmission and discovered a misassembled clutch pack and worn brake band. With new parts installed correctly and the hydraulic manifold resealed, the machine returned to full function—just in time for winter logging season.
Conclusion
Brake band replacement on the John Deere 550G is a complex but achievable task that requires attention to detail and a clear understanding of the machine’s internal systems. By following proper disassembly procedures, verifying clutch pack integrity, and inspecting hydraulic components, operators can restore precise steering and extend the life of this dependable dozer.
