hayden
Veteran Member
The dealer I bought from also said that reversing generates more wear. He said that when running forward the grouser pads shed the dirt, where in reverse then draw it into the drive mechanism. I haven't looked at the way they work myself to see if I believe this explaination, but it sure sounded good.
Speaking of wear, someone posted a link to Crawler Heaven which has some great info on measuring wear. Keep in mind, however, that newer machines have what are referred to as Sealed And Lubricated Tracks, or SALT tracks. These wear differently than the traditional dry pin and bushing design.
On tradition dry units, both the outer and inner surface of the bushings wears. The outer surface wears from contact with the drive gear, and is accompanied by wear of the drive sprocket teeth. Badly worn sprocket teeth have sharp rather than blunt, rounded points. Badly worn bushings result in out of round surfaces, and sometimes wear all the way through to the pin. You can feel the wear with your hand, and can measure it with calipers.
The inner inner surface of the bushing and the pin inside it wear together from contact with each other. The pins also wear fom contact with the inside of the bushing. This wear can be measured by the link to link spacing in the track since the track lengthens as the pins and inner bushings wear.
Crawler Heaven lists the link to link dimensions and outer bushing dimensions for figuring out waer limits, but it only applies to unsealed tracks.
On SALT tracks, the bushing and pin are lubricated and sealed and as a result have no appreciable wear. The only problems occurs if the seal is violated and you end up with a dry pin/bushing, but they are supposed to last the life of the tracks. A squeeking joint is an indicator of seal failure and repair involved replacing that joint.
On SALT tracks, because the pins and inner bushings don't wear much, all the wear is concentrated on the outer bushings and interfacing sprocket teeth. In theory they are designed to wear out at the same time so overall wear can be judged by the condition of the sprocket teeth. One wrinkle is that the bushings, which are pressed into the link and don't rotate, wear on only one side. One life-extending measure is to press out the bushings and rotated them 180 degrees before reinstalling them. This effectively doubles the life of the bushing. But, it's not that simple, because the sprocket will be worn when you rotate the bushings which results in faster wear of both after rotation. Also, rotating the bushings is no simple task, requiring dismantling of the track and very large specialty presses. There appear to be differnt camps on how to get the most cost-effective life out of SALT tracks. Some people run them without touching them until the sprockets are gone and/or the bushings are worn through, then replace the tracks and sprockets completely. Others run for about half the sprocket life, rotate the bushings, then run 'till the tracks drop.
Anyway, hopefully this will speed others on the learning curve I went through, and explain why track lengther for newer dozers are not listed on Crawler Heaven.
Cat has a new track design with some fancy name where the bushing DO rotate during normal operation. The idea is that the wear is spread over the bushing surface and eliminates rotation as a maintenance procedure. Supposedly there is no track maintenance until the sprockets are shot, at which point you replace everything.
Ahh, the things you learn owning tractors and other heavy equipment.....
Speaking of wear, someone posted a link to Crawler Heaven which has some great info on measuring wear. Keep in mind, however, that newer machines have what are referred to as Sealed And Lubricated Tracks, or SALT tracks. These wear differently than the traditional dry pin and bushing design.
On tradition dry units, both the outer and inner surface of the bushings wears. The outer surface wears from contact with the drive gear, and is accompanied by wear of the drive sprocket teeth. Badly worn sprocket teeth have sharp rather than blunt, rounded points. Badly worn bushings result in out of round surfaces, and sometimes wear all the way through to the pin. You can feel the wear with your hand, and can measure it with calipers.
The inner inner surface of the bushing and the pin inside it wear together from contact with each other. The pins also wear fom contact with the inside of the bushing. This wear can be measured by the link to link spacing in the track since the track lengthens as the pins and inner bushings wear.
Crawler Heaven lists the link to link dimensions and outer bushing dimensions for figuring out waer limits, but it only applies to unsealed tracks.
On SALT tracks, the bushing and pin are lubricated and sealed and as a result have no appreciable wear. The only problems occurs if the seal is violated and you end up with a dry pin/bushing, but they are supposed to last the life of the tracks. A squeeking joint is an indicator of seal failure and repair involved replacing that joint.
On SALT tracks, because the pins and inner bushings don't wear much, all the wear is concentrated on the outer bushings and interfacing sprocket teeth. In theory they are designed to wear out at the same time so overall wear can be judged by the condition of the sprocket teeth. One wrinkle is that the bushings, which are pressed into the link and don't rotate, wear on only one side. One life-extending measure is to press out the bushings and rotated them 180 degrees before reinstalling them. This effectively doubles the life of the bushing. But, it's not that simple, because the sprocket will be worn when you rotate the bushings which results in faster wear of both after rotation. Also, rotating the bushings is no simple task, requiring dismantling of the track and very large specialty presses. There appear to be differnt camps on how to get the most cost-effective life out of SALT tracks. Some people run them without touching them until the sprockets are gone and/or the bushings are worn through, then replace the tracks and sprockets completely. Others run for about half the sprocket life, rotate the bushings, then run 'till the tracks drop.
Anyway, hopefully this will speed others on the learning curve I went through, and explain why track lengther for newer dozers are not listed on Crawler Heaven.
Cat has a new track design with some fancy name where the bushing DO rotate during normal operation. The idea is that the wear is spread over the bushing surface and eliminates rotation as a maintenance procedure. Supposedly there is no track maintenance until the sprockets are shot, at which point you replace everything.
Ahh, the things you learn owning tractors and other heavy equipment.....
