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TRACK MANAGEMENT
Management & Merchandising
Elevated sprocket machines: D4H - D7R
Low sprocket machines: D3 - D7G, 943 - 973 and 933 - 977
Projected Bushing Life
to 100% Worn Track Seal Recommendation**
0 to 2,000 SMU Reuse seals during bushing turn.
2,000 to 4,000 SMU Replace seals during bushing turn.
4,000 to 6,000 SMU Replace seals at 4,000 SMU intervals.
Consider turning bushings before 100% wear.*
6,000 SMU and greater Replace seals at 4,000 SMU intervals.
Elevated sprocket machines: D8L - D11R (Except Sleeve Bearing Track)
Low sprocket machines: D8 - D9H
Projected Bushing Life
to 100% Worn Track Seal Recommendation**
0 to 4,000 SMU Replace seals during bushing turn.
4,000 to 6,000 SMU Replace seals at 4,000 SMU intervals.
Consider turning bushings before 100% wear.*
6,000 SMU and greater Replace seals at 4,000 SMU intervals.
D11N, D11R with Sleeve Bearing Track
Projected Bushing Life
to 100% Worn Track Seal Recommendation**
0 to 6,000 SMU Replace seals during bushing turn.
6,000 to 8,000 SMU Replace seals at 6,000 SMU intervals.
Consider turning bushings before 100% wear.*
8,000 SMU and greater Replace seals at 6,000 SMU intervals.
* The decision whether or not to turn bushings (versus reseal only) before 100% wear should depend on projected link life.
For example, if projected link life for a D8R is less than 8,000 SMU, achieve full link life with a bushing turn at 4,000 SMU
even if the bushings are only 50% worn. If projected link life is over 8,000 SMU, a cost per hour analysis should determine
whether to turn bushings or to reseal at 4,000 SMU.
** EXCEPTION: When a bushing is replaced, always replace the seals used with that bushing.
NOTE: Average track seal life is about 4,000 SMU, but life varies considerably depending on application and underfoot
conditions. Actual seal life ranges from as low as 2,000 SMU to over 5,000 SMU. Generally, seal life will be shorter on
machines working in severe conditions. To maximize pin & bushing life, around 3,500 SMU begin checking on a
regular basis for dry joints. Resealing should be considered if joints become dry.
Track Seal Replacement
Recommendations
Good track seal maintenance practices
assure maximum life for tracks. Use the
following guidelines for determining when
to replace track seals.
Rigid Track Seals
All track type machines with Sealed &
Lubricated Track currently use Rigid
Track Seals. This type of seal has excel-
lent sealability, but its life is limited, even-
tually allowing oil to leak and joints to
become dry. To maximize undercarriage
life, replace these seals according to the
intervals in the following chart.
Post Turn Seals
This type of seal, introduced first on the
D11, was designed for use during a pin &
bushing turn or track reseal. Post Turn
Seals are smaller in diameter than standard
seals so that they seal against an unused
bushing surface away from the original
seal groove.
Use Post Turn Seals when bushing end
grooving does not exceed the limit of the
4C8613 (formerly 8T9291) end grooving
gauge. If bushing end grooving exceeds
the limit of this gauge, replace the bushing
using a new standard seal.