Complaint:
The transmission makes a third gear start even though first gear is commanded. It may also bind up in reverse and manual low, after disassembly inspection reveals that the 3-4 clutch is badly burnt.
Cause:
The rear stator bushing is worn.
Correction:
When the rear stator bushing wears, a cross feed takes place across the input shaft sealing rings. The feed hole on the input shaft closest the drum is the lube circuit, the lube circuit oil will cross feed into the feed hole above it which is the 3-4 clutch circuit. The constant flow of lube oil into the 3-4 clutch feed circuit puts a drag on the clutch which not only burns it but causes a third gear start.
The bind in manual low is caused by the fact that when the low/reverse clutch is applied and the 3-4 clutch is applied by lube oil a bind up will occur which will also cause the bind in reverse. This condition gets worse as the transmission warms up to normal operating temperature. It is a good idea to replace both the front and rear stator bushings, not only to prevent the above complaint but to also insure that the input shaft spins centerline to its related components.
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