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An International TD8E dozer, recently revived after sitting idle in a barn for 3–5 years, began exhibiting a puzzling transmission issue. The machine started and ran well, steering properly and shifting smoothly through all gears. However, after driving a short distance, it would begin to slow down, with the driveshaft visibly decelerating. The engine maintained full RPM and showed no signs of fuel starvation or surging, ruling out engine-related causes.

Transmission Type and Fluid Check Protocol

The TD8E was confirmed to have the short transmission variant. This distinction matters because fluid level checks differ between the short and long transmission types:

  • Long transmission: Fluid must be checked while warm and running, using a dipstick under the floorboards.
  • Short transmission: Fluid level can be checked statically, but still requires warm-up for accurate assessment.

In this case, the fluid had been changed, the screen cleaned, and no debris was found. The level appeared correct, but symptoms persisted.

Suspected Causes: Air Intrusion and Suction Loss

The operator suspected a cracked hose or failed O-ring allowing air into the transmission suction line. This is a plausible scenario, especially after long-term storage. Air intrusion can cause:

  • Cavitation in the pump
  • Loss of hydraulic pressure
  • Torque converter slippage
  • Driveshaft deceleration under load

One technician noted that a fogged clutch pressure gauge prevented confirmation of pressure loss, but recommended replacing or cleaning the gauge to monitor clutch pack engagement.

Torque Converter Behavior and Heat Effects

As the machine warms up, fluid viscosity decreases. If the torque converter or transmission pump is marginal, this can lead to:

  • Reduced pressure at operating temperature
  • Incomplete clutch engagement
  • Sluggish or slipping drive response

A retired operator recalled a similar issue on a Dresser TD8E where the torque converter would “fade” after 15 minutes of work. The fix involved replacing a worn converter seal and flushing the system to remove varnished fluid.

Fuel System Ruled Out

Although one technician suggested a fuel supply issue, the engine maintained full RPM and showed no signs of power loss. This ruled out injector starvation or governor malfunction. The problem was isolated to the drivetrain.

Recommended Diagnostic Steps

To pinpoint the failure, the following steps were advised:

  • Replace or clean the clutch pressure gauge to monitor live readings
  • Inspect all suction hoses for cracks, dry rot, or loose clamps
  • Check for collapsed internal liners in reinforced hoses
  • Warm up the machine and observe pressure behavior over time
  • If pressure drops, consider rebuilding the transmission pump or inspecting the torque converter inlet screen

Field Anecdote: Hose Collapse After Storage

A technician in Michigan shared that after reviving a TD8E from storage, a reinforced suction hose collapsed internally due to dry rot. The outer layer appeared intact, but the inner liner had delaminated, choking flow under vacuum. Replacing the hose restored full drive function.

Final Thoughts

The TD8E’s transmission slowdown after warm-up is likely caused by fluid starvation due to air intrusion or suction loss. Long-term storage can degrade seals and hoses, leading to subtle but critical failures. With methodical pressure testing, hose inspection, and torque converter evaluation, the issue can be resolved. For legacy machines like the TD8E, understanding fluid dynamics and warm-up behavior is key to keeping them productive in the field.

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