Endurant HD / PACCAR TX-12 / PACCAR TX-12 PRO Main Case to PTO Interface

Date: November 11, 2025

Updated: April 27, 2026

Issue Description:

Gear noise identified when PTO is mounted (PTO backlash too tight / zero backlash). Main Case dimension at PTO interface (Lower Counter Shaft Center Line to PTO Mounting).

Containment/Corrective Action:

ECJV manufacturing began shipping qualified material (Main Cases) November 3rd, 2025.

K-4646 and K-4646-PAC (Transmission Main Cases) were put on quality hold and were cleared November 5th, 2025.

Service units (TA’s / TN’s) that were in stock at Eaton distribution centers (PDC’s) or REMAN were not inspected.

Affected Models/Population:

July 18th through current production, Endurant 12 speed / PACCAR TX-12 / TX-12 PRO transmission builds.

• ~Endurant HD / PACCAR TX-12 / PACCAR TX-12 PRO
• Transmission Serial Numbers Z0481904 to current production.

Current PTO manufacturers PTO sealing solutions: TRIG 2610, Endurant PTO Sealing Configuration Examples

Field Strategy:

Gasket shim recommendation as needed.

Bezares PTO:

Installed PTO Found and Backlash Under Specification (Too Tight / Zero Backlash):

• Bezares recommended backlash range 0.006” - 0.012” (0.15mm - 0.30mm).
• Bezares recommends discarding 0.015” metal gasket and use standard Aramid Fiber Gaskets to set proper PTO Backlash.
• Bezares Part Numbers. Available from Eaton Aftermarket Parts (ELC):
  • PT108010099: Aramid Fiber Gasket 0.012” (0.30mm).
  • PT108010003: Aramid Fiber Gasket 0.020” (0.50mm).
  • PT108010100: Aramid Fiber Gasket 0.040” (1.0mm).

Installed PTO and found backlash over specification (Too Loose / Excessive Backlash) call 1-800-826-4357 for next steps.

Muncie PTO:

Installed PTO and Found Backlash Under Specification (Too Tight / Zero Backlash):

• Muncie recommended backlash range 0.006” - 0.012” (0.15mm - 0.30mm).
• ECJV recommends installing Chelsea / Parker fiber paper gasket against the transmission and then using the original 0.055 Steel Gasket with Edge Molded Elastomer Seal.
• Chelsea / Parker fiber paper gaskets are not available at Eaton Aftermarket Parts (ELC). Call 1-800-826-4357 and follow the Endurant Prompts to request gaskets to be sent out no charge.
• Chelsea / Parker fiber paper gaskets are available commercially:
  • 35-P-15-1 Fiber Paper Gasket 0.010”
  • 35-P-15-2 Fiber Paper Gasket 0.020”
• Installed PTO and found backlash over specification (Too Loose / Excessive Backlash):
  • ECJV and Muncie have agreed to allow 0.020” backlash.
• Installed PTO and found backlash over 0.020” (Too Loose / Excessive Backlash) call 1-800-826-4357 for next steps.

Chelsea PTO:

Installed PTO Found and Backlash Under Specification (Too Tight / Zero Backlash):

• Chelsea recommended backlash range 0.006” - 0.012” (0.15mm - 0.30mm). Chelsea recommends discarding the push in place elastomer O-ring type seal. And then applying Chelsea / Parker fiber paper gaskets.
• Chelsea / Parker fiber paper gaskets are not available at Eaton Aftermarket Parts (ELC). Call 1-800-826-4357 and follow the Endurant Prompts to request gaskets to be sent out no charge.
• Chelsea / Parker fiber paper gaskets are available commercially:
  • 35-P-15-1 Fiber Paper Gasket 0.010”
  • 35-P-15-2 Fiber Paper Gasket 0.020”
• Installed PTO and found backlash over specification (Too Loose / Excessive Backlash):
  • ECJV and Chelsea have agreed to allow 0.0155” backlash.
• Installed PTO and found backlash over 0.0155” (Too Loose / Excessive Backlash) call 1-800-826-4357 for next steps.

Warranty Information:

Warranty Parts:

• None

Warranty Labor:

• None
• TRIG2610 and TRIG2620 updated December 2025 to include checking for backlash (Standard Procedure).

The material contained in this bulletin is product improvement information. Eaton Corporation is not committed to, or liable for, canvassing existing products.

FSUD: 4742