Analysis Of Leakage

Power Transfer Unit (PTU)


Analysis of Leakage

NOTE: Inspection of the seal's mating journal should be performed every time a seal is replaced. The mating part/journal should be replaced if it has any of the following conditions: Radial wear groove that can be felt by running a finger nail across it where seal lip runs. Scratches, pitting, galling, nicks or other shaft damage under or near where the seal lip runs. Discoloration or coked oil on the shaft where the seal lip runs. Shaft corrosion under or near where the seal lip runs. Sharp edges or burrs on the shaft lead in chamfer. NEVER use emery cloth on journal finishes, replace the part.

The PTU (Power Transfer Unit) may leak different color fluids, red oil leak for an automatic transmission fluid and brown/black gear lube for PTU (Power Transfer Unit) fluid. The PTU (Power Transfer Unit) seals prevent these types of fluids from leaking. It is important to note which color of fluid is leaking to determine the most appropriate service procedure.

PTU (Power Transfer Unit) Leaks From the RH Side

NOTICE: Remove and replace leaking seals using the information found in the Intermediate Shaft Seal and Deflector or Cover Seal replacement procedure. The specified tools called out in this procedure will allow seal replacement without causing damage to the Power Transfer Unit (PTU) casing/drive gear.

If the leak is red automatic transmission fluid, the PTU (Power Transfer Unit) intermediate shaft seal needs replacement. This is inside the bore of the PTU (Power Transfer Unit) shaft behind the deflector. Refer to the Intermediate Shaft Seal and Deflector procedure.

If the leak is brown/black gear lube, the PTU (Power Transfer Unit) larger cover seal needs replacement. This is located on the PTU (Power Transfer Unit) cover behind the deflector. Refer to Cover Seal procedure.

NOTE: The following figure is for reference only. The kit also includes a special tool (not pictured) that is used during seal installation only and is not intended to be left in the PTU (Power Transfer Unit) as a sealing device.










PTU (Power Transfer Unit) Leaks From the LH Side

If the leak is the red automatic transmission fluid, the compression seal needs replacement. This is between the PTU (Power Transfer Unit) and transmission. Refer to Power Transfer Unit (PTU) in the Removal.

If the leak is brown/black and venting fluid from the top of the PTU (Power Transfer Unit), the PTU (Power Transfer Unit) is overfilled due to the input shaft seals leaking red automatic transmission fluid into the PTU (Power Transfer Unit). Replace the input shaft seals, refer to Input Shaft Seal .