Power Transfer Unit Fluid Leak Diagnosis

FLUID LEAK DIAGNOSIS

When diagnosing fluid leaks on the Power Transfer Unit two weep holes are provided to diagnose certain seal leaks. These holes are located on the bottom side of the assembly (Figure 1).





Figure 1 Weep Hole Locations







If fluid leak is detected from either weep hole, seal replacement is necessary. Do not attempt to repair the leak by sealing weep holes, they must be kept clear of sealants for proper seal operation.


If fluid is leaking from weep hole A (Figure 1) the type of fluid leaking will determine which seal needs to be replaced. If the fluid leaking is red in color (transmission fluid) this indicates that the Transmission differential carrier seal should be replaced. If the fluid leaking is light brown (gear lube) this indicates that the Power Transfer Unit input seal should be replaced. For replacement of these seals refer to Power Transfer Unit.


If fluid is leaking from weep hole B (Figure 1) the type of fluid leaking will determine which seal is leaking. If the fluid leaking is red in color (transmission fluid) this indicates that the input shaft end seal should be replaced. If the fluid leaking is light brown (gear lube) this indicates that the half shaft inner seal and P.T.U. input shaft cover seal should be replaced. For replacement of these seals refer to Power Transfer Unit.


Before condemning any seal or gasket be sure that the rear rocker arm cover on the engine is not the cause of the oil leak. Oil leaking from the rocker arm cover is easily mistaken for a leaking Power Transfer Unit.