Keep Those Trannys Rolling - October/November - 2021

To Infinity & Beyond, The Leak That Won’t Quit!

In this issue of Keep Those Trannys Rolling, we’ll take a look at a 2014 Infinity QX60 with a RE0F10E CVT transmission experiencing a never-ending transfer assembly leak.

This vehicle had been taken to several automotive shops to repair the leak. According to the local dealership, the replacement cost of the transfer assembly would be approximately $4,000.00. To save you time, I will walk you through the process needed to repair this transfer assembly leak.

Initial Inspection and Test Drive:

As usual, you don’t want to take anything for granted. Always perform an under-hood inspection to verify everything is okay. You should also inspect the underside of the vehicle and verify what is leaking. If there is evidence of oil leaking from the transfer seal area, you should clean the area around the transfer assembly and then re-inspect it after your initial test drive.

During the test drive, you should drive the vehicle through city streets and then onto the highway. Verify that the vehicle is operating properly. You should drive the vehicle through a couple of sandy areas to make sure the AWD system is working properly and then head back to the shop and inspect the transfer assembly area for leaks.

Back at the Shop:

Inspect the underside of the vehicle to see if the transfer assembly right-side axle seal is leaking. If there are signs of oil leaking, DO NOT replace the axle seal. In our case, the seal was new (figure one). Next, check the CV joints. They should move freely, and the boots should be tight, without any leakage. Check the axle seal surface area for nicks or rust. Check the axle for excess run-out. To familiarize yourself with the internal components of the transfer assembly, you should access your technical database to obtain a break-down illustration of the transfer assembly. Here’s why, according to the illustration, the transfer assembly has a right inner seal and o-ring (figure two). That means, unless you take the side cover off to inspect the inner seal, you won’t know if it’s good or bad. Since the outer seal had already been replaced and was still leaking, it was time to order a transfer assembly reseal kit and prepare to remove the transfer assembly from the vehicle.

Transfer Assembly RDI (remove/disassemble/ inspect):

To remove the transfer assembly, you must remove the front axles, the right exhaust manifold, and the six (6) bolts attaching the transfer assembly to the transmission. Then remove the transfer assembly from the side of the transmission. Once the transfer assembly is on the bench, remove the right-side transfer assembly cover to inspect the driveshaft inner oil seal and o-ring. In this case, the drive shaft inner o-ring was flattened and had signs of oil bypassing the o-ring (figure three).

Transfer Reassembly and Install:

The repair is pretty simple from here, install the new driveshaft inner oil seal, o-ring, and axle shaft outer seal into the right-side transfer cover. Then install the right-side transfer cover onto the transfer assembly and fill the transfer assembly with 5/8 of a pint of Nissan Differential Hypoid Super GL-5 80W-90W oil. Install the transfer assembly back onto the transmission, install the axles, and the right exhaust manifold. After the transfer assembly installation is complete, start the vehicle and allow it to warm up to normal operating temperature. With the wheels off the ground, run the vehicle through several shift sequences and then reinspect the right axle for leaks. If no leaks are found, lower the vehicle to the ground and head out for your final test drive.

Final Test Drive and Inspection:

Test-drive the vehicle again, through city streets, and then onto the highway. Drive the vehicle through a couple of sandy areas just to make sure the AWD system is still working properly. Head back to the shop for your final inspection. Re-inspect the transfer assembly for leaks. If there are no leaks from the right axle seal area, recheck the transfer assembly and transmission fluid levels and verify that they are full.

Well, there you have it. With this information, you should be able to replace the drive shaft inner seal and o-ring and save the customer an expensive $4,000.00 transfer assembly replacement. With a little insight and the customer’s best interest in mind, you should have no problem “keeping those trannys rolling” to infinity and beyond.