Re: BORG WARNER OVERDRIVE PARTS SOURCE

Posted by HH56 On 2017/1/10 11:33:02

IIRC, one R9 failure was the smaller R9 pinion planetary and over running clutch was found to have been installed inside the OD of a car with a large engine. That unit should have had the 4 pinion heavy duty R9-A1 setup but the smaller 3 pinion unit will fit inside the larger case. Not knowing better, I was guilty of doing one of those misguided repairs myself. From the color of the OD unit that was evident in the photo that was posted it may even have been the one I did some 35 years ago. IIRC the failure was due to a lot of wear on the overrunning clutch ramp and roller surface of the smaller unit and it would no longer lock so no forward motion.

Another units failure reason was not proven conclusively but surmised that the lube had not been changed in a considerable time. Lube was found to be thick and congealed -- possibly even low. Kirtie did a very nice writeup with photos of that rebuild over at the PAC project forum.

The other unit I don't recall if it was mentioned whether there had been an actual driving failure. It may have been a routine inspection during an engine and trans overhaul but OD was found to have excessive wear in the pinion shafts resulting in loose pinions and for sure an eventual failure.

At least you know your lube has been changed. Checking and keeping it at the proper level should go a long way toward prolonging the life of the OD.