Just received my 1st bottle of the good stuff Auto-RX.
2002 Jetta Automatic TDI (diesel) 1.9L, 135K miles with a very slow leak at the differential where the axles assemble to the tranny. The differential is separate from the transmission fluid - two different fluids.
The leak is a problem because it drips on the dog-bone mount/ support and damages the rubber parts. To replace the seals is a job
Question do I add ARX (2oz/ Liter) to the current synthetic (Fucsh Titan Sintopoid) GL5 75W90 gear oil (normally use), or do I add it to a conventional mineral based GL5 75W90 oil (2oz/Liter). The ARX instructions on the differential do not mention conventional oil - I've picked up some Valvoline conventional 75W90 at Autozone. Looking at the instructions for fixing a leak possible I add ARX to the synthetic for 1000 miles then do a rinse step with the Valvoline conventional.
In the past when I changed the differential fluid it comes out very dirty. I purchased the car at 120K miles - most likely not maintained well. Possibly the seals just need a good cleaning. Any words of advice is appreciated.