Rear Diff Gear Oil Change Interval

[Shinsen774]

Seems like the traffic on the site is a little light so I figured I'd ask a few simple questions I have to get y'all's opinions (I am from North Carolina so I can use the double contraction y'all's). I am an LBC novice and certainly no mechanic and appreciate your insight.

I have a '64 MGB, banjo rear diff with about 157,000 miles and was restored twenty or more years ago. I changed the diff gear oil (90w) last January. I am driving about only 1200 to 1500 miles a year. Car runs great. How often should I change the rear diff oil under these conditions (miles and/or months)?

Same question for the transmission oil (3 syncho). I used Castrol 20w50 about a year and 1200 to 1500 miles ago. Tranny shifts smoothly, no problems, oil level remains constant and looks clean on the dipstick.

Thanks for you thoughts.

 

[PAUL161]

Not trying to sound strange but, if you changed the oil in the rear last year, you probably won't have to do it again for another 5 years or so. As long as there is no metal particles in the rear, the oil, (90wt), will last for years.
As for the transmission, if it looks clean and everything is working proper, maybe every 30 to 50,000 miles. If the dipstick shows water droplets or foam, say from condensation during storage, then I wouldn't hesitate to change it. That's just my personal opinion. PJ

 

[Steve_S]

Simply follow the manufacturer's recommended service schedule as found in the owner's manual.