Now I’m about to drain the oil and refill it, but I’m still not sure if I used the right oil. Could the choice of transmission lubricant make a difference in gear noise? Not sure if the noise is coming from the transmission or the differential. The noise comes back again as the engine breaks during a deceleration. Once I let off the accelerator pedal, the noise goes away. With the top up driving around 60 to 70 mph, OD engaged, I’m hearing a fairly high pitched noise while accelerating. Filled it with SAE 30 non-detergent oil and ran it on the road for about 1000 miles. Last year, I rebuilt an early 1970’s TR6 transmission with a J-type overdrive. SAE 30 non-detergent, SAE 30 detergent, 20W50 (with zinc), EP80/90l GL4 synthetic or not?
Which lubricant to use in a TR6 J-type overdrive transmission?
