Transmission Oil


Date: Mon, 3 May 1999

My "Big Boy Toy" is a '67 P1800, 4-speed with overdrive. According to the shop manual, the trany is supposed to use non-detergent 30-weight oil. This day and age, that item is getting harder and harder to find. Is there any reason not to use standard gear lube, say 75-90 weight? Is it too heavy for the overdrive solenoid? The rear output shaft has worn just enough that even new rear trany seals tend to leak a bit. I thought maybe the heavier lube may help curb some of the drip. Any advice will be helpful. Thanks.

Frank Jackson

Dentedtuba@aol.com


Frank - Your suspicions are right. Standard gear lube is too heavy for the overdrive, and can cause problems. Also, modern gear oil is too slick for the synchronizers in the old Volvo tranmissions, and will cause grinding gear shifts. I don't think it would help the leak much, either. If you can't find non-detergent 30W oil, I'd try detergent 30W before I tried gear oil. -Glenn.


Return to Power Train.

Return to Letters.

Return to front page.