smalafy 1 #1 Posted August 29, 2021 I have a 1986 414-8 and had to change the oil in the unidrive and I was wondering what weight gear oil am I supposed to use ? 1 Share this post Link to post Share on other sites
stevasaurus 22,859 #2 Posted August 29, 2021 You want to use 90 wt if you can find it. About 2 qts. 80/90 wt is fine also. Tractor Supply, and most auto stores will have it. Welcome to Red Square. 3 Share this post Link to post Share on other sites
Snoopy11 5,714 #3 Posted August 30, 2021 1 hour ago, stevasaurus said: You want to use 90 wt if you can find it. About 2 qts. 80/90 wt is fine also. Tractor Supply, and most auto stores will have it. Welcome to Red Square. +1, dat's what I use. Works very well. Lucas oil is the best, in my opinion... just pricey... Don 1 Share this post Link to post Share on other sites
smalafy 1 #4 Posted August 30, 2021 Thanks, I was thinking that but just wanted to make sure. Share this post Link to post Share on other sites
71_Bronco 1,072 #6 Posted August 30, 2021 If I recall correctly, I jus used the blue bottle from Walmart. They had 1 gallon jugs of the 80W-90 last time I bought it. Brand is "Super Tech". Probably not the best stuff out there, but then again, these are not really top-fuel dragsters here we are dealing with. 1 Share this post Link to post Share on other sites
peter lena 8,720 #7 Posted August 30, 2021 @71_Bronco agree with you on the oil , make a point of dropping my trans oil , every other year , unless something shows' it self. make a point of checking it regularly , and related linkage points . pete Share this post Link to post Share on other sites
smalafy 1 #8 Posted August 30, 2021 I agree with you and bought 2 quarts of Rural Kings 80-90 gear oil. I do not see the need for expensive synthetics in the gear box as it is not pulling heavy loads. Share this post Link to post Share on other sites
