icanfixall
Official GMM hand model
I have around 200,000 miles on my gear oil and want to upgrade to syntheic oil. Which oil would be recommended here...
Not a daily driver but I do haul heavy and fast sometimes. The Accord gets 30 mpg and the truck gets 19 mpg. The Honda is cheaper to drive but not a fun driver being so close to the ground and semi tires.
Every time I have tried to use an synthetics on any vehicle with mileage on it I sprout leaks. I have given up on synthetics all together due to there costs, with no real advantages, and the fact that anything I put it in develops a leak.
For diffs , trannys , and transfer cases, I recommend the same thing as for engines. Before doing the switch, run a treatment of Auto RX. It will revive the old seals and prepare them to where they won't gush the synthetic out all over the place . For diffs, you put 2 oz of the stuff in per qt of oil and run it for 1000 miles, then drain it and do the change. That stuff is VERY effective. if it doesn't do the job, your seals were on their way out anyway.
dang, 30 for a bottle of gear oil?? Too bad I can't get one of those oil filters for my truck thoughOn the contrary, I have converted many vehicles to synthetic with no leak issues. My truck had 136,000 on it when I got it and I immediately switched everything but the engine to synthetic. I run Royal Purple in mine cause it's readily available. Have no problem with Amsoil either, sold it and ran it for years, but no one around here seems to stock it, and if they do, it's double everything else.
dang, 30 for a bottle of gear oil?? Too bad I can't get one of those oil filters for my truck though
My thinking about changing the gear oil to synthetic is too gain some mileage. I get between 18 to just short of 20 mpg running 75 to 85 mph and in double overdrive at 1700 rpm... I know I could get better miles per gallon if I slowed down but... Thats just not fun...