Agip trans oil vs. Mobil 1

I just had Agip LSX transmission oil installed during service replacing the Mobil 1. I had purchased, but not installed Red Line NS, but the shop recommended Agip so I tried it. The rationale for Agip was that it is fully synthetic, recommended by the factory, and it helps the second gear issue. The results are that it shifts very much better than Mobil 1 in all gears and especially the shift into second. Chatter is also reduced with the Agip. The Mobil 1 had about 6K miles on it, so I don't know if part of the difference was just new oil versus old. It doesn't completely solve second gear, I need to hesitate briefly into 2nd when cold and it is possible to beat the synchros with really fast shifts when warm, but overall, I am very happy with the shifting. I'll stick with it because it is factory recommended and I don't need to worry about additives or whether yellow metals are melting. My guess (and it is a complete guess) is that Red Line NS is probably better for 2nd gear. The Agip LSX has limited slip additives like the non-NS Red Line, but Agip also makes a SXA version that is like NS -- it probably is also better than LSX for second gear and maybe worse for limited slip chatter. In truth, I don't know how advantageous "factory recommended" is becasue the owner's manual calls for Agip Rotra MP SAE 80W90 -- which presumably is not the same as Agip LSX -- but for whatever reason I feel comfortable with Agip.

 

Mike,

My car has 36k miles. I don't think the think the synchros are worn, but I think it is just the 2nd gear reluctance that this gearbox is known for. With Mobil 1, second gear was lousy when cold and 90% when warm -- meaning that it could crunch unless it was delicately shifted into second. I didn't have any crunch issues in 3rd, but the upper gear shifting was not as smooth as it is now. Second gear is now 99% good. My brother just drove the car a thought the transmission was perfect and he has a more objective view since I am hyper-focused on 2nd post oil change. What trans oil are you currently using? The oil makes a huge difference because the synchros rely on friction to work; therefore, the wrong oil can render even good synchos ineffective and the right oil can make slightly worn synchros work better. I suspect there is a very good chance that Red Line NS or Agip SXA will help, possibly to the point of not needing to change the synchros. There was some concern that Red Line NS required a small amount of additives for limited slip chatter that is bad for the "yellow" metals, but I don't think it was definitively answered whether the transmission actually has any yellow metal. Also, several are running NS without the additives. I decided to sit on the sidelines with Agip until the dust settles on the Red Line discussion, but I feel comfortable enough with Agip that I probably won't install the Red Line I have sitting on my shelf bcause of the "factory recommended" thing -- but I'm not sure how either Agip LSX or SXA compare to the factory recommended Agip MP oil. If SXA is just as recommended as LSX, that is probably a better choice for the synchros and maybe not as good for the limited slip.

 

Mike,

One other item I haven't seen mentioned in the transmission discussions is that the F-car tranny seems particularly sensitive to the clutch being fully depressed when shifting. In every other car I've driven I usually start to shift before the cluth is fully depressed -- I think most people do this without realizing it. In the F-car only, fully depressing the clutch before shifting seems to work much better. I still don't wait for the clutch to hit the stops before shifting, but I do delay the shift to be deeper in the clutch pedal movement than with other cars. You may want to try expiriment with this to see if it helps your 2nd and 3rd issues.