Posted March 2, 201510 yr comment_464741 I'm close to finishing the auto to manual tranny conversion on my 71 240Z. It's a 5 speed out of a 78 280Z. Since I bought the transmission at a junk yard with no way of knowing it's condition, I took it to a reputable transmission shop to get it looked at before I put it in. They replaced one bearing and said everything else is good. So, do I fill it with whatever is originally recommened, or have any of you had better luck with anything else. I live in Iowa, so it only gets driven in warm weather and put away in the winter. Thanks. Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/ Share on other sites More sharing options...
March 2, 201510 yr comment_464750 True GL4 oil. Not GL5. Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464750 Share on other sites More sharing options...
March 2, 201510 yr comment_464751 The Datsun transmissions seem to do very well with Redline's MT-90 oil. Better than a generic 90 wt., for sure, with a transmission that has some miles on it. Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464751 Share on other sites More sharing options...
March 2, 201510 yr comment_464754 Pennzoil Synchromesh. You need an oil that works with yellow metals such as Datsun's brass syncros. Redline works too. Chuck Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464754 Share on other sites More sharing options...
March 2, 201510 yr comment_464756 Pennzoil Synchromesh. You need an oil that works with yellow metals such as Datsun's brass syncros. Redline works too. Chuck I have also used both of these. Redline currently. I have developed a leak between the engine and gearbox.Not too bad. I think it is the gearbox. If so I don't think any issue with the oil. My seal is the origional from 1978.If you do still have your gearbox out I would change the seals anyway. Edited March 2, 201510 yr by lumens Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464756 Share on other sites More sharing options...
March 2, 201510 yr comment_464758 Yep Redline GL4 75-90. What I have always used. Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464758 Share on other sites More sharing options...
March 3, 201510 yr comment_464767 I have Redline MT-90 in my 5 speed. Penzoil Synchromesh is the only other oil that I know of that is a GL4. Don't use anything else or it will eat your syncros.(There is sulfur in the GL5 oils and it destroys the bronze synchronizer gears in the transmission.) Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464767 Share on other sites More sharing options...
March 3, 201510 yr Author comment_464770 Thanks for all the great advice! I think I'll go with redline. Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464770 Share on other sites More sharing options...
March 3, 201510 yr comment_464775 It's the NS you need to look for as in Redline 75w/90 NS (no sulfur) Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464775 Share on other sites More sharing options...
March 3, 201510 yr comment_464778 Redline MT-90 or Brad-Penn Multi-purpose Classic. Both are GL-4. Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464778 Share on other sites More sharing options...
March 3, 201510 yr comment_464782 It's the NS you need to look for as in Redline 75w/90 NS (no sulfur) FYI, in Redline-speak NS means "No Slip", i.e. no added friction modifiers (typically used for clutch limited slips). It has nothing to do with sulfur content. Furthermore, the NS stuff is GL-5, not the GL-4 that Z-car transmissions call for. Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464782 Share on other sites More sharing options...
March 3, 201510 yr comment_464797 Thanks Leon, I gotta stop taking forum opinions as facts. I think I'll just go out and drain my tranny right now. Link to comment https://www.classiczcars.com/forums/topic/51042-manual-transmission-oil-whats-best/#findComment-464797 Share on other sites More sharing options...
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