Change your manual transmission fluid ASAP!!!

[JS + BRZ]

Nevermind. Found the answer.

Roughly 2.6 for the tranny and 1.25 for the diff

[roddy]

Originally Posted by Sellout

Not according to the people who make it.

Thanks for pointing that out. It must have been a recent change...the quarts I bought last summer all say 70W80 on the bottle.

[Vracer111]

Swapped out my transmission fluid at a little over 1k miles and now a little past 19k miles. Redline MT-85 seems to be holding up fine no issue with shifts and never had any gear issues whatsoever with the car, plug hardly had anything on it when it was changed. Differential changed at the same time as well, plug was really goopey and lot of small metallic flakes. Changed rear end fluid to Redline 75W85.

[kayoh]

Originally Posted by Vracer111

Swapped out my transmission fluid at a little over 1k miles and now a little past 19k miles. Redline MT-85 seems to be holding up fine no issue with shifts and never had any gear issues whatsoever with the car, plug hardly had anything on it when it was changed. Differential changed at the same time as well, plug was really goopey and lot of small metallic flakes. Changed rear end fluid to Redline 75W85.

What color was your stock transmission fluid when you changed it?

[Vracer111]

Originally Posted by kayoh

What color was your stock transmission fluid when you changed it?

Basically a little darker than new fluid...still pretty fresh looking.

[Carban]

@Vracer111 I changed my transmission fluid today with Red Line MT-85 75w85 also. Im curious if you used the same Red Line 75w-85 for your differential?

Our rear diff's call for gl-5 fluid whereas the red line mt-85 is gl-4. (The red line mt-85 bottle also says "not suited for gl-5 required differentials")

Just wanted to give you a heads up in case you used gl-4 in ur diff.

[Vracer111]

Originally Posted by Carban

@Vracer111 I changed my transmission fluid today with Red Line MT-85 75w85 also. Im curious if you used the same Red Line 75w-85 for your differential?

Our rear diff's call for gl-5 fluid whereas the red line mt-85 is gl-4. (The red line mt-85 bottle also says "not suited for gl-5 required differentials")

Just wanted to give you a heads up in case you used gl-4 in ur diff.

No, Redline MT-85 for transmission and Redline 75W85 gear oil for differential...

[wheelhaus]

Originally Posted by Sellout

That happens intentionally. The box locks you out until the synchro has had time to speed up the input shaft and clutch disk when you're downshifting. Hold it there and you can hear things speed up, then it will drop into first...

That's the same mechanism that locks us out of second when the transmission is cold.

I want to clarify this as it's a bit misleading... The gearbox does not have any special mechanism that locks you out of any gears, anytime, ever, it doesn't exist. The effect of the thick cold fluid however, prevents the synchros from generating the necessary friction to do their job effectively. This results in what feels like a lockout, but it's just the synchros unable to do their job.

Upshifting quickly and relatively firmly helps to ensure you catch the next gear as the revs drop. The thick cold fluid will slow the transmission internals down much quicker than normal when you clutch in. Downshifting is much more difficult as the synchros need to speed up the tranny. Double clutching is the best way to get the cold tranny to cooperate.

If you slow shift and the tranny internal RPM drops too far, it'll feel "locked out". Engage the clutch in neutral and blip the throttle a bit higher than it needs to be for the gear you want, and then quickly clutch-in and shift into it; should drop right in. (This is the essence of double clutching, as it bypasses the synchro's friction function and instead uses the engine to speed up the transmission internals before engaging a gear).

[Sellout]

Originally Posted by wheelhaus

I want to clarify this as it's a bit misleading... The gearbox does not have any special mechanism that locks you out of any gears, anytime, ever, it doesn't exist. The effect of the thick cold fluid however, prevents the synchros from generating the necessary friction to do their job effectively. This results in what feels like a lockout, but it's just the synchros unable to do their job.

Upshifting quickly and relatively firmly helps to ensure you catch the next gear as the revs drop. The thick cold fluid will slow the transmission internals down much quicker than normal when you clutch in. Downshifting is much more difficult as the synchros need to speed up the tranny. Double clutching is the best way to get the cold tranny to cooperate.

If you slow shift and the tranny internal RPM drops too far, it'll feel "locked out". Engage the clutch in neutral and blip the throttle a bit higher than it needs to be for the gear you want, and then quickly clutch-in and shift into it; should drop right in. (This is the essence of double clutching, as it bypasses the synchro's friction function and instead uses the engine to speed up the transmission internals before engaging a gear).

The whole idea of the synchronizer system is to delay the system from sliding the locking ring down onto the gear you're selecting until everything is lined up. When the synchro system is working correctly it stops you from selecting a gear until the synchro and locking ring line up. The teeth on the synchro and locking ring are stuck pushing against each other on the ramp faces instead of sliding down next to each other and engaging that locking ring. That's what you feel when you're locked out of gear.

The gear stack is turning because you're moving. The input shaft may slow down after the clutch is disengaged, and at that point the synchros are doing what they would be doing on a downshift, they're not suddenly obsolete because the input shaft slowed down a little faster than normal.

What I said was quick and dirty, but misleading? I think that's a stretch.

[wheelhaus]

Originally Posted by Sellout

The whole idea of the synchronizer system is to delay the system from sliding the locking ring down onto the gear you're selecting until everything is lined up. When the synchro system is working correctly it stops you from selecting a gear until the synchro and locking ring line up. The teeth on the synchro and locking ring are stuck pushing against each other on the ramp faces instead of sliding down next to each other and engaging that locking ring. That's what you feel when you're locked out of gear.

The gear stack is turning because you're moving. The input shaft may slow down after the clutch is disengaged, and at that point the synchros are doing what they would be doing on a downshift, they're not suddenly obsolete because the input shaft slowed down a little faster than normal.

What I said was quick and dirty, but misleading? I think that's a stretch.

Sounds like we're just arguing semantics. Didn't mean any offense, I just wasn't sure if you were using the word "mechanism" to literally mean an additional device inside the gearbox, or a descriptor of how the synchros operate.

[xxBrun0xx]

Read through this entire thread and still not sure when the general consensus is to change your trany fluid?

I've got 800 miles on my 14 brz and have seen a lot of you guys change at 1k. Manual says (I believe) 30k before the first change.

I know stock engine oil is specifically designed to help break in the engine, and therefore changing it early will do more harm than good. Is it possible the stock tranny/diff fluids are meant to help break in the tranny/diff as well?

Also, does anyone know what other cars have the same trannies as our 86's? If we could find cars that have been around longer with the same tranny, we might be able to find more information about what long-term effects different fluids will have on ours.

[edsbreezy]

Originally Posted by xxBrun0xx

Read through this entire thread and still not sure when the general consensus is to change your trany fluid?

I've got 800 miles on my 14 brz and have seen a lot of you guys change at 1k. Manual says (I believe) 30k before the first change.

I know stock engine oil is specifically designed to help break in the engine, and therefore changing it early will do more harm than good. Is it possible the stock tranny/diff fluids are meant to help break in the tranny/diff as well?

Also, does anyone know what other cars have the same trannies as our 86's? If we could find cars that have been around longer with the same tranny, we might be able to find more information about what long-term effects different fluids will have on ours.

I'd like to know as well, I just changed my oil at 1500 miles on my 2014 today and did it since i've always changed it on or at around 1000 miles on my last 3 new cars. i've been reading through a lot of threads and am curious to know what the general concensus is on changing transmission and differential fluids. i'm looking at getting a short shifter, bushing, and mtec springs and figured i would change the fluid then.

[xxBrun0xx]

Found this with regards to what fluid we should be using:
http://www.ft86club.com/forums/showthread.php?t=16604

Cliff notes, since I read the whole thing: Use Pentosin mtl 75-80 for your transmission, Motul Gear 300 GL4/GL5 75W90* for your rear diff. Alternatively, apparently Nissan dealerships stock stuff that is 100% identical to pentosin for a fraction of the price, although I haven't taken a trip my local dealer ship to get a part number for that yet.

Sent from my XT1053 using Tapatalk

[krulux]

Unless you are having real shifting trouble - i.e. grinding noise/feel between shifts then more than likely you are safe to wait until the first scheduled tranny/pumpkin fluid inspection.. which is 30K I believe.

That said, there is nothing wrong with being proactive and replacing with a quality solution as many here suggest.

Me personally, as I ramp up to a forced induction application.. and the prospect of upgrading the clutch comes into play - I'll be changing the fluid in my car at that time