sorry, my fault for a poor description. what i meant was that at 60k it only calls for inspection (as opposed to replacement). it also calls for inspection every 15k, but i dont see that it ever actually calls for replacement (i.e. inspect at 15k, 30k, 45k, but replace at 60k)...

 

how often should we do this?

 

@goredcar How's the GM friction modified been working? Any noticeable changes in feeling, gas mileage, performance, etc??? This question might sound stupid but does anyone know the recommended shifting RPM point? I usually shift around 3k. After my MTF with OEM fluid, it's been better but the "notchy" feeling is still there, just not as bad as before. A buddy of mines mentioned to maybe change the slave clutch cylinder. He thinks it's not allowing the the clutch to engage properly.... If I double clutch, I get 0 notchiness 100% of the time.... any thoughts?

 

recommended shifting point? Is this your first manual car?

 

negative, i've had multiple manual vehicles, but this is my first RWD. just feel that its slightly smoother when shifting under 3k thats all.

 

Just did this with Redline MT-85 75w85. Did rear diff with Mobil 1 75w90. Thanks for the writeups...easy peasy. I did manage to leave the drain pan under the car when I drove away lol...otherwise all good.

 

were you having the notchy feeling issues prior to the mt-85 change? if so, did it eliminate it or help at all?

 

I did my first MT flush along with all the other maintenance items listed in the premium section of the maintenance guide at 30k miles. Followed BB's DIY for this and the LSD. I used the same AMSOIL product as BB for the transmission, but tried MOTUL Gear 300 75W90 for the LSD. Car ran great up to 73k miles. I did not have any notchy shifting (I live in San Diego). My plan was to flush the fluids again at 60k miles. I know it was probably overkill, but I'm hard on my G and San Diego gets really hot, so i try to put in the extra effort to keep her up. Due to my work schedule I did not get a chance to flush the transmission and LSD until I hit 73k miles.

So I have 73k miles on the G now and I went to do the transmission flush and LSD flush. Just like iGoya585's post with pics, I did the flush in my garage on jack stands (had the car about as level as I could get it). This time around I was planning to use MOTUL Gear 300 LS oil, 75W90 for both flushes as I heard it is good for high temps and I know my transmission gets crazy hot as I can feel the heat coming up from the floorboards and center counsel. I conducted the flush following the DIY just the same as last time and then put the G back on the ground to fire her up and drive it around to test my work. That's when I noticed the shifter was very notchy getting into all gears, except 3rd and 4th, which it simple would not go into at all! I turned the G off and tried shifting gears and it felt the exact same. I turned the G back on, put it in 1st, and went to drive forward slowly. As I came off the clutch the car started shaking and jerking around. I quickly engaged the clutch and put in neutral. Car did the same thing in reverse. I went back through the steps to make sure I didn't make any mistakes conducting the flush and I did everything exact to the DIY and as I did last time with no issues. I lifted the G again and opened the fill plug, then put the G on the ground to drain out any excess fluid in case I overfilled it because it wasn't completely leveled when jacked up. Only about 1 oz of fluid came out. And the car still ran the same way. Not sure what is going on now...

The only thing I can possibly think of and I will be checking into this once I get more fluid is that I ordered new drain plugs and gaskets from Z1 Motorsports. I got the ones labeled for the MT, but the drain plug looks just like the one for the LSD (has a magnet and is about 1/2" longer than the normal MT drain plug). I installed that plug, but now I'm worried that maybe that extra length for the magnet is hitting gears.

The only other thing I can think of was that I had a lightweight clutch and flywheel installed about 6k miles ago and I have a hunch that the shop batched the install as I still get bad clutch burn and after that install it got hard to put the car in 1st and reverse. I'm going to flush the clutch fluid and take apart my aftermarket shifter to see if that helps.

Any advice on possible issues is appreciated!

 

The spec for the MT is to use a GL-4 fluid, not gl-5. GL5 reacts harshly with the brass syncros. This may be part of your shifting issue, though I doubt the effects would be apparent immediately.

Once in gear, the above shouldn't matter. Doesn't explain the jerking/shaking. Is your idle smooth? You absolutely sure you didn't upset anything else during this process?

Sounds like several issues are present, including a misalignment of the shifter gate plate.

Make absolutely sure you order the right spec and weight fluid - gl4 for the trans, gl5 for the rear end.

Good read: http://www.widman.biz/uploads/Transaxle_oil.pdf

Proper fluid for our cars ---- http://www.redlineoil.com/product.aspx?pid=140&pcid=7

 

I didn't have any notchy issues prior to the change, but haven't noticed any with the MT-85 either. Only have about 400 miles with it in there so far.

 

It's been about 20 months and 8100 miles (~15K on the odometer) since I change the MT oil to redline mt 85. No issues last winter. This winter when the temps got cold (<32F), 2nd gear became very difficult to engage. For smoothest shifts, I go from 1st to 3rd, double clutch then back to 2nd. This is only needed until the gearbox warms up then 2nd gear is fine.

All gears in general feel slightly notchier than I remember. The car is not beat on or tracked, just normal driving. Can't imagine 8K being much on a trans oil. Debating switching back to stock, another round of MT85, or something else..

Thoughts?

 

So we have beautiful weather and I had some time to work on the cars this weekend so I did another fluid change. This time I went with a cocktail suggested by Ryan of RJM Performance (the clutch pedal guy). On another forum quite a while back he maentioned that he'd tried multiple fluids and combinations of fluids and gave his thoughts on how they ranked. The one he liked best is 1 part Amsoil Synchromesh manual transmission oil to 2 parts Redline MT85. I went with it. In 2 relatively short test drives, it seems great. It's not currently cold here, but the benefit of this mixture is smoother shifting in both cold weather and at high temperatures. In both cars it seems to be very smooth. I'll update when I've had a chance to put several hundred miles on it in different driving conditions. But so far, I can say I like it.

 

I should update my experience since going back to nissan MT. Cold shifts have improved. They're not perfect, but easier to get it into 2nd than before. I don't recall for sure, but I think with MT85 it was better yet in the cold. Still can't imagine this fluid breaking down so quickly (10K miles), or having its cold temp characteristics altered significantly.

I may try BB's suggestion in the previous post next time around.

@BB, is this the 5w30 product? AMSOIL Manual Synchromesh Transmission Fluid 5W-30

Consider yourself lucky, we're buried at nearly a foot of snow, with another 6+ inches promised today.

 

That's the exact one.

Beautifully sunny and 73 here today.

 

Also I somehow ended up with 2 unopened quarts of Redline MT85 and about a half quart of Redline 75W90 GL5. If anybody wants them, shoot me an offer becasue I probably won't need them for a long time. No need to sit on my shelf if someone else is going to buy some anyway.