shuttlefever Posted April 5, 2013 Share Posted April 5, 2013 My 79 n/a 2+2 5speed car needs a trans fluid change. Any recommendations for some slick stuff in an old trans?? Royal purple?? Synthetics good or not so much?? Always getting great info on here. Thanks in advance for the help!! Dennis~ Quote Link to comment Share on other sites More sharing options...
Chemicalblue Posted April 5, 2013 Share Posted April 5, 2013 Motul works very well. Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted April 5, 2013 Share Posted April 5, 2013 I'm using redline mt90. It's a bit harsh until it warms up. Quote Link to comment Share on other sites More sharing options...
FricFrac Posted April 5, 2013 Share Posted April 5, 2013 Redline MT90 is the go to for the Nissan tranny. The 350Z and 370Z use the MT85 - not sure if anyone has experimented with that in the early Nissan trannys.... Quote Link to comment Share on other sites More sharing options...
johnc Posted April 5, 2013 Share Posted April 5, 2013 MT90. Quote Link to comment Share on other sites More sharing options...
clarkspeed Posted April 5, 2013 Share Posted April 5, 2013 RL MT90 Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 5, 2013 Share Posted April 5, 2013 SWEPCO 201 or Ford Synthetic Manual Trans fluid. Quote Link to comment Share on other sites More sharing options...
shuttlefever Posted April 5, 2013 Author Share Posted April 5, 2013 Any opinions on Mobile 1 or Royal Purple? Quote Link to comment Share on other sites More sharing options...
NewZed Posted April 5, 2013 Share Posted April 5, 2013 Does yours need a change just because it's time or because it has shifting problems? Some of the newer "syncromesh" fluids are lower viscosity (~5W-30) than the older fluids. They're designed for today's transmissions. Quote Link to comment Share on other sites More sharing options...
shuttlefever Posted April 5, 2013 Author Share Posted April 5, 2013 Newzed, its both time and third gear is being a little cranky. I found some redline locally. Picking it up after work today. Thanks for the info!! As usual the HybridZ forums come through! Dennis~ Quote Link to comment Share on other sites More sharing options...
cpark_12 Posted April 27, 2013 Share Posted April 27, 2013 For those of you using redline...How long have you been running it? I've heard good and bad things about it. Quote Link to comment Share on other sites More sharing options...
darkstarrocker Posted April 27, 2013 Share Posted April 27, 2013 I like Honda's MTF. You'll only get around 30k miles before it starts to break down and get notchy though. You guys do know an 75w90 gear oil is very similar viscosity wise, to a 10w40 engine oil? The ad pack is the primary concern. Quote Link to comment Share on other sites More sharing options...
NewZed Posted April 27, 2013 Share Posted April 27, 2013 (edited) I like Honda's MTF. You'll only get around 30k miles before it starts to break down and get notchy though. You guys do know an 75w90 gear oil is very similar viscosity wise, to a 10w40 engine oil? The ad pack is the primary concern. I've seen it said that the gear oil numbers are different from the motor oil numbers, so they can't be compared. But I've never seen anything to support the statement, no test specs. or descriptions from evenan official looking source. I do know that 75W-90 gear oil pours much, much slower than 10W-40 motor oil at human (not engine) temperatures. Which seems to support that the same test and specs. apply to both. Who knows. I'd love to see a good professional source describing the different test methods for gear and motor oil. The link below seems to imply also that the same specs.are used. Otherwise, a 5W-30 gear oil would be like running 3 weight motor oil. Which doesn't seem likely, just considering bearings alone, let alone synchros. I'd love to learn more, I just haven't seen it yet. Ready for illumination. Edit - I've found a few more internet items suggesting that there are two specs for the two oils. But Amsoil is still labeling their gear oil as a 5W-30. So unless they decided to label their gear oil with a motor oil spec., there's precedence for the newer gear oils for modern cars, like Honda MTF, to be of lower viscosity. Hard to find a clear answer out there. http://www.amsoil.com/shop/by-product/transmission-fluid/manual/manual-synchromesh-transmission-fluid-5w-30/?zo=1368758&page=%2fstorefront%2fmtf.aspx Edited April 27, 2013 by NewZed Quote Link to comment Share on other sites More sharing options...
johnc Posted April 29, 2013 Share Posted April 29, 2013 You do not want want "super slick" gear oil in any of the Datsun/Nissan RWD transmissions. Redline MT90 is specific for transmissions running brass synchros. I know Jon recommends Swepco 201 but I wasted a Datsun 4 speed in one race after changing to 201. My trans guy at the time (Bill Breedlove) said the synchro were too slippery from the Swepco. I've run MT90 or a 50/50 mix of straight 30w non-detergent engine oil and ATF from then on without a problem. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 29, 2013 Share Posted April 29, 2013 I've converted quite a few people to SWEPCO (even a few here) and I did work at a Porsche shop where we used it on every car that rolled through the door, brass synchro, steel synchro, etc. None of them had problems with the lube being too slippery but quite a few have said that it worked better than Redline. In fact I don't think a single person who has tried both has come back and said they preferred Redline to SWEPCO. Between myself, the customers from that shop, and people I've converted, you've got to be talking about millions of miles on it. FWIW my boss at the Porsche shop converted me from running 40 weight motor oil. I never cut the motor oil with ATF (although I did that with the SWEPCO), but he said motor oil didn't have enough lubricity under pressure. He wasn't a chemist, he was a mechanic with lots of racing experience, so take that for what it is worth. I switched, had much smoother shifting afterwards, and never looked back. Really though, I think ANY good quality oil will do fine. Is SWEPCO better than Redline? IMO, yes, but it's not like one is crap and the other is fantastic. They're both very good. The FoMoCo stuff is basically indistinguishable in my Miata trans from the SWEPCO, and it's in stock at your local dealer. I would guess that Amsoil, Royal Purple, et al are also just fine. Quote Link to comment Share on other sites More sharing options...
duragg Posted April 29, 2013 Share Posted April 29, 2013 I went through a long tranny learning process and tried about 5 different juices from plane-old dime store GL to Mt90 and GMFMSM and some others. Frankly I am not sure the dime-store GL wasn't just as good or better than any of them. I did settle on MT90 primarily becauase it was easily identifiable in case of leaks (red) smells better and is easy to fill and drain. I never found the Swepco locally or easily so that one never happened for me. TJ Quote Link to comment Share on other sites More sharing options...
NewZed Posted April 29, 2013 Share Posted April 29, 2013 Perception probably depends on whether the user is looking for smooth notch-free shifting in the cold or grind-free shifting at 7000 RPM. I've seen long discussions about getting rid of notchiness when it's cold out. A racer who changes fluids after every event or season won't have the same view of quality as a daily driver from Minnesota who will probably leave the fluid in for 30,000 miles. Redline has a paper on how their fluid is engineered with the proper coefficient of friction under high shear rates to allow the synchros to work correctly (see the MTL and MT90 Tech Info paper from the link below). The chart on page two is interesting because it shows viscosities at 100 degrees C. 10W-30 motor oil apparently has a higher viscosity than 80W gear oil at use temperature. So there must be different test standards for labeling the fluids (as impled by darkstar, and answers part of my question from above). The chart also shows that viscosity breaks down pretty quickly for the motor oil and ATF. Something to consider. http://www.redlineoil.com/techinfo.aspx I'm one of the Swepco 201 converts, but at 75/25 with ATF. Worked better than MT90 in an old, probably rusty inside, 1983 5 speed for high RPM 1-2 and 2-3 shifts. But it is a little notchy when cold out. No yellow flakes (I checked) or signs of excess wear after ~15,000 mlies. Prior to that I chose MT90 over Valvoline 75W-90 in a 1978 5 speed for better high RPM 2-3 shifting. Both transmissions high mileage, which could be a factor. One more anecdote... letitsnow used the super-duper Pennzoil Synchromesh and seemed to like it. He's shifting at high RPM. Post #120 in duragg's thread - http://forums.hybridz.org/topic/110792-high-rpm-shifting-dynamics/page-6 Quote Link to comment Share on other sites More sharing options...
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