Redline MTL vs Amsoil MTG

[aquariuscsm]

I think I`ve narrowed my manual transmission fill between these two. Alot of people on here recommend the Amsoil and alot of people on one of the Nissan 300ZX sites say use Redline MTL hands down (seems like alot of Japanese car guys run this stuff). A local hot rod shop here carries Redline and Amsoil products.

On another note,I read on Redline`s site that 75W80 gear oils are the same viscosity as 10W30 motor oils. That seems like an oxymoron,but I`m a total noob when it comes to transmission fluids. Alot of 3000GT guys are getting the best results from Mobil 1 10W30 in their manual Getrag transmissions. What`s everyone`s take on that?

 

[aquariuscsm]

Instead of Amsoil MTG,I mean to type Amsoil MTF.

 

[unDummy]

Without used oil analysis, my take is that 'what everybody says' should be taken lightly. Best results are meaningless without data to prove they aren't chewing up the transmissions. Sure, shifts might be easier but gears, bearings, and bushing wear is something to worry about if parts/skills aren't available to fix it when it breaks.

If you require a gear oil, use a gear oil. If you want to thicken or thin it out a LITTLE, for improved protection or improved shifting, so be it. But to drastically drop the viscosity in any type of gearbox without studying the change in wear is foolish.

10w30 is typically weight for MTFs/MTLs. So, I can see how stepping down from a gear oil to a 30wt will ease shifting. But, I don't see how the SM/GF4 MPG improving friction modifiers used in motors oils could help with synchro shift feel. If anything, an HDEO or motorcycle oil should be considered. With all the MTFs/MTLs out there, there really is no point to using motor oil.

If you want to run a straight MTF/MTL in place of gear oil, sample and UOA it. If wear is minimal or comparable to a run with MT90/MTG, then use it.

Nissan already stepped down from 90wt gear oils to 75w85 to deal with some shifting issues. If they could go thinner without fear of warranty expense, wouldn't they have?????
This is why I would NOT go any thinner then the pretty common variable blends of MTL/MT90 or MTF/MTG. 50:50 is about as thin as I would go.

Your location isn't Canada. I truly don't see why you would want to go thinner. Is this your 1st manual transmission?
If anything, to protect the unit, I would shift it just a tad slower to allow engine rpms to drop so as not to work the unit as much. I would only use a 75w90 manual fluid. And, I would seriously consider a SAE50 OTR gearbox oil.

Most of the manual transmission issues that I've seen were 'ricer' problems. Inexperienced kids, with poor driving/shifting skills, that think that transmissions should work just as well as the shifter at the video arcade. Welcome to the real world.

 

[cos]

If the 300ZX forum members have found Redline to work well then why not stick with what has proven itself. I've used Redline for yrs in different Mazda transaxles and love it. I currently run 2 qts MT90 and 1 qt MTL.

 

[MolaKule]

The big dfference is the type of Friction Modifiers used, and they are different between the two oils.

I would use all Redline manual transmission fluids or all Amsoil manual transmission fluids, but never a mix of the two.

 

[aquariuscsm]

Hey unDummy,what are some good SAE50 OTR gearbox oils you`d recommend?

I`m just flabbergasted at the performance of Nissan manuals. I`ve been driving manuals all my life since high school some 20 years or so ago. The manuals I`ve owned were a 77 280Z,2 3000GT`s,a Ford Escort,96 Ford Mustang GT,and a late 70s era Mazda mini truck. I never had a grinding issue with any of them or ever had to have them worked on,and I literally pounded the holy heck out of them. Then there`s my Z. I bought it with 30k miles on it,and it`s already had 3 manual transmissions kick the bucket with 1st to 2nd grinding issues (now with 58k miles on it). The car is in showroom mint condition and the rest of the car is in impeccable mechanical condition. I`m the 2nd owner and the 1st owner was a middle aged lady who sold it to buy a Suburban.

My new transmission shifts like melted butter as long as I shift it very slowly,which can lead to getting rear ended in city traffic. I just honestly think Nissan`s using the cheapest manual transmissions they can get their hands on,seeing 350Z owners are having the same problems.

 

[unDummy]

http://www.macktrucks.com/assets/mack/approved_lubs/Mack_Trucks_Approved_TO-A_Plus_List_Rev1.pdf

 

[mechtech2]

Gear oils are tested at lower temps than motor oils [150F vs. 200F].
That's why the comparison seems odd - that a 90 weight gear oil is similar to a 30-40 weight motor oil.
I'd give the AMsoil a try. It's the newest technology.

 

[aquariuscsm]

Also,manual transmission lubes are also not supposed to have any limited slip additives,right? I hear of people putting RP Max Gear in manual transmissions,but it`s got limited slip additives,so I would think it would be a bad choice for transmissions.

 

[gtx510]

MT-90 or MTG...
90wt...