GC as MTF

Messages
1,228
Location
ottawa
Hey guys would GC syntec make a good replacement for honda MTF ?, the car will be used in very cold weather 8 months of the year. or will the 0w weight make it too thin, before the oil comes to temp ? just wondering?
 
Messages
396
Location
DeKalb, IL
It says in the Honda manual (I own two Accords) that 10w-40 can be used in an emergency, but must be removed ASAP. I'd just use the Honda MTF; it's good stuff and won't get you into warranty problems with Honda.
 
Messages
782
Location
Alberta
The Honda MTF is like a 5w-30 and is thinner than GC 0w-30. … … … … … … … … 100C … … 40C … cSt … Honda MTF … … … … … 10.5 … … 53.2 Syntec 0w-30 … … … … 12.1 … … 66.8 Pennzoil Synchromesh … 9.08 … … 41.6 And it has a very high VI of 190 too, so it’s not likely that the Syntec would be thinner at winter temps like -30C. At -40C or colder the PAO based Syntec might be a little thinner ( Honda MTF = Grp II..?), but that’s probably not really relevant. A motor oil has been spec’d in a fair amount of MT’s in the past but doesn’t seem to be much anymore. One could probably get reasonably good service life with a motor oil in a MT as long as the fluid was changed regularly, but motor oil is probably not really the ideal fluid for a MT because of the lack of EP additives. My 1987 Jetta owners manual calls for a GL-4 80w-90 for the MT. These 80w-90’s are so thick in the winters here it almost amounts to a bad joke -- it’s like trying to shift a broom through molasses. They’d be ok in the southern US but are not really appropriate here. 75w-90’s help in the winters, but I find even they get quite thick around -25C which we regularly see in the dead of winter. I just changed the MT oil in my Jetta 2 weeks ago, and in a effort to get something thinner I put in a 50/50 blend of 75w-90 and 5w-30 motor oil. The Petro-canada product handbook says a GL-4 fluid has about 50% of the additive treat rate of a GL-5 fluid. So, by blending a GL-5 gear oil 50-50 with motor oil, I figure I have a thinner GL-4 type fluid that has a good amount of EP additives in it. The 75w-90 is probably around 16.0cSt and the 5w-30 around 10.7cSt, so I’m getting a fluid around 13.0cSt -- thinner, but still quite thick compared to the Synchromesh fluids. I’m going to try this mix through the winter and see how it does. So far, my shifting is the best of any gear oil I’ve tried -- even better than the 75w-90 Synthetic I drained out. The trend in MTF’s is definitely towards thinner and I’m surprised this hasn’t caught on more. These MT’s don’t really seem to need a 75w-90 GL-5 gear fluid. Despite the 75w-90 GL-4/5 spec’s for many VW MT’s, when I checked one of the VW forums there were a fair amount of users that were using Pennzoil Synchromesh with good results. Some of the new MT’s on VW’s are actually shipping from the factory with a 6.3cSt gear fluid. Someone over on the tdi forums did a UOA on his MTF and the results came back with 6.4cSt …!!! … -- he just about pooped his pants because he thought the MTF was a 75w-90 … tdiclub[LOL!] . Petro-canada makes a Duratran XL Transmission/hydraulic fluid that is 8.6cSt and is GL-4 rated. I’m probably either going to try this or the Pennzoil Synchromesh on my next transmission fluid change.
 
Messages
1,462
Location
MD
[QUOTE]Originally posted by Drivebelt: The Honda MTF is like a 5w-30 and is thinner than GC 0w-30. … … … … … … … … 100C … … 40C … cSt … Honda MTF … … … … … 10.5 … … 53.2 Syntec 0w-30 … … … … 12.1 … … 66.8 Pennzoil Synchromesh … 9.08 … … 41.6 And it has a very high VI of 190 too, so it’s not likely that the Syntec would be thinner at winter temps like -30C. At -40C or colder the PAO based Syntec might be a little thinner ( Honda MTF = Grp II..?), but that’s probably not really relevant. A motor oil has been spec’d in a fair amount of MT’s in the past but doesn’t seem to be much anymore. One could probably get reasonably good service life with a motor oil in a MT as long as the fluid was changed regularly, but motor oil is probably not really the ideal fluid for a MT because of the lack of EP additives. My 1987 Jetta owners manual calls for a GL-4 80w-90 for the MT. These 80w-90’s are so thick in the winters here it almost amounts to a bad joke -- it’s like trying to shift a broom through molasses. They’d be ok in the southern US but are not really appropriate here. 75w-90’s help in the winters, but I find even they get quite thick around -25C which we regularly see in the dead of winter. I just changed the MT oil in my Jetta 2 weeks ago, and in a effort to get something thinner I put in a 50/50 blend of 75w-90 and 5w-30 motor oil. The Petro-canada product handbook says a GL-4 fluid has about 50% of the additive treat rate of a GL-5 fluid. So, by blending a GL-5 gear oil 50-50 with motor oil, I figure I have a thinner GL-4 type fluid that has a good amount of EP additives in it. The 75w-90 is probably around 16.0cSt and the 5w-30 around 10.7cSt, so I’m getting a fluid around 13.0cSt -- thinner, but still quite thick compared to the Synchromesh fluids. I’m going to try this mix through the winter and see how it does. So far, my shifting is the best of any gear oil I’ve tried -- even better than the 75w-90 Synthetic I drained out. The trend in MTF’s is definitely towards thinner and I’m surprised this hasn’t caught on more. These MT’s don’t really seem to need a 75w-90 GL-5 gear fluid. Despite the 75w-90 GL-4/5 spec’s for many VW MT’s, when I checked one of the VW forums there were a fair amount of users that were using Pennzoil Synchromesh with good results. Some of the new MT’s on VW’s are actually shipping from the factory with a 6.3cSt gear fluid. Someone over on the tdi forums did a UOA on his MTF and the results came back with 6.4cSt …!!! … -- he just about pooped his pants because he thought the MTF was a 75w-90 … tdiclub[LOL!] . Petro-canada makes a Duratran XL Transmission/hydraulic fluid that is 8.6cSt and is GL-4 rated. I’m probably either going to try this or the Pennzoil Synchromesh on my next transmission fluid change. [/QUOTE VW OEM's ATF like MTF despite it's 75W90 recommendation.
 
Messages
9,427
Location
Pensacola & Vero Beach FL
quote:
Originally posted by vad: I don't think that motor oils make the optimal tranny fluids. I would advice against that.
============================
quote:
Originally posted by speedtc: Why would you not use trans fluid? Will GC bring world peace? Sorry!
Speed & vad: Many Honda manual transmissions call for xw-30 motor oil as their fluid. I drove an 88 Honda Civic 5-spd manual for ten years and used Mobil-1 5w-30 in the transmission the whole time (150k miles). Some say that dinos are better in the MTs, but I never had so much as a hint of shifting problems using the M1. Capacity was IIRC just under 2 qts, and I changed it annually, so it wan't like a big expense either.
 
Messages
4,107
Location
Savannah, GA
As much as a pain in the rear that changing the MTF in my Acura is, I am going with Redline MTF next. The Honda MTF thins out too fast, and you need to change it around 25,000 miles. I had 1.3 quarts of Honda MTF left and had to finish the fill of the tranny with about a 1/2 a quart of Chevron 10W30 SL oil and I can't tell a difference in shift quality at all.
 
Messages
1,391
Location
Lynden, Washington
I heard a while back- here on BITOG- that when engine oils were recommended for Hondas (my Civic included), this was when such oils had high levels of ZDDP in them. Now that this is not the case, it seems that a quality manual trans fluid substitute is the only way to go. I changed out my fluid and replaced it with Red Line MTL- good stuff. Next change will likely be w/AMSOIL MTF. I myself would be hesitant to use GC in a gearbox, but most certainly would use such in an engine.
 
Messages
1,910
Location
Vista, CA
I ran my 84 Civic on conventional 5w-30 oil from new to 30k miles, then Mobil 1 5w-30 up to about 375k and switched to Red Line MTF and now have 386k miles. I did replace the bearings and seals at about 200k miles. The roller bearings will wear out no matter what you do. They are a contact bearings and after enough miles will start making noise. The gears and syncros were in perfect condition and went right back in.
 
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