Hi All, I have a 1993 Honda Acty with a 5 speed manual gearbox, its rear wheel drive only. What gearbox oil should i be using? i have read that it needs 75/80 gear oil, but i have also read that it uses normal engine oil in the gearbox? Could sombody please clarify this for me please? as im not sure what i should be using!! Thanks!
My 1998 japanese owners manual says Honda MTF-II. I googled for that and this comes out 75W GL-4 Manual Transmission Fluid - Honda MTF II Honda MTF II 08260‐99957 Honda MTF II Ultra 08460‐99954 Honda MTF II Ultra 08460‐99957 Superseded by Honda MTF III http://syntheticoil-europe.eu/en/182-honda-mtf-ii http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2097642 Apparently Amsoil Manual Synchromesh Transmission Fluid 5W-30 is suitable https://www.amsoil.com/shop/by-prod...ission-fluid-5w-30/?page=/storefront/mtf.aspx Another statement: 75w90 is roughly the equivalent of a 10w40 engine oil base - which is Motul Motylgear 10w40 and Royal Purple 10w40 (common MTFs for our transmissions). Gear oil has different ZDDP and EP contents, etc. for sure. But the Motylgear 75w90 will more than likely be fine, as it has virtually identical kinetic viscosity properties to Torco RTF. Not all gear oils will work, and in fact, some will prevent the proper operation of the synchronizers and oiling of the bearings, specifically the needle bearings behind the gears. So definitely not usually recommended. http://honda-tech.com/showthread.php?t=2925749 That is all I could find, my Acty has an automatic transmission and uses ATF - Z1.
I use the same oil in the gearbox as the engine. No issues here. The oil I drained from it was definitely engine oil. Also, when you re-fill it, if the truck is on level ground... fill it till it starts overflowing, it measures out to the exact amount you're supposed to put into it. I've marked the drain port in red, and the fill port in green. I thought the fill port might be the big allen head bolt up and to the right, but it's the access port to disassemble the entire transmission apparently.
Discovered that the easiest shifting in my 1992 acty can be obtained by using redline v-twin transmission oil with shockproof in the gear box.This oil is a bit more expensive but from running it in my harleys i thought the benefits may extend to my mini and believe me it does,ive ran this oil from -53 degrees c to present temps of about 10c and its quiet and shifts much easier!!!
I’ve read that 10w40 can be used temporarily but Honda MTF is recommended. Is there that big of a difference? Just changed mine out with 10w30 full synthetic motor oil.
From what I’ve read, the Honda MTF is 10W30, with some friction modifiers. You can probably use any good synthetic, 10W30 oil, and be just fine.
Because the friction between the teeth of the gears is entirely different than that in engine journals, and the timing chain. Greatly simplified: In engine journals there is always a thin film of oil, and the actual metal never touches. Things just float on the oil. In the transmission, the gear teeth, actually exert extremely pressures, and enhanced shear is important.
So what benefits are provided by friction modifiers in a transmission? Not trying to be a pest just never too old to learn. Want to do what’s best for the truck. It is almost 30 and I want it to enjoy it’s golden years.
Up until the 2000s, don't remember exactly when, Honda used whatever engine oil in the manual transmissions, until they started selling their own branded MTF. Don't know the viscosity or any other specs, they don't divulge that info. Same thing with their ATF, used to use Dexron, CVTs used ATF until they came out with CVT fluid, 4wd rear ends used ATF until they came out with dual pump fluid and so on. Nothing special about any of it except their brand on it. Never use GL anything in a Honda manual transmission.
I think I get it now. My wife’s rear end started making horrible noises a few months ago. (Her CRV) never knew of or heard of dual pump fluid but after a drain and refill with the “mysterious fluid it is fine now.
I found an excellent price on MTF on Amazon. Did that back in February, I believe. Zero complaints or problems. It's been my daily driver for the past two months.