Royal Purple in a manual transmission
 

I have a 2000 Accord 5 speed with 75K miles on it and it's shifting a little on the hard side it even grinds some times taking 5th gear. I read on here that I should swap my fluid out for royal purple synthetic. I couldn't figure out what grade it was that I needed of MTF on there web site so I called there technical service number and what he told me was that Honda manual transmissions use Honda gear oil which is basically engine oil and that I should use 2 quarts of royal purple 10w40 motor oil in my transmission. It seems weird to me to use motor oil in the gear box for you guys that have done this what do you recomend?

The 94-97 accord shop manual says to use 10W-30 or 10W-40 API service SG or SF.

I don't know if the 98-02 accords call for the same. The owner's manual may tell you what fluid you can use in your transmission.

use Honda MTF if you can afford it ,, if not ...use engine oil 10w-30 any brands will do

The operator guy said that all Accord's 92-present use the same tranny oil. Also API service 10w30 is the sam as engine oil?

Royal purple was about eight bucks a quart so I doubt that OEM is more expensive but isn't the royal better for smoother shifting and to mask minor flaws?

I'd use Honda MTF.

Honda always called for 10w-30 engine oil. API service SG or SF - that IS engine oil.
After about 1996 or so, they began selling their own MTF which is compatible with all the older transmission that used engine oil. Same viscosity & other characteristics, but the Honda MTF added some EP additives (you can smell them in the bottle).

Syncros are basically like little clutches. If the oil is too tenacious & too "slippery" they don't work well. So synthetic engine oil isn't really better for synchros. Synthetic MTF has friction modifiers to make the synchros work OK.

If you really don't like Honda fluids, try something like Redline MTL? (But it's not cheaper than Honda MTF)

I have tried Honda MTF and Redline MTL in my gearbox and find Redline to provide smoother shifting and last longer.

Royal purple makes a mtf but its not 10w40 based I quess. Maybe ill look into amsoil and just put the royal purple in the engine instead of the Mobil 1 I always use. I wish I could do a automatic conversion have contemplated it many times but never find a suitable donor car.

Post that in the wanted section, most people want to convert TO manual trans.

I didn't realize RP made MTF, it might just be OK. MTF or MTL is generally the terminology for an oil that's compatible with the transmissions that take engine-oil. Other types of gear oil will be labeled GL-4 or GL-5.