Wildguzzi.com
General Category => General Discussion => Topic started by: sign216 on July 09, 2025, 06:44:12 AM
-
At 85K miles it's time to change the transmission gear oil on my '18 Honda Accord manual transmission. Factory calls for special Honda manual transmission fluid. If you can't get that, the factory says to use 10w-30 motor oil. What?! I haven't seen that recommendation since motorcycles from the 1950's and 1960's, when motor oil was routinely used as gear oil.
I checked multiple sources, and yes, using 10w-30 motor oil is correct. The Honda's gear oil is 10w-30 weight, not the usual 75-90 or 80-90 weight. Any thoughts on this?
Also, since automatic transmissions are normal now, they've stopped saying "gear oil" and now say "transmission fluid" even for manual transmissions. Speech is getting dumbed down.
-
I would go with what the manual specifies. Gear oil and motor oil have different viscosity specs. 70wt gear oil is not as viscous as 70 wt motor oil.
(https://i.ibb.co/nqRSwZSj/IMG-0628.jpg) (https://ibb.co/nqRSwZSj)
Pete
-
Since this is a Guzzi site, someone has to say it: Yak Fat. Semi-rendered Yak Fat for your particular application. I know a guy in Australia who can ship it to you by the gallon.
-
Not unusual I had a '98 Dodge PU with the NV4500 manual transmission. The specified lubricant was a light duty fluid, I don't remember now what it was, but it also had to be one that didn't attack yellow metals. It also had to have friction modifiers in it as the synchronizers were some type of fiber material.
kk
-
(https://i.ibb.co/gLTSVpfM/mtgqt-ea.jpg) (https://ibb.co/gLTSVpfM)
https://www.amsoil.com/c/manual-transmission-fluid/123/?gad_source=1&gad_campaignid=21521064946&gbraid=0AAAAAD4pZOikbzYJN8Ed_ScgY5gZ7gwO_&gclid=CjwKCAjwprjDBhBTEiwA1m1d0qDfHzrO6A2QEFSLNk0j8jHdgz_cx6wYCprWpYQrCCSnegYwfpqy2hoCXW8QAvD_BwE
Had '98 Accord. Put this stuff in at 90K miles. Transmission worked great. Doesn't bother yellow metal. Gave car to Son-in-law and he ran car to 350K miles then got bored with it and sold it as a runner. Never had transmission issues.
Ran it in Airhead transmissions and performed without incident.
Now run it in Guzzi & Ural transmissions beyond 100K miles without surprises.
Good enough proof for me as I have opened various transmissions and witnessed negligible wear.
-
Yaks are getting a little pricey lately, so I offer this . The internet search I did gave it 5 Stars!
(https://i.ibb.co/nN5zP851/20190825-104919.jpg) (https://ibb.co/nN5zP851)
Paul B :boozing:
-
really? I've owned 3 manual Accords over the last 38 years. I've never changed the gear oil or even knew it was on the schedule. The first two had over 120-200k miles when we got rid of them, the first one was totaled out in minor fender bender.
I'm driving a '14 model now with about 85k miles on it. All I ever done was change the oil and installed the 3rd battery, 2nd set of tires
-
really? I've owned 3 manual Accords over the last 38 years. I've never changed the gear oil or even knew it was on the schedule. The first two had over 120-200k miles when we got rid of them, the first one was totaled out in minor fender bender.
I'm driving a '14 model now with about 85k miles on it. All I ever done was change the oil and installed the 3rd battery, 2nd set of tires
At a hundred thou, you really should consider changing the trans fluid, brake fluid, power steering fluid, serpentine belt, and I'm sure the brake pads are getting thin...
-
This came about because a mechanic in the shop called me, and said they couldn't include the trans fluid change amongst the repairs, because the car took a special gear oil that they forgot to order (probably because they assumed they could use the 75-80 or 80-90 oil they had on the shelf).
I thought he was giving me some kind of line, but when I looked it up, I couldn't believe Honda wasn't using a standard oil weight. This is an Accord for Heaven's sake, it's not a Corvette or a Ferrai. No worries, I'll get it done at the next oil change.
But why is Honda even mixing it up with this? Just use the same manual transmissions they've been using for 40 yrs. No one is looking for some cutting edge machinery here. I think the next model year they stopped manuals for the Accord anyway.
-
The reason for thiner oil is better fleet average mpg simple as rhst
-
Rockauto shows a Valvoline manual transmission synchromesh oil for that gearbox. Why not just get some and change it. Its no harder than changing engine oil.
Pete
-
Go buy a new toyota and try to find the recommended 0W8 oil!!
Paul B :boozing:
-
I think I found the relevant section of the manual here:
https://techinfo.honda.com/rjanisis/pubs/om/ci0505/CI0505O00167A.pdf
It states to only use motor oil as an alternative temporarily. I read that as don't bother, buy the MTF that they have specified, do it by the book, and be done with it.
-
The reason for thiner oil is better fleet average mpg simple as rhst
I think you have it. Car makers are doing crazy stuff to keep mpg down, so a thinner gear oil is cheap, easy, and the consumer will never notice. Knowing that 75w-90 gear oil is roughly as heavy as 10w-30 motor oil, I shudder to think how thin the recommended 10w-30 Honda gear oil is.
I'll do it, if that's what the book says. I'm not liking it.
P.S. I've always had manuals, and this Accord is the easiest shifting car I've every had. I don't think it's the gear oil, I think they just adapted the transmission for the newbie driver thinking about a manual trans. It really is a good one for a beginner.
-
It sounds like the book is not even liking it.
"If Honda MTF is not available, you
may use an SAE 10W-30 or 10W-40
viscosity motor oil with the API
Certification seal that says ‘‘FOR
GASOLINE ENGINES’’ as a
temporary replacement. However,
motor oil does not contain the proper
additives, and continued use can
cause stiffer shifting. Replace as
soon as it is convenient."
-
The reference to 10-30 motor oil is a red herring. Don’t assume Honda MTF is 10-30, rather more like 75-90 gear oil. No idea what it actually is because its not on the bottle but many use other brands of 75-90 synchromesh oil.
FWIW Honda specifies an ATF for their automatics. Ridgeline transmissions are known to fail early so if you use another brand of ATF they can deny warranty work.
BMW did the same thing back in the ‘80s when wheel drive splines failed. Used their high dollar grease or they will deny they were at fault. The high dollar grease didn’t help either.
Pete
-
The reference to 10-30 motor oil is a red herring. Don’t assume Honda MTF is 10-30, rather more like 75-90 gear oil. No idea what it actually is because its not on the bottle but many use other brands of 75-90 synchromesh oil.
FWIW Honda specifies an ATF for their automatics. Ridgeline transmissions are known to fail early so if you use another brand of ATF they can deny warranty work.
BMW did the same thing back in the ‘80s when wheel drive splines failed. Used their high dollar grease or they will deny they were at fault. The high dollar grease didn’t help either.
Pete
Pete,
I think the Honda gear oil is 10w-30 because Amsoil list 10w-30 as the manual trans oil, and that's what the factory recommends as a replacement.
I'm thinking of replacing the gear oil w 75w-90. It's probably better for the trans, and F____ the gas mileage. I'm not counting on the factory warranty for anything.
But, for Mass. residents, I recommend McLaughlin Chevrolet of Whitman, Ma. They replaced the automatic trans on a Chev Monte Carlo Super Sport on warranty, without me even asking. The trans failed at 70k miles, I had it towed there, and they did the replacement without even asking me. Amazing.
Joe
-
gear oil weights are not the same as motor oil weights. Gear oil is about double motor oil so a 90w gear is approximately a 40 weight motor oil. The assumption that most of you are making that Honda is using odd, thin oil is wrong. It's not uncommon that gear oil is thinner than motor oil,
https://bobistheoilguy.com/viscosity-charts/ (https://bobistheoilguy.com/viscosity-charts/)
Honda has been specifying the equivalent of 10w30 for decades. They've also made millions of motorcycle transmissions that work just fine on 10w30 and 10w40.