Manual transmission fluid vs. Motor oil - Page 2 - Honda Prelude Forum

rybred · 12-31-2003, 06:25 PM

nothing but better shifting after syncromesh...try it...you won't be dissapointed

vtecprelude · 01-03-2004, 08:31 AM

Preludes tranny gets very sensitive as you approach the triple digits. I would use the MTF stuff to prolong the life of the sychros. Using synthetic oil is the worse thing you can do for the tranny, it prematurely wears out synchros.

paulyg · 01-03-2004, 10:45 AM

Quote:

Originally posted by vtecprelude
Using synthetic oil is the worse thing you can do for the tranny, it prematurely wears out synchros.

Huh? Is this a wivestale or do you have proof of this?

I don't see why it would matter as long as they provide the same shear force resistance which is a function of viscosity.

Prelude UK · 01-03-2004, 12:06 PM

Has anyone used Castrol MTF? I have seen synthetic Castrol SMX-S for sale (or something like that). I dunno if it is available in the USA though?

dvsracergirl · 01-03-2004, 01:42 PM

Quote:

Originally posted by Keith

I'm not convinced of that either...

im not too sure whether or not this is correct...i was gonna try it but i couldnt find it at the time that i put new clutch and LSD in. so i just put redline in and all my issues went away.

beaty · 01-03-2004, 08:41 PM

Synthetic motor oil is indeed an unfavorable fluid for the gearbox. Mainly because it does not have the appropriate friction modifier.

vtecprelude · 01-03-2004, 10:37 PM

Quote:

Originally posted by paulyg

Huh? Is this a wivestale or do you have proof of this?

I don't see why it would matter as long as they provide the same shear force resistance which is a function of viscosity.

It's not like I can just hand you the proof, it's accumulated knowledge over the years.

Synthetic oil is too slippery, causes the synchros to work harder.

slipnfall · 12-28-2010, 10:10 PM

Sorry to revive such an old thread, but some input:

'Brother has been working as Master tech at honda for 20-some years now. He said to this day they simply use conventional motor oil in the 3rd-gens' gearbox. QuakerState - that's what they happen to sell.

He also said that he would caution against Honda's MTF in a 3G (this coming from a guy who is a hard-core proponent of using Honda fluids), citing that it's too thin.

Velocity1 · 12-29-2010, 06:31 AM

Nothing but Honda MTF in my trans. So far so good. Figure I'll leave well enough alone.

tschulz · 12-29-2010, 10:13 AM

Quote:

Originally Posted by Keith

It states in the Helms manual that motor should not be used since it doesn't have certain additives that transmissions fluid has. I don't see a reason why you would use motor oil vs MTF since MTF is pretty much the same price.

Keith

This is exactly right. Motor oil is just that. A lubricant designed for motors. While the general idea of a motor and a transmission are the same ie: moving parts that require lubrication, they are still very different obviously in design, as well as in their needs. Honda mtf or penzoil gm snychromesh would be the best suggestions. I use synchromesh and my shifts are extremely smooth.

bouckarooo · 12-29-2010, 02:11 PM

In a 3rd gen, you casn use motor oil, as for the fourth gena nd fifth gen; MTF is what you need as there are friction modifiers in it. I have used redline, without anyluck(although in kwow others who swear by it). Personally i use Honda MTF, but i hear the GM synchromesh is good. On a side note, i have a buddy of mine who has a 91 hatch with a b20 with a y80 transmission, and he uses amsoil in his tranmission, hasnt had any issues yet either. I think this may be one of the things that can go either way depending on driving style and mileage.

minilogoguy18 · 01-02-2011, 08:15 AM

Yes, for Honda's of the late 80's and older they do just use oil but anything newer than that MTF is highly recommended. I ran 10W/30 in my T2W4 when I first swapped it as it was all we had on hand and it shifted like total garbage from 1st to 2nd, started using MTF and problem went away instantly.

CTrees · 01-02-2011, 11:37 AM

A couple of years ago I lived in Austin and was coming back up to Dallas. I stopped at a jiffy lube to get my oil changed on the way out of town (before I started doing my own). One of their techs came into the lobby and asked me if I was getting a transmission service done, I said no and he went back into the garage. I can only assume they started to drain it, realized they weren't doing a tranny job and filled it back up with motor oil. About 120 miles down the highway I try downshifting into 4th and it feels like there is cement in my transmission. When I got into town I took the car to a local shop and they drained the fluid and told me there was motor oil in the transmission. I had to go back to Austin so I took another car and left the Prelude in Dallas. They were the last shop to touch the tranny so it could only have been Jiffly lube that put it in there.

Long story short, the cost of fixing my transmission was way higher than the cost of dropping in a used one. You guys can use motor oil in your transmissions if you want but hopefully my experience will deter you.

Just wanted to add that I can't say for any certainty that jiffy lube putting motor oil in my tranny is what caused the massive failure, it could have been a timing coincidence but I will let you draw your own conclusion.

minilogoguy18 · 01-02-2011, 12:35 PM

When it comes to jiffy lube, you get what you pay for. I constantly see cars with loose or overtightened drain plugs which the latter requires replacement of the oil pan. They also use the SMALLEST and cheapest filters which probably don't do any good as far as filtration.

One thing my mom learned as well before I was even into working on cars is never let a tire shop work under the hood of your car, they cracked her valve cover(Tires Plus).

CTrees · 01-02-2011, 12:48 PM

Yeah, i'll probably never take my car to shops like jiffly lube again. I would urge everyone to do small stuff like that themselves but I know it isn't always feasible.

I <3 My BB6 · 01-13-2011, 11:33 PM

AMSOIL SYNCHROMESH fully syn tranny fluid. best IMO, it is amazing. I highly reccomend this to anyone with slight grinds in their trannys.

minilogoguy18 · 01-14-2011, 07:27 PM

^Still not buying it as the very people who make it say it is formulated for transmissions that require the use of 5w/30 oil in them. For any transmission made from 1990+ Honda recommends the specially formulated MTF over any motor oil and anyone who's used the Honda MTF knows that when you crack that bottle open it's very different than motor oil.

Putting a heavier fluid in a manual trans that grinds is like putting a band-aid on it. Problem is still there and will get worse as the synchros are already damaged enough to cause grinding.

karloz · 02-14-2011, 09:41 PM

I was having problems shifting in colder temps (anything under about 55 degrees F).
I was also having the occasional slight grind from 1st to 2nd.

I just put in some Amsoil MTF and so far things are much better with the grind (pretty much gone). I still have to see how it behaves in colder temps though.

It's obvious the PO did not change the MTF often in my Lude, the stuff that came out was black and thick. Poor thing.

I also put in some Amsoil XL 15k synthetic motor oil, I figured I was already changing fluids so why not.