Honda Prelude Forum banner

transmission oil

10K views 74 replies 18 participants last post by  88SE Lude 
#1 ·
ok ive been readin some threads on the best tranny oil to use, some say the gm synchromesh and someone said synthetic 10w-30 and honda MTF, just wanted an updated opinion on what transmission oil to use.
 
#5 ·
Okay, we've had lots of these threads before (which a good search will yeild) so I better make a disclaimer before people start throwing fits. Any of the three fluids (synchromesh, honda mtf, syn 10-30) will work well in your tranny. Considering that our trannies are 15 years old, it's very likely one fluid could work before for someone and not someone else. I chose 10-30 because it was less expensive and easier to get. Just try one of the three, see if it works, and if not try a different one.
 
#7 ·
I got the honda mtf. It was like $6 a letre. Thats not any more expensive than mobile 1 syn. And it wasnt just 10w-30 oil, it has other additives in it. Just crack open a bottle and smell it.

Oh, and if you go to "how-to's" at the top of the preludepower page, there more info.
 
#8 ·
As i've reported before, i'm using Chevron 80w90 hypoid gear oil, put it in at 190k, i'm now at 257k, tranny still works great, shifts quick, etc.

Oil choice doesn't make nearly the difference some people would like you to believe :p
 
#9 · (Edited)
I'm not an expert but if you know how syncros work it makes sense to use an oil that will give the proper amount of "drag" needed to allow smooth shifting.

The syncro ring and syncro hub form a little cone clutch that must slow and stop the hub so the outer teeth of the ring can slide into the hub without grinding. I'm sure you have heard that slight "snick" when you shift overly fast. That's your syncro ring teeth (bronze) being ground down because you didn't give that cone clutch mechanism enough time to do it's job. One could make a pretty good case against short throw shifting levers. :-D

My impression is that synthetics are too "slippery" to work well in a syncromesh transmission.

I kind of like BobNova's approach, using traditional 80/90 gear grease. I'm betting his syncros work pretty quickly. Then again, why does honda call for lighter weight engine oil ? Gas milage ? Cold weather ?

I guess the bottom line is that if you know your syncros are in good shape but it's taking too long to allow grindless shifting, you can be sure that you are not using the best lubricant for your transmission.

It's a mistake to think that what works best in the engine will be best for the transmission.
 
#11 ·
Honda recommends either their own MTF (good stuff btw), or regular 10w30 or 10w40 oil. It's up to you what to use of course, but that's just what the OEM says to use, so I'm stickin to it for now.
 
#12 ·
Don't know if 80/90 gear grease is the way to go, but BobNova has supplied pretty good evidence.

I have an automatic transmission in mine so I'm out of the loop here. I'm just speaking from years of experience. My old 59 Austin Healy 100-6 used engine oil in the transmission because the oil supply was shared with the hydraulically operated overdrive unit. This did not do the transmission any favors.

See what I mean ??

:-D:-D
 
#13 ·
Oh... I do have one small question on this topic: If all I do is city driving (even very spirited city driving), the tranny shifts smooth as butter. However, after being on the freeway for ~15 mins or more (I do 80mph at least if on a freeway), the 3rd gear synchro becomes very unhappy with me.

This means that the MTF is breaking down and 3rd gear synchro is just in worse shape than the other ones, so it can't take the not-quite-as-lubricative oil, right? In which case, switching to some Red Line 10w40 ought to solve that problem eh?
 
#14 ·
Either:

Honda MTF (or equivalent).
A good mineral (or maybe semi-synth) 10W/40 engine oil
Or A good 75w/90 gear oil (or similar)

We almost exclusively use Millers CRX fully synthetic 75w/90 gear oil in our Hondas. That ranges form daily driver Civics right up to full race spec DC5 ITR's .

I use it in all my 3G's and find it very good.

So :emthup: to Bob .
 
#18 ·
My bet is that Honda said use 10w30 because it will move a tiny bit more freely, and give ever so slightly better fuel mileage.
Tiny bit of mileage X 1,000,000 cars = big tax break.
Just like the 10w30 engine oil imo.

My other bet, is that your third gear synchro is worn, and after the long highway speed trip the oil has heated up and thinned out, and is no longer thick enough for the synchro clutch doodad to work.

When mine is COLD, it's slightly harder to shift then normal (and it will NOT go into first if your moving, just flat out won't go), but once it's been driven for a couple minutes it shifts great.
Still shifts great after an hour of 80-90mph I5 driving, too :p

From what i've heard, Dano is dead on with the synthetics bit, as usual.



I mainly use gear oil because it's what we have at the shop, in the tranny oil pump.
10w30 would involve a long, slow funnel :p
Plus i like thicker oil all the way around, more protection imo.
I run 80w90 gear oil in my tr7's tranny too, despite it calling for ATF.
I can FEEL the difference in weight causing some drag, but it shifts a lot more smoothly. (The TR7 tranny is weird, it has an input shaft driven oil pump that lubes things, like an auto tranny, so it's probably having to pump the system up to a couple hundred more pounds then it ought to, if i let the clutch out in neutral it drops a solid 200 rpm hot, and 400 cold)
 
#21 ·
10-w30, 10-w30, 10-w30,10-w30. or genuine honda stuff they are equal

i run 10 30
 
#23 ·
I've run Syncromesh and 10w30 and 10w30 -w- Lucas additive...

I've seen to blow my tranny diff no matter what... but I now use Honda MTF and everything seems to last longer... just my personal experience, hope yours is different
 
#24 ·
If you manage to 'blow' trannies (whole different meaning in the UK btw) that easily then I can assure you it is NOT the oil you are using, and to suggest it might be is etremely naive.
 
#26 ·
Chunking a tranny is 99% of the time driver error and/or powershifting.
No oil in existance can help a tranny survive power shifting.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top