API SF grade motor oil for manual transmission

Well - I'm thinking of selling my '95 Integra GS-R after almost
9 years of reliable service. It's never broken down or failed
to start except when I let the water-level get low in the
original (serviceable) battery after 4 years.

However - I'm trying to get the transmission is shape before I
pass it on. I've used Redline MTL or whatever 10W-30 motor oil
(using it now) I could find in the past. The manual has always
called for 10W-30/10W-40 motor oil of API SF or SG grade - even
though SH grade was the standard when I bought the car. I
believe the feeling is that some of the newer motor oils may be
too slippery for manual transmissions, and Honda decided to go
with their propretary MTF manual transmission fluid.

So I walk into an AutoZone, and see some off brand motor oils -
inlcluding non-detergent SA grade oil and some SF grade oil in
10W-30 and 10W-40 weights. These don't carry the API seal (I
doubt they'll approve anything older than the SJ standard
anyways). There was a warning on the label that they shouldn't
be used in modern engines because of sludge control problems.

Any opinions on whether this is the right oil for the tranny?

 

I'd spend the $10 for the three quarts of Honda fluid.

 

OK - but motor oil is what's recommended in the owner's
manual. Honda didn't start using it until maybe 1998. I
used Redline MTL before since it's supposed to be a direct
replacement for 10W-30 motor oil in manual transmissions.

Of course there is the possibility that Honda didn't
redesign their transmission for the fluid.

 

The story I keep hearing is that the tranny didn't change, it was the oils
that did. but either way, Honda recommends their MTF for all of their
transmissions (even the ones that were built before the MTF existed). I put
it in an 87 accord this winter and I was amazed at how better it shifted
when it was cold... and the oil that I drained out was less than a year old.

 

First of all - I've heard quite a few people who are skeptical of
Honda's long drain interval recommendations for MTF. My '95
Integra's drain plug has no magnet, so any metal particles are
likely recirculating. That being said, it sounds as if the
original drain intervals for motor oil be fine for Honda MTF.

Second - I question why there was the original recommendation to
use API SF or SG grade oil at a time when major manufacturers only
produced to the SH spec ('95). I remember reading the manual of
my father's '82 Oldmobile, and SF was the highest grade then.
Everything I've heard is that current motor oils just work "too
well" to use in a manual transmission.

Third - I bought the oil (API SF grade) anyways. It's so cheap I
figure it's worth a try. The brand is called Valucraft, and was
$.79/quart at AutoZone for either 10W-30 or 10W-40. This brand
may just be a "private label" that AutoZone uses. The cashier
even warned me not to put it in my engine.

I'll try it out an see what happens.

 

So it's not "in shape" right now?... in what way?

Nothing to do with too slippery. The older engine oils had anti-wear
additives which have since been banned - mainly zinc dialkyl
dithiophosphate.

At the price you mentioned in another post, I doubt that it has the
anti-wear additive which qualified the engine oils for Honda trans use in
the first place. The Honda MTF works - use it.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

Nothing really bad. Just that I've been using API SL grade motor
oil for maybe the last year.

Banned or limited? I thought it had something to do with too
much fouling catalytic converters.

Really? I remember when I was able to get conventional Mobil
motor oil for 90c/quart. So - are you impying that API SF or SG
motor oil wasn't particularly well suited for manual transmission
use in the first place?

 

Yes it was blamed for catalytic converter poisoning and it was initially
reduced to the point of insigificance - there wasn't enough to do anything
and certainly not worthwhile for an manual trans. That *is* why Honda
stopped recommending it. With the move to borates, it's been pretty much
"banned" voluntarily by the lubricant companies.

You asked for advice - I gave it. Do what you will with it.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

As a follow-up - I tried the (off-brand) Valucraft API SF rated
10W-30 motor oil in the tranny of my '95 Integra GS-R. I warmed
it up and took it on the freeway. The shifter seemed to be a
bit harder to get in gear, shifts weren't as fast, and shifts
into 1st were really hard. It didn't seem to work as well as
the Shell 10W-30 I tried a few weeks ago. I'm not sure exactly
what makes the oil SF grade, but it did seem to "smell" like
current motor oils - a somewhat acrid smell. At least it cost
less than $3 for the oil and crush washers.

I'm going to the local Honda dealer to get some MTF.