Correct Transmission oil

Hey All...I took my car to get its trannie oil changed for the first
time since I've had it (2 years, 91' civic 3-door)....and from what
the manual states...it needs 10W-40 oil...which is exactly like the
enigne oil I use....is that normal? For some reason I was under the
impression trannie oil was different than engine oil...

Steve

 

If this is a manual transmission, that information is out-of-date.

Your transmission should only ever be filled with genuine Honda MTF.

10W-30 (not 10W-40) engine oil is not the same now as it was in 1991.

 

The oil manufacturers have lessened the "ep" or extreme pressure
additive in motor oils at the request of car manufacturers because the most
prevalent additive used a zinc compound, and that shortened the life of
catalysts (and maybe o2 sensors).
The ep additive is not really important in an auto engine except in very
high revving engines at the cam to follower interface where there is
usually not a hydronamic condition, i.e. the parts are not entirely
separated by an oil film.
They are needed in a transmission, however. If you do not want to buy
Honda trans lube do some research into motorcycle oils as they have
identified this problem (many use the same reservoir for transmission and
engine) and many motorcycle oils have more ep additives,
but are probably just as expensive as Honda's trans oil.
If you drive normally and do not drive at 100 mph plus you can probably
do without the additives, but even if it added $20 to the cost of a trans
oil change I would do it, trans repairs are too expensive to risk.
When '87 manuals were printed engine oil had enough ep additives to work.
Honda is on the ball and trying to protect your transmission, you should
listen in this case but a little scepticism is a good thing, I don't think
and have not been able to find out if the brake fluid they use is special
in some way. Anybody know why we should pay extra for Honda brake fluid?
Scott

 

See http://home.earthlink.net/~honda.lioness/id20.html for
the scoop on this topic. Much of what I wrote there
reinforces what Scott wrote in his post. I'd just emphasize
that using the Honda manual tranny fluid does not cost more.
I explain this at the site above.

 

You can also use the synthetics from RedLine. They have all the
additives that were common to the older engine oils. I made a big
difference in my '83 which has a noisy imput bearing... Much improved
over the Honda stuff. (10-40 motor oil was originally called for in
this car also).

JT

 

The other consideration is the total lack of friction modifiers that are
critical to synchro operation. Use a modern 10-40 and you will
experience synchro difficulties at some point in the future.

JT

 

According to the manual, non-Honda brake fluid can cause corrosion. I
wouldn't take that risk to save a few bucks.

 

Well yesterday I decided to go ahead with the transmission oil change
using the 10w-40 motor oil....I did this based on the following:
- I phoned up the local honda agent (I'm currently
living in Malta) and they assured me that motor oil is good enough for
my car.....although they do stock Honda MTL they were just adamant
that it wasn't worth it...So either they really didn't wanna sell or
they have enough experience to know what they were talkin bout...
- My mechanic put in a synthetic-based 10w-40
motor...I don't know if it makes that much of a diff....
- Does the warmer climate make a difference? (its like
30C here)

Outcome: After driving it for one day....gear changes are definitely
much smoother....even reverse has had a marked improvement. Having
said this....I might be up for a new clutch soon (matter of months) so
when that comes around I will surely switch to the MTL....

One last thing....I'm not sure if its related...but sometimes I notice
that I get some slight knocking/vibration in the gear lever at certain
RPM's and under load like going up a hill.....any ideas?

Steve