Hi Kaz, Where is the MTF meshed metal filter located?
Phil
Platinum Member
Hi Kaz, Where is the MTF meshed metal filter located?
Phil
Platinum Member
The location.
If the noise is from the DF, probably inspecting the strainer won't tell much.
There is a big magnet plate near the MTF pump so any big particles would be trapped there.
At the strainer, normally you would only see tiny particles from the synchro or gear teeth edge or anything that doesn't stick to the magnet such as the liquid gasket.
You'll need the replacement o-ring and the MTF filler washer.
The drain washer is the same one used at the oil pan/sump drain.
If never done before, good idea to get spare cover as you could break the tab.
If not treated in the past, by now, the blue section of the strainer cover is already heavily oxidised and bonded to the trans case.
This makes the removal of the cover time consuming if not done previously.
On installation, just coat the blue section and the backside of the tab with the silicone grease.
Never apply leverage force trying to lift the cover using the tab marked in red.
Instead, apply force in the direction marked in yellow to 'rotate' the cover back and forth.
This will break the oxidation and while trying to rotate the cover, change the direction of the force just a little to pull the cover outwards.
Repeat it and eventually, it will come off.
The example of what you would expect inside the strainer.
Just a tiny metal bits with metal powder.
The worst one so far….. It's not metal and in fact, excessive amount of liquid gasket.
Kaz
Platinum Member
Thank you Kaz��
Platinum Member
So just a little update on my side. I replaced the diff oil from Honda MTF-3 to Royal Purple and the noise had disappeared.
Platinum Member
Thank you for the update, Phil.
Interesting. OEM DF (differential) or aftermarket one???
I know fair amount of owners in US used 'cocktail' mix for the MT oil when they experienced difficulty in gear shifting.
For me, this is just hiding the issue and not a fix because for street driving, one should not have any shifting problem with the Honda MTF3.
Some even reported new issue on DF by using the cocktail method despite the significant improvement on the shifting difficulty.
The earlier spec DF has multiple CL disks with embedded friction material and soaked in the MTF.
It's pre-loaded and constant locking force regardless of the input force difference between the R & L shaft.
The spring washer/plate sets the friction force and the locking won't start slipping/break out until after exceeding the pre-loaded torque.
So, using different MT oil will change the characteristic of the locking/slip behaviour.
For the clarification, this doesn't mean good or bad on the DF friction disks.
Would be interesting to hear the update in longer term as I know some owners in Japan are using customised RP fluid in their MT box.
Kaz
A suggestion as to a possible cause.
At some prior point in time, was a friction modified transmission oil such as Red Line MTL or GM Synchromesh Modified used in the transmission? If the oil was used undiluted (not the 1:2 or 1:3 cocktail mix) the friction modified transmission oils canl lead to erratic operation of the limited slip differential (premature locking). There was one post on NSX Prime from > 15 years ago describing the differential problems that emerged from using 100% Red Line MTL. The problem was resolved after the oil was changed; but, did not completely resolve until after a couple of flushes. The first oil change with Honda MTL and subsequent change with Royal Purple may have succeeded in cleaning the original fluid out of the LSD clutch plates.
Just a hypothesis.
Platinum Member
Kaz, I'm not sure if it had an aftermarket diff, I can only put 2 and a quarter liters of oil in.Originally Posted by Kaz-kzukNA1
What is the correct amount from your experience?
So long story short.. my car had a clutch change at (A S MOTORSPORT end of 2019) not sure what oil they use after they replaced the clutch. Soon after that the engine needed a rebuild so the gearbox oil was drained out and stored in a plastic container.
4 months later when the engine was ready to go back in I thought it would be better to have new oil in the g/box. I put 2 liters of Honda MTF 3 in but not enough so added about half liter of the old oil in, perhaps it was mixed with 2 different type of oil.
Platinum Member
Not scientific measurement but I normally pour about 2.7 - 2.8L of MTF into the Gbox and wait for the excess to drain out.
So, if you were only able to put 2.25L in, very likely to be aftermarket LSD.
With our MT box, only part of the mechanical gears are submerged in the MTF.
There is a small trochoid pump at the bottom of the trans case driven by the final driven gear.
Thus, unless the wheel starts rotating, trans oil won't be pumped out to properly lubricate the gears, bearing, etc.
This is the reason why you need water like viscosity even at cold temperature but really strong oil film at the same time.
That is the characteristic of Honda MTF-3.
On the other hand, instead of using the ordinary widely used synchro key mechanism, Honda went with unique (though I would say 'strange') spring method for their synchro.
It relies on the tension of the spring and with such thin body, don't know how the manufacture can control the tension spec.
Probably this is the reason why many people experienced shifting difficulty and searched for the aftermarket 'cocktail' solution.
On track, even just after few laps, the trans oil gets so hot that you would notice the changes in shift feeling if usimg the Honda MTF-3.
Potential cause of using such strange spring tension based synchro with trans oil chemical change/breakdonw under extreme temperature.
It's not that expensive so just replace it after the event.
Yes, I heard similar story from one UK owner.
His NSX had to be rescued to Honda dealer due to sudden huge judder/vibration from the gbox only when making the turn. Straight line was fine.
At the end, the dealer had to flush the gbox like 5 times and the judder was gone.
Kaz
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