BABY NSX

As posted in a previous thread I am having issues with a newly purchased used transmission (which was very recently rebuilt).

With the Pro1 cams I am now using the rougher idle is causing the transmission to chatter. The sound is VERY similar to a dry transmission that has its main shaft spun back and forth by hand. As you do this you hear the gears chattering.

When I installed the transmission fluid, the new Honda modified MFT, I noticed that the new fluid is MUCH thinner then the old Honda MTF. The degree of chattering does seem to be related to transmission temperature. As the tranny heats up the noise does appear to worsen.

This is leading me to think that the rougher idle combined with the thinner tranny fluid is causing the chattering.

Before I pull the tranny and inspect the bearings I want to try some thicker tranny fluid (like the OLD Honda MTF) and see if the chattering is cured.

I have called around locally to find some OLD Honda MTF, which is all I've ever used, but I can't find any. So I'm going to try to find some good alternatives which might have the same viscosity rating as the old Honda MTF.

Right now I'm thinking that Motul is my best bet and was recommended (by Motul in Canada) either:

Motylgear 10W40 or Motylgear 75W90.

I've searched and found a few members have had positive experience with Motul 300 Gear oil (last updated in 2004 based on my searching). The Motul rep suggested that this might be a little aggressive for my tranny, but I still have an open mind.

Does anyone have any thoughts/experience with the Motul tranny fluids?

Thanks in advance!!

Smitdog

I have nothing but great things to say about Motul Gear Oil in the trans. I work at a Honda Dealer and always just changed my fluids with OEM everything b/c it was free. I sold my original trans and swaped it with a brand new ITR trans with a 4.9 ATS FD.

I used Honda fluid in it, but at track weekends I would get a slight grind from 3rd to 4th when the car would gain heat about 10 mins into a session. I changed to Motul Gear Oil and have nothing but a silky smooth trans at all times. I pulled the case to inspect things and nothing had any wear. The HOnda MTF would just break down when put up agianst that heat and track duty.

BABY NSX

Thanks for the reply!

Do you remember which of the Motul blends you used?

db8sirg

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BABY NSX &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the reply!

Do you remember which of the Motul blends you used?</TD></TR></TABLE>

MOTUL Gear 300 for non-clutch lsd (stock).

MOTUL Gear FF Competition for clutch type lsd.


https://honda-tech.com/zerothread?id=879607


wai last time i talked with him uses Gear FF on his trans.

hondakar2

I am surprised no one has built a transmission oilcooler on their R....that I heard of anyways...

Im building one on mine this year

walker111

Can you not get some synchromesh? I use that in my trans with great results. I've heard great things about both, motul and sm.

Are you sure the trans was rebuilt correctly? I dont ever remember hearing what your describing in a car with aggressive cams. Even on rough road, which would simulate (imo better) the rough cams, I hear no noise from the trans.

Stock diff? fd?

BABY NSX

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by walker111 &raquo;</TD></TR><TR><TD CLASS="quote">Can you not get some synchromesh? I use that in my trans with great results. I've heard great things about both, motul and sm.

Are you sure the trans was rebuilt correctly? I dont ever remember hearing what your describing in a car with aggressive cams. Even on rough road, which would simulate (imo better) the rough cams, I hear no noise from the trans.

Stock diff? fd?</TD></TR></TABLE>

What I know about the tranny is this:

- It was rebuilt by Speedstar in Toronto
- All syncros and bearings were replaced
- ATS FD was installed
- Stock Diff
- The tranny was installed in my friend’s car and ran well for 3-4months before his engine blew. He is now doing a K swap so sold me the tranny.

I have not actually driven the car since the engine rebuild. I have only ran the engine in the garage. The sound it makes only occurs when the idle drops below 1000RPM and sounds exactly like the gears slapping around.

There does not appear to be any issues with getting the car into any gear. It feels completely normal.

I also know that the oil that is in there now is MUCH thinner then any oil I have used in the past.

I am not ruling out the possibility that the tranny is messed… but before I pull it from the car I want to try thicker oil (like the old Honda MTF) and see if that cures this problem. I’ve heard that GM syncromesh is thinner then the original Honda MTF so I ruled that out for now.

white rocket

Many of the guys a track with use Motul 300 in their trannys. It's been recommended to me by them several times.

walker111

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BABY NSX &raquo;</TD></TR><TR><TD CLASS="quote">

What I know about the tranny is this:

- It was rebuilt by Speedstar in Toronto
- All syncros and bearings were replaced
- ATS FD was installed
- Stock Diff
- The tranny was installed in my friend’s car and ran well for 3-4months before his engine blew. He is now doing a K swap so sold me the tranny.

I have not actually driven the car since the engine rebuild. I have only ran the engine in the garage. The sound it makes only occurs when the idle drops below 1000RPM and sounds exactly like the gears slapping around.

There does not appear to be any issues with getting the car into any gear. It feels completely normal.

I also know that the oil that is in there now is MUCH thinner then any oil I have used in the past.

I am not ruling out the possibility that the tranny is messed… but before I pull it from the car I want to try thicker oil (like the old Honda MTF) and see if that cures this problem. I’ve heard that GM syncromesh is thinner then the original Honda MTF so I ruled that out for now.
</TD></TR></TABLE>

I have no factual information on the thickness of synchromesh compared to Honda MTF, I do however have my opinion, which is I believe its better, thicker, and lasts longer than Honda MTF.

I look forward to hearing if a "thicker" fluid will stop the noise. Any chance of getting a sound clip?

BABY NSX

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by walker111 &raquo;</TD></TR><TR><TD CLASS="quote">... Any chance of getting a sound clip?</TD></TR></TABLE>

I'll try to get I clip tonight

an2ny888

i also had pro1's, they idled very lumpy but i did not not encounter the tranny sound you're experiencing.

BABY NSX

Here is a quick video showing my problem...

http://www.auderaacoustics.com...e.wmv

The tranny was very loud today even when it wasn't idling I'm sure you'll pick that up in the video…

IntegraleEVO

how long the trans has been sitting without fluids?

I would just drive it for 10 mins, let the fluid goes around the trans and lube up the bearings and see if that would go away.

white rocket

A little OT but how different is the heat rating from the old to the new Honda MTF? I wasn't aware they made a change until I read it here. I see that it's thinner but how does that effect viscosity, friction tolerance, etc. Basically is it better or worse for HPDEing?

Wai

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by db8sirg &raquo;</TD></TR><TR><TD CLASS="quote">wai last time i talked with him uses Gear FF on his trans.</TD></TR></TABLE>

I'm actually using the 90PA.
It was first recommended to me by A&J when I acquired the car from them. Back then, the Gear Comp FF was not available yet.

Then the Gear Comp FF came out. It's so much more expensive than the 90PA (over 3X more!), and I didn't have much problem with the 90PA, so I stick with it.