Synchro Mesh vs new honda White cap

[stuntman]

The additives in synchromesh could cause the LSD clutch plates to slip excessively and make the diff act more like an open diff.

 

[Honcho]

Well I'd better check into this. Good catch. I've had it in the trans. a couple years with no issues. I change the trans oil every 2 years anyway so nows a good time to see. Thanks for posting this.

Check my post # 22 here:

http://www.nsxprime.com/forum/showt...ssion-Fluid!?p=1686530&viewfull=1#post1686530

 

[winreboot]

Good info!
Is the Honda MTF silver bottle with white cap part number 08798-9031 and how many bottles go in to the gear box?

Thanks,

 

[joboo]

I've heard good things about the Amsoil MTF, but has anyone tried the Torco MTF?

 

[davidf]

The additives in synchromesh could cause the LSD clutch plates to slip excessively and make the diff act more like an open diff.

Could I add friction additive. We have small bottles of this for the GM and Ford limited slip diff's.

 

[stuntman]

Could I add friction additive. We have small bottles of this for the GM and Ford limited slip diff's.

Friction modifiers reduce friction for clutch type differentials that are aggressive and need to slip more. It will make the problem worse.

 

[Blackhorse06]

OK,now I am thoroughly confused. I was all set and convinced that Synchromesh was the end all/be all. There are even post of some Acura dealerships offering this stuff? I would be curious as to what Master Yoda...er I mean LarryB might have to say on this issue.

 

[davidf]

Great post Honcho and thank you for the elightenment. Guess I'll swing by Honda tomorrow morn. If someone will refresh my memory, 2 qts? FWIW, I did remove the small filter to clean 2 years back and she was clean as could be.:wink:

 

[GT-N]

GM Synchro Mesh works best for me.

 

[Honcho]

Good info!
Is the Honda MTF silver bottle with white cap part number 08798-9031 and how many bottles go in to the gear box?

Thanks,

I think it is about 2.5 bottles- you fill until it is dripping out of the fill hole.

I've heard good things about the Amsoil MTF, but has anyone tried the Torco MTF?

I believe Amsoil specifically says not to use their fluid in wet clutch type differentials.

Friction modifiers reduce friction for clutch type differentials that are aggressive and need to slip more. It will make the problem worse.

+1 yep.

Great post Honcho and thank you for the elightenment. Guess I'll swing by Honda tomorrow morn. If someone will refresh my memory, 2 qts? FWIW, I did remove the small filter to clean 2 years back and she was clean as could be.:wink:

See above- I think slightly more than 2 bottles.

 

[BATMANs]

They do. It is a wet clutch type. 95+ use a helical type. NSX-R uses a wet clutch type with increased preload.

What does the 93 NSX have for a LSD?

I've got 75k~ miles with Amsoil Syncromesh on the original tranny. It's only been changed once as of now.

I just got off the phone with http://www.torcousa.com/torco_product/rtf.html and they said that RTF and the Ford Type F friction modifier (not the GM one) is what their street and race customers use with great success.

- - - Updated - - -

The additives in synchromesh could cause the LSD clutch plates to slip excessively and make the diff act more like an open diff.

Would that cause permanent damage to the LSD?

- - - Updated - - -

I've heard good things about the Amsoil MTF, but has anyone tried the Torco MTF?

I might try this next. They use higher quality base stock than Amsoil in their RTF, which has a blend of Group 4 and 5 (this is the highest level oil base stock group that is used in turbine engines and is so dam expensive that u won't see a 100% group 5 oil).

Torco was selected by the US military to power their UAV.

I have Torco (after trying out GM OEM, Amsoil, etc.) in my GTO's LSD and it made a huge difference in eliminating the LSD chatter.

 

[sylcurt]

So, in reading these tranny threads, I am getting more and more confused, especially since I really don't understand the functions and needs of the oil other than basic lubrication. When a first bought my NSX, I had no idea when the tranny fluid had been last changed, so I went to my local Honda dealer (no Acura close) and bought 3 quarts of their MTF Fluid (I assume it was their basic run of the mill Honda MTF Fluid...as it did not have a white cap) The tranny before the change was a bit stiff, and notchy from 1st to 2nd to 2nd to 3rd. After the change it was exactly the same.

So then I drove it for about 1000 miles, and happened to be in an auto performance store , and saw their Royal Purple MTF so I bought 3 quarts of that, and changed it....it was immediately better in terms of reducing (not eliminating) the previously mentioned notchiness, and was much less stiff, and smoother overall. Truly, the car was easier to drive, no question. I have had the RP in there now for about 4000 miles (3 years) and car is shifting and running great....still smooth and buttery, and very little notchiness, if at all. (Maybe I am just a better shifter now ?) But, I am now reading all this about Don't use Royal Purple, and it has me concerned. So of course, it again comes to the Acura White Cap?....the GM Synchro /GM FM cocktail ?....or the Amsoil MTF. (I run Amsoil in my engine and find it is verygood...although I can;t honestly say how I would know if it was not good)

so some questions I am hoping someone can chime in on to clarify for me:

1) The GM cocktail is widely agreed it makes things smoother and less notchy, but with the possiblity of adverse long term wear effects on tranny...correct?

2) Is the GM cocktail synthetic? Is the Acura White cap synthetic?

3) the knock on the GM cocktail is that it is too thin, so could a person develop a new "cocktail" that has maybe one part GM FM, 1 part GM Synchro, and 1 part Acura white cap? or is this essentially defeating the purpose of the FM?

4) Do we have wet clutch applications in our cars? (I am all OEM, don't track....occasional use, the occasional longer freeway ride , driven only in spring/summer months)
The reason I ask is that on the Amsoil site, it says not for use in engines, or wet clutch applications....yet it says it is recommended by many manufacturers, including Honda. Seems kind of
contradictory if we have wet clutch applications in the NSX? Note that it says it is a direct product replacement for the GM MTF fluids?

5) I am actually leaning mostly to an all Amsoil application of their 5W -30 MTF....however, I see they also offer another "heavy duty" type of MTF, for higher horsepower engines, however, I will assume that it is not going to work for us....it was SAE 75-90 or something?

6) if we are "mixing cocktails" anyway, why not develop the best of all worlds....ie: 1 part GM FM, 1 part Honda white Cap, 1 part Amsoil? (shaken or stirred...just kidding) but would this be horribly bad to mix brands? I guess that is why I am wondering which is synthetic and which is not....I can see mixing all synthetics, but not organic and synthetic.

I guess my wish list is to keep the same buttery smooth shifting and almost no notchiness I have now, but not endanger the future reliability of my tranny...I plan to keep this car a long time...or at least until I can afford a second gen NSX....(which may be a VERY long time)

I have read over so many posts and different threads on this tranny fluid issue...and its almost like there is a FORD vs GM, or Coke vs Pepsi dialogue...so is it really just personal opinion, or is there any actual fact or technical logic to support using (or not using) a given brand....

Thanks guys....I'm ready to pull the trigger on Amsoil unless there is a reason I shouldn't....such as mixing in something with it for "flavor"....

link to 5W30 stuff
http://www.worldsbestoil.ca/Synchromesh-Transmission-Fluid-MTF.php

link to high performance stuff
http://www.worldsbestoil.ca/GL4-Synthetic-Manual-Transmission-Lube.php

 

[USAFguy22]

I believe 91-94 have wet clutch type difs, 95+ have Torsen style difs

 

[KooLaid]

I went from 2nd gear grinds and notchy shifting to butta when I put in full GM FM, no cocktail just all the good stuff. Ran it for 50,000+ miles without a single problem

 

[shawn110975]

well I think for 36 bucks its worth a try right, if people dont like it switch back. its not gonna hurt anything

 

[Honcho]

so some questions I am hoping someone can chime in on to clarify for me:

1) The GM cocktail is widely agreed it makes things smoother and less notchy, but with the possiblity of adverse long term wear effects on tranny...correct?

Correct. The friction modifiers in the GM fluid improve the engagement of the shift arms/selectors and synchros on your mainshaft and countershaft. But, they may cause adverse effects on your differential, which also uses friction between clutch discs to engage the locking function.

2) Is the GM cocktail synthetic? Is the Acura White cap synthetic?

Unknown. Anecdotally, I have heard the White Cap is a synth blend.

3) the knock on the GM cocktail is that it is too thin, so could a person develop a new "cocktail" that has maybe one part GM FM, 1 part GM Synchro, and 1 part Acura white cap? or is this essentially defeating the purpose of the FM?

You could, but it would be trial and error testing on a very expensive transmission.

4) Do we have wet clutch applications in our cars? (I am all OEM, don't track....occasional use, the occasional longer freeway ride , driven only in spring/summer months)
The reason I ask is that on the Amsoil site, it says not for use in engines, or wet clutch applications....yet it says it is recommended by many manufacturers, including Honda. Seems kind of
contradictory if we have wet clutch applications in the NSX? Note that it says it is a direct product replacement for the GM MTF fluids?

1991-1994 NSX 5-speed manual cars have a wet clutch type differential. 1995-2005 NSX 5 and 6-speed cars have a helical or "torsen" type differential. The 1991-1994 NSX differential is different than most other Honda MT cars, so I suspect the "Honda recommends" probably applies to the Civic/Accord/Integra product line instead, which is what 99.9% of potential customers are probably shopping. Because you do not track your car, the GM stuff probably is fine since you do not really need limited slip functionality. Moreover, it likely would take tens of thousands of miles for any premature wear to show up in the differential clutch pack. So, even though you may damage your differential, your practical application means it doesn't matter. The car will still work, but your rear wheels will not lock on acceleration anymore or as much. You probably won't notice it.

5) I am actually leaning mostly to an all Amsoil application of their 5W -30 MTF....however, I see they also offer another "heavy duty" type of MTF, for higher horsepower engines, however, I will assume that it is not going to work for us....it was SAE 75-90 or something?

Honda originally specified 5W-30 motor oil for the trans in 1991. The MTF is a much improved formula designed for the wet clutch diff, but it is still based on that weight oil. If you do go Amsoil, I would stick with the 5 weight stuff.

6) if we are "mixing cocktails" anyway, why not develop the best of all worlds....ie: 1 part GM FM, 1 part Honda white Cap, 1 part Amsoil? (shaken or stirred...just kidding) but would this be horribly bad to mix brands? I guess that is why I am wondering which is synthetic and which is not....I can see mixing all synthetics, but not organic and synthetic.

See # 3 above.

I guess my wish list is to keep the same buttery smooth shifting and almost no notchiness I have now, but not endanger the future reliability of my tranny...I plan to keep this car a long time...or at least until I can afford a second gen NSX....(which may be a VERY long time)

I have read over so many posts and different threads on this tranny fluid issue...and its almost like there is a FORD vs GM, or Coke vs Pepsi dialogue...so is it really just personal opinion, or is there any actual fact or technical logic to support using (or not using) a given brand....

Bottom line is this: your transmission is lubricated and cooled using a pressurized and filtered oil system that also lubricates the differential clutch pack. This is different than most passenger cars. Honda designed the system and tested it over many cycles using many different oils. To date, they have concluded two oils are safe to use in the NSX transmission: 5W30 motor oil and Honda MTF. They did not test any other oil. The issue in all these threads is not that aftermarket oils will damage your transmission (except for the Amsoil, which specifically says NOT to use in our type of trans), but that we simply don't know what the effect will be because Honda never tested it. Running it for 50,000 miles and saying my trans shifts great is not testing. That differential clutch pack may be completely shot for all they know. The only way to test for sure is to open up and inspect the trans pre-oil. Then run it for a long time. Then, open the trans again and check for wear/damage. I guarantee you none of the aftermarket companies have done this with a 1991-1994 NSX trans. The only company who did is Honda. Dozens of times.

Accordingly, all this is is a risk proposition. If you put anything else but the two oils above in your NSX, you don't know what it will do to your trans. Maybe it will be ok. Maybe it won't. If the nice shifting action of the Synchromesh is valuable to you, then perhaps it is worth taking the risk. For me it isn't. I track my car and have seen my trans opened up. My NSX has had nothing but the Honda MTF and the internals showed no signs of wear over 80,000+ miles. That's good enough for me, even if I have to wait a few minutes for the trans to warm up before I get the "butter" shifts. YMMV.

Hope this helps clear it up.

 

[cparsons]

When you guys say "New Honda MTF Whitecap", is that referring to this? Genuine Honda Fluid 08798-9031 Manual Transmission Fluid

Edit: fixed the link

 

[Tangoman]

When you guys say "New Honda MTF Whitecap", is that referring to this? Genuine Honda Fluid 08798-9031 Manual Transmission Fluid

Yes sir. That's the one.

 

[Mac Attack]

Accordingly, all this is is a risk proposition. If you put anything else but the two oils above in your NSX, you don't know what it will do to your trans. Maybe it will be ok. Maybe it won't. If the nice shifting action of the Synchromesh is valuable to you, then perhaps it is worth taking the risk. For me it isn't. I track my car and have seen my trans opened up. My NSX has had nothing but the Honda MTF and the internals showed no signs of wear over 80,000+ miles. That's good enough for me, even if I have to wait a few minutes for the trans to warm up before I get the "butter" shifts. YMMV.

Hope this helps clear it up.

For a data point, I had my transmission opened about nine years ago to replace the transmission case half (in snap-ring range) and replace a few synchros while I was in there. The transmission had 65k miles on it. When it was put back together, I used Honda MTF. I doubt it was the white cap stuff. I drove it for about 2k miles and didn't like the notchiness in 1st and 2nd, so I switched to the GM synchromesh with 1qt FM. The GM parts guy told me "All the MT Honda owners come in to buy it." :wink:

No difference on LSD feel with the GM FM blend. Then I switched over to the Amsoil MTF after three years on the GM blend (even though Amsoil said it wasn't recommended). Ran that for about 3.5 years and noticed that the LSD felt slightly more aggressive (which I liked). Fast forward to now, and my car has been in a rebuild state for the past 1.5 years all apart. The transmission was opened up, and all synchros looked new. Clutch pack discs were measured and were within spec. It was reassembled according to Type R specs. So, after seven years and 70k miles with GM FM blend and Amsoil MTF, the transmission was in perfect shape.

Honda does not know all and they are slow to react to market and new product offerings. This is for good reason - to cover themselves. Bottom line is do your own research and be prepared for the consequences.

When I eventually put my engine and transmission back in, I've already purchased the new Honda MTF white cap stuff to try in it. Why not?

Good luck.

Dave

 

[BATMANs]

.......My NSX has had nothing but the Honda MTF and the internals showed no signs of wear over 80,000+ miles. That's good enough for me, even if I have to wait a few minutes for the trans to warm up before I get the "butter" shifts....

I've driven a couple of NSX's with lessor miles that run the white cap. It's nothing close to the Amsoil experience. warm or cold

- - - Updated - - -

...... Then I switched over to the Amsoil MTF after three years on the GM blend (even though Amsoil said it wasn't recommended). Ran that for about 3.5 years and noticed that the LSD felt slightly more aggressive (which I liked). Fast forward to now, and my car has been in a rebuild state for the past 1.5 years all apart. The transmission was opened up, and all synchros looked new. Clutch pack discs were measured and were within spec. It was reassembled according to Type R specs. So, after seven years and 70k miles with GM FM blend and Amsoil MTF, the transmission was in perfect shape.

Honda does not know all and they are slow to react to market and new product offerings. This is for good reason - to cover themselves. Bottom line is do your own research and be prepared for the consequences.

When I eventually put my engine and transmission back in, I've already purchased the new Honda MTF white cap stuff to try in it. Why not?

Good luck.

Dave

I too noticed that the tranny with 120k miles had exhibited a more aggressive LSD. Loved it. Felt like it was mechanically modded.

I too agree that OEM are sllllooooowwww to react to the aftermarket.

Case in point:

Mazda said that synthetics should NEVER EVER be used in ANY rotary engines.

Well, between the FC & FD RX7s I ran over 400k miles with Redline 20w50.

My FC had the original engine that ran to 185k miles. It finally died when the thermostat failed and over heated the engine. That made me look for the FD, otherwise I would have just kept on driving it.

The FD engine was replaced a few times from well, we all know this - detonation. Anything that was lubrication related parts were in much better condition than parts that ran mineral oil. I sold the FD with 250k miles. I miss that car.

Now with the NSX and all of my car and truck I now run Amsoil (everywhere else) and Pennzoil Ultra (engine only). Like you I'm one of the few people that ACTUALLY opened up the engine to have it fully inspected and was told by my my engine builder that the parts related to being oiled are virtually brand new.

 

[A.S. Motorsport]

To date, they have concluded two oils are safe to use in the NSX transmission: 5W30 motor oil and Honda MTF. They did not test any other oil. The issue in all these threads is not that aftermarket oils will damage your transmission

First of all very nice post by Honcho,

I'd like to add to that if you check "old" service manuals it says, 5w-30, 10w40 and 20w40
The last being fairly thick and i'd not do that.

Later on the switched to the superior Honda MTF.
Now I've always sticked with Honda oils as I've had great experience over the years.

I'm very interested in the MTF vs Synchro discussion i know of the qualities of synchro but I am concerned with clutch wear in the differential.

 

[sylcurt]

I just want to Thank Honcho for the great detail in replying to my post, and expressing his opinions, along with the others who have chimed in.

I totally get how this becomes a bit of a risk proposition, but if the "risk" of a premature worn out tranny after say 200,00 miles is the effect of having a smoother shifting and more pleasurable driving experience, I think I would be willing to take it, because at my 3000 miles a year (maybe) thats a long time away....

to clarify, mine shifts well, only a bit notchy from 2nd to 3rd when I had the Honda fluid in it...since RP, its all very smooth, drives very easy...I am just thinking I want to get it out based on several opinins I've read here. So its now down to Amsoil vs. Honda MTF white cap vs. GM cocktail....I'm almost tempted to try the Cocktail now, since so many have raved about it...ah, I don't know...maybe I need to flip a coin...lol
Thanks to all in any event...at least I have a better understanding of things.

 

[BATMANs]

....I totally get how this becomes a bit of a risk proposition, but if the "risk" of a premature worn out tranny after say 200,00 miles is the effect of having a smoother shifting and more pleasurable driving experience, I think I would be willing to take it, because at my 3000 miles a year (maybe) thats a long time away....

It's a "risk" proposition based on unproven assumptions.

If anything I think Mac Attack number of miles and actually opening up the tranny to confirm that it's not an issue should be suffice to quench aforementioned concerns and prejudice.

 

[bonhamsurf]

Ok, so here's my question, situation.
I have a 1991 with a NSX-R 4.23 Final Drive and also NSX-R Upgraded Differential. I'm running a one-off Exedy Twin Disc that was taken out of Cody Loveland's 2012 Pike's Peak Race car. I'm currently making no less than 581rwhp. When I did the engine, turbo and clutch, I started using Redline MTL. Now, when the clutch is hot, it grinds for a moment going into 3rd gear, but only when it's hot like after I put the car into boost and push it for a moment.
So, I'm going to flush the tranny and try either
1. OEM Acura MTL from my local Acura dealer.
or
2. Torco MTF and possibly with Torco Limited Slip Friction Modifier.

After reading this

Friction modifiers reduce friction for clutch type differentials that are aggressive and need to slip more. It will make the problem worse.

I'm not too sure I should add the Torco Limited Slip Friction Modifier.

Any input? If I do add the Torco Limited Slip Friction Modifier, how much should I add? THey come in 4oz bottles.

Or should I not add it at all? Any other input is appreciated. Thanks!

 

[Old Guy]

Just a note for those who believe that later versions of the NSX have a Torsen type differential that will not be affected by friction modifiers. The 1997 service manual shows the NSX differential with a clutch pack and nary a worm gear in sight (Torsens are chock full of worm gears and don't have clutch packs). My 2000 supplement to the 1997 service manual does not list any changes to the differential so we can assume that up to 2000 the NSX had a clutch style LSD. In my opinion, the use of appropriate transmission oils with friction modifiers is not going to result in damage to the transmission and may or may not result in any lasting change to the LSD function of the differential (keeping in mind that the transmission and differential share the same oil); however, as Stuntman notes, its likely going to render the LSD to a non functioning condition (i.e converting it to a conventional open differential). If you spend most of your time driving in straight lines (most of us do), don't hammer the throttle in tight radius corners and don't drive in the snow or on ice or other reduced traction surfaces, you may never notice the loss of the LSD function. You shift gears a few hundred (thousand?) times a month and may never engage the limited slip function in the differential in that same period. If you are not taking your car to the track, the trade off for smoother shifting with the friction modified lubricants may be worth it. Your choice! You may or may not be able to recover the LSD function by draining out the friction modified oil and replacing with conventional transmission lubricant. That would depend on whether the friction modifiers tend to bind to the clutch surfaces. Your risk!