What to put in my '89 Prelude's MT?

[Gebo]

The original owner's manual says to use 10w-30 motor oil. Amsoil site says to use 10w-30 motor oil. Other owners are saying to use Honda MTF or GMsyncromesh. What should I use if I want to use the "best"?

 

[Quest]

Use Honda MTF if you can. Q.

 

[beast3300]

Call the dealer but I believe the Honda dealers would use the Honda stuff in it.

 

[4D-56]

Just recently changed MT oil in our Honda, used Amsoil 10W30, it shifts very nicely, has a nice positive feel to it. The Amsoil replaced some PYB 10W30. Will use more Amsoil next time.

 

[Cup of Joe]

I have used 75w-90 gear oil and 5w-30 in the same honda transmission, with no difference in performance. Motor oil will work fine, otherwise I would use synchromesh. My personally preference would be synchromesh.

 

[Smoky14]

Definitely go with Honda MTF. The 10-30 spec in 89 was a different oil than the SM you get today. When oil changed from, I think SE, it no longer worked well in manual trans thus the reason Honda started making a specific MTF.

 

[Lead Shoes]

I too have been trying to pin point what to use in my Honda transmission (S40). There is no real golden lube that will make every Honda transmission feel perfect, you will have to experiment for yourself, every transmission has worn differently, but as long as it is a 30 or 40 weight oil the transmission shouldn't die because of a certain fluid. Food for thought, the new Honda MTF they sell is nearly a 20 weight oil to try and wring out a little more MPG, which can cause shifting issues to appear in our older transmissions, if you can find the old spec Honda MTF grab it all. I had a fill of the old stuff, it was great, got the new stuff for my change last year and it was notchy and like sorting though a bag of coconuts. I have tried nearly every synchromesh product on the market, even the boutique synchromesh, but not RP, currently Pennzoil syncromesh is giving me the best results I have had so far. I'm curious stro was it just Amsoil XL?

 

[Mr Nice]

Our 1998 Civic EX was run with SL rated Havoline Syn and it shifted just fine. Didn't the old Honda MTF thin out to 20 weight in less than 20K miles?

 

[WANG]

Originally Posted By: Brenden

Food for thought, the new Honda MTF they sell is nearly a 20 weight oil to try and wring out a little more MPG, which can cause shifting issues to appear in our older transmissions, if you can find the old spec Honda MTF grab it all. I had a fill of the old stuff, it was great, got the new stuff for my change last year and it was notchy and like sorting though a bag of coconuts. I have tried nearly every synchromesh product on the market, even the boutique synchromesh, but not RP, currently Pennzoil syncromesh is giving me the best results I have had so far.

I was going to point out that the current Honda MTF is pretty different from the MTF that was available in '97 from what I have read. The RP Synchromax has pretty similar specs to the "new" Honda MTF, there's a VOA on it here somewhere. If the "new" Honda MTF is backwards compatible, that would seem to open the door for a wide range of acceptable lubes. I just dumped RP Synchromax in the '97 Civic the other day, we'll see how that goes.

 

[4D-56]

Brenden.. the Amsoil used was the ATM 10W30, I know its one of those questionable "feel" things but I will say that I noticed a marked difference in gear shift compared to the Pennzoil. Even my wife noticed! Thought old now, its a great car to drive and had a renewed shift feel to it.

 

[Gebo]

I went to the dealership today and had them look up the current info for what to put in a 89 Prelude manual transmission 4WS Si in their official Honda service manual. SM said beforehand he knew it would be Honda MTF but the manual said either 10w-30 or 10w-40. I can't take it! You know Honda would recommend their own MTF if the could so why do they recommend regular motor oil... The Service Mgr then went to a 30 year service guy and he never put MTF in one of those transmissions. What's the deal? I have got to know the difference. I may not sleep until I can be quest for a chemical explanation can be given...

 

[MolaKule]

I would try the Redline MTL70W80 since it is a specific application Manual Transmission Lube (MTL). It has two base oils (GroupIV and V) with a high VI and a good additive system and just the right viscosity. Motor oils were specified during this period because there no decent MTL specific lubes available at the time.

 

[Gebo]

Originally Posted By: MolaKule

I would try the Redline MTL70W80 since it is a specific application Manual Transmission Lube (MTL). It has two base oils (GroupIV and V) with a high VI and a good additive system and just the right viscosity. Motor oils were specified during this period because there no decent MTL specific lubes available at the time.

Molakule, can you teach me a little? I trust your knowledge. Lots of my searches say to use GM Syncromesh with Friction Modifiers. They say it will smooth out all shifts but it seems some believe it will be smoothing out he shifts at the expense of wearing out the syncros??? Thanks!

 

[ltslimjim]

Any viscosity similar to 10w-30 or 10w-40, stated to use in M/Ts with friction modifiers are capable. I prefer Amsoil MTF in my app, I bet up in Virginia it'd be just fine especially during the winter.

 

[chevrofreak]

In my 86 Prelude we just ran tractor hydraulic fluid, since my dad had a drum of it. It ran fine. I'm not saying it was ideal, but it didn't cause any problems. I don't think the transmission was picky.

 

[MolaKule]

Quote:

Lots of my searches say to use GM Syncromesh with Friction Modifiers. They say it will smooth out all shifts but it seems some believe it will be smoothing out he shifts at the expense of wearing out the syncros???

All MT specific fluids have friction modifiers for synchro engagement and EP/AW additives. Occasionally you have to experiment with different fluids to find the one that provides the performance you expect. As I stated before, try the Redline MTL 70W80 first.

 

[Gebo]

Originally Posted By: MolaKule

Quote:

Lots of my searches say to use GM Syncromesh with Friction Modifiers. They say it will smooth out all shifts but it seems some believe it will be smoothing out he shifts at the expense of wearing out the syncros???

All MT specific fluids have friction modifiers for synchro engagement and EP/AW additives. Occasionally you have to experiment with different fluids to find the one that provides the performance you expect. As I stated before, try the Redline MTL 70W80 first.

Just placed my Red Line order from Amazon today. Currently using Honda MTF and am gonna switch out after 500 more miles to the Red Line. So in your opinion, I could use Honda MTF, Red Line MTL 70w80, GM Syncromesh or Amsoil Synchromesh without hurting or prematurely wearing out my Honda 5 Speed Transmission. And I should expect they will probably each perform a little bit differently. I need to experiment and find which ever performs the best in my particular situation. Somehow, I think you already know which will perform the best and don't want me wasting my money ;- ) Thank YOU!

 

[MolaKule]

Quote:

So in your opinion, I could use Honda MTF, Red Line MTL 70w80, GM Syncromesh or Amsoil Synchromesh without hurting or prematurely wearing out my Honda 5 Speed Transmission.

Yes.

Quote:

And I should expect they will probably each perform a little bit differently.

Absolutley, because each one form is formulated with slightly different additive packages and base oils.

 

[Gebo]

Molakule, I have tried the Honda, Amsoil and Red Line. You were (are) right. Red Line gives me the best feel. It seems just a little "thicker" than the Amsoil and my shifts are smoother. I'll let you know the final results in about 5,000 miles. Based on this, I'm gonna use some of the Red Line gear oil in my vehicles.