Best Manual Transmission Oil :-)

[Setright]

Okay, so I have been driving with Castrol TAF-X 75W-90 for over 3000 miles now, the shift has improved considerably with the miles since the oil change.

There was a slight improvement initially, but as the oil has conditioned the surface of the synchro rings, the shift has really improved quite a lot. Slowing down to walking pace it will slip into first without any need for double de-clutch, and no sign of the clonk of previous oils. The dreaded 2nd to 3rd upshift is smooth too!

I would strongly recommend trying this oil the next time any of you change tranny oil. Especially if you feel Redline let you down :-)

 

List of others tried:

Mobil

Castrol

Redline

Quakerstate

[Nug]

Setright,

 

You seem to back this stuff up pretty strongly, so I have decided to try it. Of course, TAF-X isn't sold in the US. I did some research, and found that is IS sold in the US, but under a different name. The following is from Hondatech forums...

 

 

 

Oct 1, 2002 - 23:46 - From: Doug

Title: Castrol TAF-X in the USA

Message: Here is the response to the inquiry I sent to Castrol USA about where to get Castrol TAF-X in the USA: "Castrol TAF-X 75W-90 GL-4 gear oil is made in the U.K. and sold only in Europe. However, the equivalent in the U.S. is Syntorq LT. Having said that, Syntorq LT SAE 75W-85, API GL -4 is a premium high performance, synthetic gear lubricant for synchronized manual transmissions. The all new "clean slate" approach enables Syntorq LT to provide consistent performance and durability under the most severe operating conditions due to its unique polymer free formula. It has been designed primarily as a problem solving gear lubricant for manual transmissions to provide reduced gearshift effort at low temperatures. Syntorq LT is available through General Motors (Part #12346190) and Chrysler (Part #4637579) dealerships. Please contact your local dealership." the best deal is at gmpartsdirect.

 

 

So i ordered some from gmparts direct. A little over $55 including shipping for 4 quarts. I'm assuming you can buy it over the counter, but I have no idea where the Chevy dealers are in the area, besides I didn't feel like driving.

 

When i put it in, I'll post results. Right now I'm getting a little bit of scrape downshifting into first.

 

IByoushouldn'tshiftintofirstwiththecarstillmoving.

 

Whatever.

 

Calebz-this is what I was talking about. My bad.

[DerFahrer]

My opinion: put the cheapest, crappiest 80W90 gear oil you possibly can in a Subie tranny, and don't slam through the gears, it's unnecessary.

[Setright]

I trust you will find that is money well spent, Snotrocket :-)

 

Subyluvr, I respect your approach. I just like to pour lots of money into my cars, regardless of whether I can afford to! Dino oil makes cold shifts very baulky. Frost and city driving, means that the gearbox takes a long time to warm up... Synthetics have a clear advantage in this discipline.

 

As for when to shift into what gear, I will make my own decisions ;-)

 

 

(Although that pesky rev-limiter always cuts things short!)

[gbhrps]

For years now the guys and gals with 90-96 Nissan 300ZX's have been religiously using Redline MT90. There are hundreds of excited persons who had shifting/grinding problems that were corrected or substantially improved using it. Check out the TwinTurbo.net forums and search for transmissions, gear oil, etc. to check it out. I haven't noticed any difference thus far in my own 90 300ZX, as I only use it as a toy for maybe 2000 km a year, and the car is so low mileage that there is no wear yet in the gear set.

[Panthasoccer4]

Correct me if im wrong, but the GM oil is gl-4. I thought we all had to use gl-5??? For an amateur like myself, some explain the difference between the 2 categories. My tranny is grinding like mad from 2-1 where i have to be completely stopped. But i dunno if i can part with 45 bucks for 3 quarts.

[wrcRabbit]

Recently, I've put Royal Purple into my 03 wrx's tranny...it is much easyer now to put it into 1st when rolling to a stop...also slides into reverse with out having to play with it...is alittle spendy but I feel well worth it

[DerFahrer]

I just like to pour lots of money into my cars, regardless of whether I can afford to!

Trust me, I do too. The motor mounts I put on my Legacy were brand-new liquid-filled OEM mounts from the dealer for a mere $330 I need to finish up my R134 A/C conversion on my Legacy, and I'm doing that by putting in a new compressor, and replacing the pressure lines with R134-style fittings already on it, and completing it with an actual Subaru R134 sticker to replace the R12 one on my rad support I could go on...

 

I am obsessive in the way I invest money in my cars, but I cheap out on spark plugs and gear oil, because the cheapest forms of these work best IMO...

 

But what works best for you Setright, go with it

[Setright]

Hats off, Subyluvr!

 

 

By the way, do those engine mounts work the business?

[Nug]

I've recently put Redline MT-90 in my Tacoma to help a cold-shifting problem. It works great.

[fnlyfnd]

I used mt90 and toped it off with syncromesh back in dec or jan....

Cold shifts always sucked and clunked, over the summer the shifting was great, now that its getting colder the shifts are getting worse, again. So I am switching to uncle scottys cocktail. I know a lot of u are not fond of nasioc, but this guy has been running it for 3 years with no problems, and hundreds of people on that board use it and love it. Some oldschool people over there have used it also and saw improvement. I will list the cocktail ingredients:

1 qt Redline lightweight shockproof

1 qt penzoil Syncromesh

1.x qt castrol HypoyC 80w-90

 

You can order everything from amazon. When you order it, you'll see that the related items are all listed, and they are the other componetns of the mixture. Like I said I haven't tried it but give me a month.

[cookie]

Oil sure can make a difference in a tranny as well as an engine. I was whineing about my tranny being the next thing out on my Subaru about 40,000 miles ago and had the tranny oil changed. It cut noise about 50% when going for original fill with about 90,000 miles on it to new oil. this was nothing spechial, just dealer stock.

Setright was one of the folks who told me the 5 speed might whine on forever and right now it looks like it might.

All modern oils are very good but some are just a bit better than others for particular purposes.

I've noticed improved shifting on my BMW when changing from Redline to Specialty Lubes MTF Glide.

Recently trying Havoline in my Forester seems to have cut piston slap. Oil is somewhat cheap to experiment with.

[rweddy]

I used mt90 and toped it off with syncromesh back in dec or jan....

Cold shifts always sucked and clunked, over the summer the shifting was great, now that its getting colder the shifts are getting worse, again. So I am switching to uncle scottys cocktail. I know a lot of u are not fond of nasioc, but this guy has been running it for 3 years with no problems, and hundreds of people on that board use it and love it. Some oldschool people over there have used it also and saw improvement. I will list the cocktail ingredients:

1 qt Redline lightweight shockproof

1 qt penzoil Syncromesh

1.x qt castrol HypoyC 80w-90

 

You can order everything from amazon. When you order it, you'll see that the related items are all listed, and they are the other componetns of the mixture. Like I said I haven't tried it but give me a month.

You cannot/should not use MT90 in a subaru since the tranny and diff share the same fluid.

 

Use 75W90NS, I run this in all my subarus and it works great.

[edrach]

Sorry to disagree with your diss of Redline, but I have to recommend the Redline 75W-90NS which is what they suggest for "older" transmissions with synchro problems. When I bought our '91 Legacy wagon it came with a significant "crunch" when shifting into 2nd and down into 1st. I changed the oil when I bought the Legacy and found that the "crunch" disappeared in the next 3 to 6 months. Being a bit skeptical, there was always the possibility that I was compensating for the defect in the synchros and that it wasn't the oil at all. Since then I've put 75K miles on the car and the transmission is shifting just fine (due for another oil change in the next year of so). More recently, I bought a '94 Impreza sedan with a much more definite "crunch" shifting in the lower gears. I only use the Impreza for rallycross and while any of our daily driver's is out of service. I changed the transmission oil shortly after I bought it and again used the Redline NS oil. In the few miles I've driven the car (around 5K) the "crunch" is definitely diminished and I have to purposely rush the shift to see even a hint of it. This Impreza comes with a "short shifter" installed which likely takes its toll on the synchros. After two good successes with the Redline I see no reason to try anything else. The cost of the Redline (4 quarts at less than $10 per quart) for 75K to 100K is really insignificant. Information can be found at Redline's website: http://www.redlineoil.com/products_gearlubricants.asp?productID=38&subCategoryID=15&categoryID=6

[rweddy]

Sorry to disagree with your diss of Redline, but I have to recommend the Redline 75W-90NS which is what they suggest for "older" transmissions with synchro problems. When I bought our '91 Legacy wagon it came with a significant "crunch" when shifting into 2nd and down into 1st. I changed the oil when I bought the Legacy and found that the "crunch" disappeared in the next 3 to 6 months. Being a bit skeptical, there was always the possibility that I was compensating for the defect in the synchros and that it wasn't the oil at all. Since then I've put 75K miles on the car and the transmission is shifting just fine (due for another oil change in the next year of so). More recently, I bought a '94 Impreza sedan with a much more definite "crunch" shifting in the lower gears. I only use the Impreza for rallycross and while any of our daily driver's is out of service. I changed the transmission oil shortly after I bought it and again used the Redline NS oil. In the few miles I've driven the car (around 5K) the "crunch" is definitely diminished and I have to purposely rush the shift to see even a hint of it. This Impreza comes with a "short shifter" installed which likely takes its toll on the synchros. After two good successes with the Redline I see no reason to try anything else. The cost of the Redline (4 quarts at less than $10 per quart) for 75K to 100K is really insignificant. Information can be found at Redline's website: http://www.redlineoil.com/products_gearlubricants.asp?productID=38&subCategoryID=15&categoryID=6

 

I think many use the wrong type fluid for Subaurs.

My Redline dealer has told me story after story of Subaru owners who were told then need new trannys only to run 75W-90NS and fix their troubles.

 

I have been a bit fan of Redline for year, has fixed several of my roos shifting issue from way back.

[subyboy]

rweddy, what you say is strange.

I talked to a Redline technician to make sure MT-90 was OK for my '91 Legacy AWD and he assured me it was fine, even though it's only GL-4. He said Redline oils are so superior that their GL-4 is superior to cheap GL-5. Of course he works for Redline so he'll say that but he seemed genuine.

Just a thought...

Cheers

[rweddy]

rweddy, what you say is strange.

I talked to a Redline technician to make sure MT-90 was OK for my '91 Legacy AWD and he assured me it was fine, even though it's only GL-4. He said Redline oils are so superior that their GL-4 is superior to cheap GL-5. Of course he works for Redline so he'll say that but he seemed genuine.

Just a thought...

Cheers

I think they are messing with you since you are not from the states!

 

Here is the email back from redline on this topic.

 

 

 

>Request Type : Technical Request

>Message : Hello

>

>I am trying to figure out what type fluid I should run in my vehicle

>manual transmissions. I have used your MT-90 in multiple vehicles

>with great success.

>

>My question revolves around running a GL4 transmission fluid in a

>Subaru where the transmission and front differential share the fluid.

>

>The factory recommends using GL5 fluid but I have run GL4 in most

>all my manual box and the difference between running GL5 and GL4 is

>night and day, with the GL4 working sooo much better.

>

>What type of fluid would you recommend I run in a Subaru with shared

>transmission and front differential?

>

>Thanks

 

Richard,

 

In your Subaru transaxle where the GL-5 gear lube is called for I

would recommend the 75W90NS, I would expect the shiftability to be

close to the MT-90. The NS fluids have no friction modifier so are

not to slippery for the synchros the problem with most GL-5 gear

oils. The 75W90 would be suitable for the rear differential.

 

Regards, Dave

Red Line Oil

[Fairtax4me]

I've found some info about the differences in API oil grading specifications.

This guys english is a bit dodgy, but you should be able to make out the basic point, that the main differences between GL-4 and GL-5 are the amount of antiscuffing additives, not necessarily the additives themselves.

 

Dear Mr. Hughes,

Let me offer to you a small excursus in area of transmission oils.

API classification subdivides all transmission oils into 6 classes:

API GL-1 - oils for light conditions. They will consist of base oils without additives. Sometimes they contain small amounts of antioxidizing additives, corrosion inhibitors, depresants and antifoam additives. API GL-1 oils design for spiral-bevel, worm gears and manual transmissions without synchronizers of trucks and farming machines.

API GL-2 - oils for moderate conditions. They contain antiwear additives. They design for worm gears of vehicles. The oils recommend to lubrication of transmissions of tractors and farming machines.

API GL-3 - oils for moderate conditions. The oils are containing up to 2.7 % antiwear additives. They design for lubricating bevel and other gears of trucks. Not recommended for hypoid gears.

API GL-4 - oils for operating in different conditions - from light to heavy. They contain 4.0 % of effective antiscuffing additives. The oils are designs for bevel and hypoid gears which have small displacement of axes, for gearboxes of trucks, for units of axles. These oils are recommended for not synchronized gearboxes of US trucks, tractors and buses, for main and other gears of all vehicles. Now these oils are the basic for the synchronized gearboxes, especial in Europe.

API GL-5 - oils for the most loaded gears, working in severe conditions. They contains up to 6.5 % effective antiscuffing additives. The general applications of oils this class - the hypoid gears having significant displacement of axes. They recommended as universal oils to all other units of mechanical transmission (except gearboxes). The oils which have special approval of vehicle manufacturers can to use for synchronized manual gearboxes only. API GL-5 oils can be used for limited slip differentials if they correspond to requirements of specification MIL-L-2105D or ZF TE-ML-05. In this case the designation of class will be another, for example API GL-5+ or API GL-5 LS

API GL-6 - These oils for the most loaded gears working in very heavy conditions (high speeds of sliding and significant shock loadings). They contain up to 10 % high performance antiscuffing additives. They designed for hypoid gears with significant displacement of axes. Now class API GL-6 is not applied any more as it is considered, that class API GL-5 well enough meets the most severe requirements.

 

As almost all Transmission Oils have S-P compounds (antiwear or antiscuffing additives) they affect on parts of transmission units from yellow metals. This affect is some problem at use the transmission oils in different applications. Often we can see the results of misusing these oils. For solution problem were advise the antiwear and antiscuffing additive from inorganic borate compounds which no affect on yellow metals. The overall level of these additives meet API GL-5 but as these additives not attack yellow metals the performances such oil are meet API GL-1. The use of inorganic borate compounds allows recommend such oils for all applications - from API GL-1 to API GL-5. It looks like Universal Transmission Oil.

Excuse me for long lecture, but I hope it will useful for you.

 

 

Mikhail

 

Found that info here: http://forums.noria.com/eve/forums/a/tpc/f/826604995/m/169106369

[hustle]

And that note... My 91 Legacy I just purchased has crazy dirty tranny fluid and I need to change it real quick like, but was wondering if it would help to rinse it out with a change and then change it again shortly after? Or should I not bother?

[Fairtax4me]

Yes, repeated changes will help to essentially "flush out" dirt and grime that may be built up in the transmission. Use the cheap $5 a gallon 80w90 stuff they sell at Autozone for that. Change it, drive it a little while (like a week) then change it again. Do that several times lengthening the interval between changes each time.

[forester2002s]

Yes, repeated changes will help to essentially "flush out" dirt and grime that may be built up in the transmission. Use the cheap $5 a gallon 80w90 stuff they sell at Autozone for that. Change it, drive it a little while (like a week) then change it again. Do that several times lengthening the interval between changes each time.

I agree.

And, if the drain plug has a magnet, make sure to clean off all the furry stuff from the magnet.

 

And, for new car owners: My practice is to change the transmission and diff oils soon after the gears have been run-in (within a few 1000 km), and after that at the recommended intervals.

From my industrial experience with gears, I know how important clean oil is to the longevity of gears.

[vpfalcon]

My 1993 Makes the winding sound in all the gears especially when I take my foot off the gas. It sounds like the car is in reverse. It is sometimes hard to get the engine revs in first gear, so it makes me look like an idiot in traffic jams, revving the engine and letting the clutch out . The car has a new clutch, a transmission shop guy says the tranny is toast. I changed the transmission oil (80 weight) but that didn't help much. I hate to spend a thousand on a transmission.

The car runs great after I get out of first, but it is a 93 with 180 thou on it. I guess I'll drive it and hope for the best. If anyone has had this same problem I would like to hear what was wrong with their car.

[Fairtax4me]

Not going into first gear when sitting still sounds more like a clutch problem. Usually when the clutch doesn't release properly. A seized pilot bearing can also cause the same problem, but try adjusting the clutch cable to bring the pedal up a little higher and see if that helps before condemning the transmission.

There's not much out there in the way of fluid that will help a worn first gear synchro. It can be dealt with though, you will just have to push the clutch pedal in and hold it for a few seconds before trying to engage the gear.

 

 

Edit:

I'm actually glad this thread was resurrected... again. I had consistent shifting issues that varied with transmission oil temperature. On plain off the shelf 80w90 I had hard/stiff shifting when cold and a definite thud when going into second gear. After switching to Amsoil synthetic 75w90 the second gear and cold shifting issues went away, however I developed a crunch going into third when the trans was warm. I did not get a chance to see if another fluid would have corrected the third gear shift.

I have replaced that transmission, due to a worn main shaft roller bearing, with one of lower mileage. The "new" transmission has the same shifting issues, but both are present with standard 80w90 gear oil.

Reading that the OP had success with a GL-4 grade oil, I think I may try out a GL-4 synthetic oil of some type, just to see what it will do.

I'm still not entirely convinced that a GL4 fluid is safe for use with the front differential. But I can send in a sample of oil for testing after every 7500 miles or so to look for wear patterns of the internals of the trans. The differential ring gear and pinion gear are made of a different type of steel than the other gears in the trans, same with the various types of bearings. So fluid analysis should detect the different grades and types of metals as the components wear.

Edited October 13, 2011 by Fairtax4me

[Crazyeights]

My opinion only, regular NON-SYNTHETIC 75w-90 with some Rislone added for the synchros. Seems to work the best for me. YMMV

[Loyale 2.7 Turbo]

I've tested many Gearbox / Differential Oils in the Past, in many cars and in my Own experience with those, Specially with Older Gearboxes or Diffs, The Best oil is the one Reinforced with Molybdene:

 

Somehow is the Same Black Grease Base that we use on C.V. Joints:

 

 

 

(Motul 31721L Gearbox 80W-90 Molybdenum Bisulphide

-MoS2- Reinforced Extreme Pressure Gearbox and Differential Lubricant)

 

 

This Shiny Black Oil not only makes Quieter any old Gearbox, it also makes Easier Shifting.

 

Believe me, the Difference is Huge, I Run my Weberized Wagon's 5MT with it since around year 2000 (I usually Change it every three years), also I poured it onto many other Manual Cars with great results.

 

Kind Regards.