What is the best fluid to use in the TRANSAXLE (5 speed)

[Greywolf]

I want this to be a no BS thread, with real results


(please make sticky)

[ryanprins13]

I think you have been around here enough to see how controversial this subject always gets but i think to try and sum it up it doesnt matter which of these you use for daily driving, the transmission will never fail from an oil related issue with any of these as long as it never runs low and gets the fluid changed every 100k or something. If your racing or driving it hard the order sor of is:
1. 20w50 synthetic motorbike oil.
2. 80w90 syn gear oil rated GL-4. (Most GL-5 rated gear oils are more corrosive to yellow metals like our syncros)
3. Lighter viscosity gear oil or syncromesh.
4. ATF
5. 10w30 engine oil

If your going for increased fuel milage or something for winter a 5w30 viscosity gear oil or atf would be best. I think honda MTF is thinner than atf even, atf is thinner than 5w30 if i recall correctly. But the transmission will work fine with any of those. Its grinding gears, fast shifting, non oem clutches, towing, running out of oil, no clutch shifting that kills the transmissions. The type of oil only helps for towing maybe and a bit for fast shifting when racing around, for any of the rest it makes no difference. Changing your output shaft seals before they start leaking is the best way to make your transmission last longer. After not trying to break it that is.

Sent from my SM-G920W8 using Tapatalk

[harpon]

This may qualify under your "B.S" heading but chalk it up to science and call it EXPERIMENTAL

Mine has been leaking (96 Aspire 5 speed) for a couple of years now, and I just had the CV axles replaced, so I'm not sure how that will affect things.

When I became aware of the leaking (I park on grass and it's hard to monitor) I started filling it with thicker gear oil in hopes of discouraging it. I also put a little copper stop leak in (2 oz or so) and that seemed to slow it down too. Anyway,

I've been running VERY thick 85-145 gear oil for a year now and NO PROBLEMS with tranny shifting (I'm not a racing person- only trying to get more miles out of my daily driver of the past 15 years and only 130 K on the clock)

After the CV's the mechanic said the car only took a quart of gear oil and handed me back one of them- I didn't know if that sounded right- but didn't know how much the CV change might deplete the pool- it takes almost two and half I think in the specs.

So as soon as I could in the mid summer heat I got around to checking the level and it was rather down- I don't know if it leaked that much or never really got filled. ANYWAY,

at that point I'd hit on a new idea, and so when I filled it up, I added a healthy dose- several good tablespoon dollops - of RED GREASE to the mix and figured the gear oil would break it down- be EVEN THICKER and maybe not leak as much-

That's been a month ago, and so and I've yet to check it again- which I hope in the next week or two, to get another fix on how fast it might still be leaking.

My point is that I've now gone BEYOND the heaviest Wally World Gear oil 145 sae and not experienced ANY tranny difference.

When this first started I was suffering a falling shifter and thinking it was tranny- I put expensive syncromesh in which leaked out rather quickly but did solve temporarily my "shifting Problems" until the shifter fell through the floor and I did a window weld fix- two years ago and no troubles since- only the annoying leaking- maybe a little more than a quart a year.
So I've actually ran the gamut from expensive thn syncro-mesh- that may only help the leaking along! to heavier than heaviest

I'm hoping the CV change and the heavier mix will slow that down, and I think that even if the level falls shallow now- I'll still have some lubrication on the vital parts

anyway that's been my experience- If I can get a reading I'll report back

[zoe60]

I use ATF. Works fine. My transmission used to leak. I think it was overfilled. I removed some fluid til it was just shy of the full mark and it hasen't leaked since. Simple, but true. I think it was coming out of the vent, dribbled down, and made it look like the axle seals were leaking.

[hot4dl8ly]

I've had good luck in the past using ATF. Now using BG syncro-shift, seems to work fine. I would recommend if you use gear oil - use synthetic so it doesn't get as thick in the cold weather.

[Greywolf]

* The reason I popped this thread right now at this point in the turning of the ages - is because I am about to build a spare tranny with a kit (MTI5 / M5 Ford)

https://cobratransmission.com/m5-aspire-synchro-bearing-gasket-and-seal-kit-50124003-1?gclid=Cj0KCQjw9NbdBRCwARIsAPLsnFZnuzVm7ALn6XJ9PEotqzs9rHDpm_v-LvwQn1RNiFZnxIg0pGNCWwcaAjRFEALw_wcB

https://www.transmissionpartsdistributors.com/categories/manual-standard-parts-rebuild-kits/fti4-fti5-ford.html

Above are two links to the bearing/synchro/seal kits I am looking over. The second is likely the one I will use...

If I do this, I want it protected from the start, but it also looks to me like other than the synchro's the bearings are pretty standard, so why the hell we use ATF in a manual box is beyond me, gang! I think it's one of the dumber things the engineers have come up with frankly, it may be that the whole business is about FORD coming out with a new ATF (MERCON) formula that they very much want us all to buy from them...


:???:


UPDATE: I just spent 95 bucks at the second link, so you guys can buy all the rest of the kits out and I still have one on the way... ccasion5:

[Greywolf]

FOOTNOTE(s):

BK200WS seems to be a standard part # at the second link, the transaxles are listed as these:
FORD ASPIRE '94-'97 1.3L (M5)
FORD FESTIVA '88+ 1.3L (FTI5)

*FT "EYE" 5, I wondered about that too, in case you thought it was a number 1 (one) or 15 (fifteen)


Cobra seems to be two bucks cheaper if that matters to anyone. All I care about at this point is getting the parts and I heard about TPD weeks ago
The MSRP is a LOT higher and by dragging my heals I saved fifty cold hard coins...

(two months ago they were listed at $168.oo)

I hope that doesn't mean they are running out and getting rid of them- that would suck

[Rick the Quick]

Synthetic gear oil seems to make the most sense. I used to drive a large commercial truck with 10 speeds. It was a Penske lease truck. At the first major service 50K? they changed the transmission oil and replaced it with synthetic gear oil. It sure made shifting easier specially on a cold morning. $95 is a good price on the kit.

[Dragonhealer]

After some reaserch and experimentation, we have decided to run Redline D6 (ATF) in our E, F, and G series transaxles.

[Sid_RallyX_82]

What series is the stock transaxle?

Also, my trans is filled with Ford compatible automatic transmission fluid (I know there's a debate about the difference of "ATF", so I'll just specify) and 2nd gear grinds. I'm not exactly sure how slip-stop works in automatics, but has anyone tried using it to stop your gears from grinding on a hard shift? or would it be better to just try a heavier oil?

[N47H4NI3L]

What series is the stock transaxle?

Also, my trans is filled with Ford compatible automatic transmission fluid (I know there's a debate about the difference of "ATF", so I'll just specify) and 2nd gear grinds. I'm not exactly sure how slip-stop works in automatics, but has anyone tried using it to stop your gears from grinding on a hard shift? or would it be better to just try a heavier oil?

Get some Nulon G70 from Australia. Add the whole tube to fresh gear oil. If that doesn't help make it feel nice, nothing will.

Sent from my SM-N950F using Tapatalk

[hot4dl8ly]

I was looking at manual transmission lubes online and found some surprising results. The Ford synthetic manual trans fluid (XT-M5-QS) has great reviews, especially from the Miata forum guys. It's a little pricey though, looks like $25 - $30 a quart, But they say it smooths out shifting - dramatically.

[Greywolf]

A thing I keep thinking is that trans fluid is essentially HYDRAULIC fluid, and is a much thinner viscosity than even 5W whatever oil. I also remember both H-3 Helicopters and F-14 aircraft leaking red pools all over the hangar floors...

(If they didn't leak - they were probably empty, just like a Harley)


So far the one comment that concerns me some is a note about wear caused to "YELLOW" metals, like the synchros
Anyone got any amplification on that?

I read somewhere recently that the synchros (if the gear lube doesn't leak past the axle seals) don't generally wear much unles they get hammered on and/or "BANG-shifted" constantly (shifting with no clutch use)

[ryanprins13]

So far the one comment that concerns me some is a note about wear caused to "YELLOW" metals, like the synchros
Anyone got any amplification on that?

I read somewhere recently that the synchros (if the gear lube doesn't leak past the axle seals) don't generally wear much unles they get hammered on and/or "BANG-shifted" constantly (shifting with no clutch use)

Well i said it so i will try to elaborate. The only reason i brought it up is this thread was about the BEST oil. Anything works. But GL-5 gear oils have extreme pressure additives to meet the GL5 specs. EP additives corrode yellow metals to varying degrees depending on which additive they used. Some only have a 1b rating which is good, some are in the 4s which is real bad. I was comparing a redline product and an amsoil, i went with amsoil because it had a 1b or 1a rating, the redline had a 2b. Our transmissions do not need extreme pressure additives, a GL-4 rated gear oil is perfectly fine.
So here is the copper corrosion test strip:


a link i found describing what happens a little more. The oil (additive in the oil) itself corrodes the brass/copper. https://www.machinerylubrication.com...itives-effects

And here is a comparison of some gear oils. Basically all high quality synthetic stuff but some are very corrosive:

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://www.lastgreatroadtrip.com/wp-content/uploads/2010/11/gear-oil-comparison.pdf&ved=2ahUKEwiZ08HmhoLeAhXk5lQKHQ2EAegQFjAAegQIAhAB&usg=AOvVaw38Fnzue5KZSglKZNn0vR3v

Here is a screenshot from that:

Some companies post their specs for their oils like this, but mostly you have to go to a site like bitog where people post oil analysis info. Anyway, hope some of that helps


Sent from my SM-G920W8 using Tapatalk

[FB71]

Original fill (yes, I was working on these when they were new) was a low-viscosity oil with anti-foaming and surficant agents, undyed. Ford's service info called for replacement with Mercon ATF. That was the closest to original fill that was in Ford's inventory. When Mercon V became available in the early 90's, it was excluded from the approved fluids for manual transmissions and transaxles. Merc V synthetic has too low a coefficient of friction for synchronizers. Synchro blocking rings are essentially brakes grasping the speed gear, and matching its speed to the shaft on which it lives. Merc V didn't allow enough grab, resulting in grinding during shifting. The other approved fluid was 10W-30 S class engine oil. However, I've found this to suffer from aeration at extended elevated speeds. After the discontinuation of Mercon, and prior to the availability of the Motorcraft XT-M5 oil, I used a 50/50 mix Merc V and 10W-30. Fluid exhibited little to no foaming, and lower shift effort than straight Mercon. I found the XT-M5 fluid to be far superior in shift feel, smoothness, and effort to prior fluids. A cursory temperature measurement with an IR gun shows slightly lower temps after sustained highway speeds as well. I have no experience with aftermarket fluids in these units.