What is the best thing to use in a Manual Festiva Transaxle?

[Icedawg]

So, we need 2 categories for this question
#1. Normal-Lead Foot driving use
and
#2. WOT use.

I agree with that.
WOT use:
ATF in a Mazda 1985 RX7 RWD transmission for racing was a total fail. A friend used it based on comments from circle track guys, and it destroyed the synchros and seals in one day in his road race car. I rebuild them, and he gave it to me to take apart. The synchros were worn to nubs, and oil dribble-leaked out of all the seals. There was lots of grey goo in the oil and on the magnetic capture plug too, indicating a lot of gear wear. In one day!
Redline MT-90 works well in the same transmission (a 75W90 gear oil with various additives). There could be something better, and I have seen comments on the Spec Miata forums (basically the same transmission with minor updates) that a variety of other more expensive choices might be better. Motul transmission oils are suggested, and Torco racing tranny oils, but it all comes out as opinions as to which is better. Anyhow, in racing ATF was a disaster, and Redline is a great safe fallback even if there could be something better.

I use Redline MT-90 in the FWD G25mr tranny in my winter raced ice racer, as it simply does not get as hot as in summer racing, and it starts from way colder. It works very well, shifts well, wears well. Oil changes once a season do show some brass from the synchros, but not a lot.

I have rebuilt G25mr, the e-series, 1980's RX7, and 99 Miata. Inside they all look like a Mazda sourced design, but I can't judge tolerances and maybe there are some differences there. But aside from the change in geometry for FWD vs RWD they look pretty similar, with an identical synchro design (except second in the 99 Miata), same cone angles, similar preloads on the bearings. So I think what works in one should work in the other for the transmission. Of course, there is also a diff in the FWD, but it does not use the same design ring and pinion, hypoid gear of the rear diff in the RX7, so it should be fine with the same gear oil as the tranny.

Redline shows the 75W90 gear oil is about the same weight as 10W40 engine oil. So the 20W50 engine oil Advance is using is higher viscosity still.

The additive difference between engine oil and transmission oil is important, and makes automobile engine oil seem a poor choice, but as Advance points out, motorcycle engines are special, so their additives may be better adapted to a transmission's needs. His low wear certainly suggests it works in WOT conditions.

Street use:
Manufacturer says ATF, they can't be totally wrong. But the WOT experience I have with ATF above says I would never choose to use it in any circumstance for a manual transmission.
Manufacturer says gear oil is good in Australia for the same tranny. Redline MTL works well racing, it is a good gear oil, it should work well on the street too. Other companies make similar mixes, and it is pretty hard to get really good data to choose between them, while on forums flame wars are fought over redline vs amsoil vs Royal Purple, with little hard evidence. For the street I suspect any of these will give the same performance and life. Certainly the Penzoil Synchromesh mentioned in this thread has good looking specs.

[fezzy]

na , no flame intended, just attitude, < grin >

yeah well that is true, some gearboxes hold, and some don't. People I spoke with do gearboxes to, mainly 4WD and racing. I've worked at the 4WD place till the dude retired recently and yes have seen lots and lots of metals come out in the oil changes. But that is 4WD fraternity.

Had us debating the same issue we have here, why the F does ATF go into those Festiva manual gearboxes ? It was the racing dudes that passed on the links to Redline and that other mob, I don't think they want to be too pestered over a 1.5 or a 1.3 Festiva gearbox oil when they have problems of their own with a blown 4 wheel gadget that does 1/4 mile in 8 seconds !

The jury is still out then ?


I think, there is a specific lighter manual gearbox oil out there that is not ATF, but has the same viscosity so it splash/lubricates where thicker gear oil won't get to, and it's not motor oil.
That is the point me thinks.

[Icedawg]

I use Redline MT-90 in the FWD G25mr tranny in my winter raced ice racer, as it simply does not get as hot as in summer racing, and it starts from way colder. It works very well, shifts well, wears well. Oil changes once a race season do show some brass from the synchros, but not a lot.

oops I meant I use Redline MTL in the winter season, since it is lighter. It would be a fine oil for regular driving based on the experience racing it, and it is certainly light enough to splash well.

[ryanprins13]

Heres a link to the viscosities of a whole bunch of different mtf if anyones interested. http://www.bobistheoilguy.com/forums...Number=3024238
I was wrong with what i said earlier about 20w50 getting as thin as atf racing vs daily driving. 20w50 is much thicker than i thought and has a lower viscosity index. I didnt realize it was much thicker than 80w90. It also would be considered a solid a couple mornings a year here. Transmissions need fluid, not solids
But, my trans temperatures are about 125f after an hour drive in the morning mostly on the freeway. 140f when i got home today and it was hotter out. Super hot day towing a trailer up steep hills it was 150 or 155, this is all with atf.
So at 125f the atf is 24.4cst and the 20w50 is 110cst. The atf at cool morning operating temps is the same viscosity as the 20w50 at the boiling point of water. The 20w50 is thicker than room temperature 15w40.
At warm day operating temperature of 140f the atf is 19cst and and the 20w50 is 78cst.
At 155f the hottest i have ever gotten my transmission the atf is still as thick as 15w40 at engine operating temperature (212). The 20w50 is like 60cst still.
For 20w50 to equal the viscosity of cooler atf (122f) you would have to get it to 200f. That about as hot as you could possibly get a transmission, i dont think they ever get that hot. Coolant runs about there when racing and your engine oil gets to maybe 230 when racing. I cant see a transmission getting past 180.
But if it works it works, thats just some info. The link above is a good source for different mtf options.
Generally you want something close to the viscosity of what it was designed to take unless your running it way hotter or colder than what it was intended to. Like running 5w20 in my festiva engine works well in the winter yet i use 5w30 in the summer in my civic instead of the 5w20 it calls for because when i put a roof rack and bike carrier on and go through mountains the 5w20 gets up to like 250f and falls off the dipstick and you almost burn yourself on the dipstick and all the plastic is soft.
A transmission in an nsx could take a different fluid than my civic because their built differently even though their both honda's. Just like a big diesel truck needs different oil than a small gas hybrid.
That being said i dont know what would be considered exactly optimaly right for this transmission. Apparently superthick viscosity works if the additive package is right. If your just daily driving and doing the occasional 1/4mile with a stock motor prettymuch anything will be fine. I went over 200,000km on 10w30 and atf. Mixing both even. Many people never change their trans fluid.


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[fezzy]

Some added research, know a dude at Harley Davidson, they got their own oil for wet clutch applications and gears, FORMULA +
There is not much specific technical info that I can find, but the it's not ATF, it's gear oil/wet clutch and primary chain lube, according to the basic info I could gather.

Bought 1 Litre, (out of respect for his time), looks OK, runs back into the bottle well, not thin like an ATF and not thick like a 80 or 90, and I believe it's not engine oil either.
But there are no specs to read into it, except some on various forums have mentioned it's good, but use another product after warranty expires on their respective HD.

Jury ?

[jason_]

Mineral spirits. Keeps any shavings washed out and at the bottom of case.

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[fezzy]

Mineral spirits. Keeps any shavings washed out and at the bottom of case.

Then adding a magnetized drain plug or super-glue a magnet to catch those shavings.

[jason_]

But seriously, atf to keep it on the thin side, if it's warm I'll mix a quart of motor oil to thicken it up.

Never had an issue as far as I can tell related to oil type.

Seems to be my headaches are too much torque, snapping the clutch (sliding foot to the side, not picking it up), red line 4th gear 1 wheel spins, then snagging dry pavement, that raises hell on the spider gears too.


No, I don't worry about lube. For what I do any lube is OK.

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[denguy]

I always had trouble pulling out the speedo thing to check the oil level, even breaking off part of the hold-down tab. So I drilled and tapped a 1/4-20 hole through the top of the case next to it and and put in a bolt.

[harpon]

So what is the SAE of the syncro mesh? Anyone know? Going through this with my Aspire. The shifting started getting hard especially second. When I checked the level, there was NO level- a small drip had drained it for awhile I guess, Didn't see it on the driveway.

I put in the 80-90 gear oil- KIA seemed to list the same kind of fluid, and it helped the problem quite a bit, buit obviously some damage was done. I kept adding more fluid- lighter oli to it- that helped more until I overfilled it- then the problem got worse when hot- and its been warm in Florida.

Today I drained some out with a baster- I was surprised how dirty t looked after a full change and two weeks- musta baked some gunk inside when it got lower over a longtime-

so now Im going to change out again- I still have enough gear oil- Do you think it's a hold over from the rear differential days? AUTO fluid- sounds a little weird, but some swore by it.

- but I was just thinking I might put some of that in to at least get more system flush and see how it worked- and I could change back later if I need.

It ran today as well as it has since before the problem- so I'm pleased about that- only has 120 K otherwise.

[harpon]

So I just put 2.6 quarts of Pennzoil Syncromesh in- #3 quarts bought at 8.99 Autozone in stock. Treated rudely- babbled at and kept waiting. THEY are training ME again- and I'm 62- old and tired and tired of that "we're helping"' attitude. Well, I'm not having a picnic trying to keep my 96 on the road, while you intentionally waste my time and babble at me! ty1

(Side note- 30 years ago today- my sex change operation. ttiwwp )

Went around three blocks and not ready to get out in Friday Rush Hour. Seems smoother- going into second still stiff but I may be sensing an improvement- too early to tell.

I'll have to retake a level reading in a day or two, and get back here how it's going then.

[fezzy]

Just a quick update, on the other thread I wrote that the car had to go for inspection etc etc.

Point is it was driven for the first time there and back, about a 20 mile round trip in traffic.
It has the Harley Davidson 100 + gear oil in transmission.
All seemed well, from normal driving to some back street hill climbs, and many gear changes. Nice and quiet.

Because my car was not entirely passed over trivial defects,( brake light globe and dust boot cover) I drove back home in a, "get-outta-my-way-pissed off", mode.

The trip back home includes 3 back street round-about, and 2 slight hill climbs.
The gear up , ( 3rd to 2nd) changes were stiff. Could not change gears as quick as I remember before oil change.
I could tell, as recommended for Australian conditions, the ATF oil seems to be easier on the gear changes.

[fezzy]

Correction:

It has the Harley Davidson 100 + gear oil in transmission.

is actually Harley Davidson FORMULA + gear oil.

Seem OK,Good,
but noticed stiffer gear changes from 3rd to 2nd when driving slightly harder than normal, in traffic or up a hill.

[harpon]

:clock: Penzoil Syncromesh Fluid- FAIL.

I didn't want this- I was hoping for the best, but here's my story, it's sad but true.

Went the six mile roundtrip to the grocery and coffee.

The transaxle is shifting harder than earlier today- The evaluation is not over completely- I have to double check the level but I don't think there is going to be any "drive smoother" effect here-

the transaxle- already suffering some syncro damage from having been run low due to a drip/leak I wasn't aware of- simply feels now LESS LUBRICATED than with the 80-90 SAE Peak Gear Oil I'd diluted very slightly with some 30weight.

In fact I have the feeling that regular ATF fluid would probably work better for me here than the syncromesh.

I'll probably try to change it out again after another drive just to reconfirm what I don't think will change now- the shifter simply feels as if it doesn't slide into the gears as well now with the thin fluid. I could have saved a few dollars with 3 quarts of cheaper ATF- which I would have tried anyway- and I'm sure it'll be a great rinse and cleaning either way-
second- very bad again and more fussing into first - didn't get much time on the freeway to try fifth.

I have enough heavy gear oil to put back in- I'd bought a gallon last month, and another quart today, and I feel that at the correct level, that'll give me the best shifting I'll get without a repair.

It went from best it had done since the first change today back to about the worst performance- not happy.

A little paranoid and pissed over it frankly- it again leaves a vision in me on something suggesting that the powers that be who develop and market these things- simply are not that interested in much but trying to stimulate new trends, whether good or bad, to sell us more stuff alla time and keep us jumping for every buck.

Hey sounds like Waltzing Matilda!

https://youtu.be/y4NUZJMCJ20

[ryanprins13]

:clock: Penzoil Syncromesh Fluid- FAIL.

I didn't want this- I was hoping for the best, but here's my story, it's sad but true.

Went the six mile roundtrip to the grocery and coffee.

The transaxle is shifting harder than earlier today- The evaluation is not over completely- I have to double check the level but I don't think there is going to be any "drive smoother" effect here-

the transaxle- already suffering some syncro damage from having been run low due to a drip/leak I wasn't aware of- simply feels now LESS LUBRICATED than with the 80-90 SAE Peak Gear Oil I'd diluted very slightly with some 30weight.

In fact I have the feeling that regular ATF fluid would probably work better for me here than the syncromesh.

I'll probably try to change it out again after another drive just to reconfirm what I don't think will change now- the shifter simply feels as if it doesn't slide into the gears as well now with the thin fluid. I could have saved a few dollars with 3 quarts of cheaper ATF- which I would have tried anyway- and I'm sure it'll be a great rinse and cleaning either way-
second- very bad again and more fussing into first - didn't get much time on the freeway to try fifth.

I have enough heavy gear oil to put back in- I'd bought a gallon last month, and another quart today, and I feel that at the correct level, that'll give me the best shifting I'll get without a repair.

It went from best it had done since the first change today back to about the worst performance- not happy.

A little paranoid and pissed over it frankly- it again leaves a vision in me on something suggesting that the powers that be who develop and market these things- simply are not that interested in much but trying to stimulate new trends, whether good or bad, to sell us more stuff alla time and keep us jumping for every buck.

Hey sounds like Waltzing Matilda!
https://youtu.be/y4NUZJMCJ20

Post number 34 in this thread i had a link that has the viscosities of all different MTF's. Look at the date when you open it, its not too old, but not last week.
Manufacturers build things to die, but Dont get mad at them because your ran your transmission out of oil, lol