My experience with trans oils in my 323 gtx

[festyfreak39]

Hey all, just thought id share my experience with the oils i have used in my gtx, if i found a thread like this about 3 months ago, i would have saved TONNNS of cash experimenting with different oils to see what yielded the best results, so im sharing my experience for future g series/ gtx owners.

some back ground: the car itself only has 170,000 kms. for a 1987 thats not alot IMO, but from fast 1st to 2nd gear shifts and fast 3rd to 2nd gear shifts there is an infamous grind. The transmission is getting a complete overhaul this summer but for now this is my experience with the oils i used.

1)ATF (was in the car when bought).... Worst oil, grinded no matter what from 3rd to 2nd gear, and any shift from 1st to 2nd above 4000 rpm it grinded hard.

2)10w30 as per club protege (just as bad as ATF). Grinded from 3rd to 2nd unless going under 30kmph.. 1st to 2nd grind was bad to.

3)75-90 full synthetic amsoil baller yo.... Used this in my miata race car... 2nd best oil i put into my trans. 3rd to 2nd was ok under 50kmph.. 1st to 2nd grinded anything above 5000 rpm.

4) Syncromesh gear oil from GM, Id say same deal as the 10w30.. grinded from 3rd to 2nd unless going under 40kmph ish, 1st to 2nd grind at 5000 ish rpm


And lastly the best oil:

5) 80-90 ac delco (cheapest gear oil i could find).... AMAZING!!! completely transformed my transmission. no grinds from 1st to 2nd, 80 kmph downshift from 3rd to 2nd without a grind provided i did it slowly and with the clutch all the way down. Even cold the trans was ok, and im talking -30C

Moral of the story, 80-90 cheap gear oil yielded the best results, and it was the cheapest in my case!

[Nerd Racing]

Good Tip! I need to do the oils in my protege case and in the rear diff too!

[festyfreak39]

Good Tip! I need to do the oils in my protege case and in the rear diff too!

Glad this will help some people, ive spent way to much $$ in oil over the last 3 months. the biggest surprise was the syncromesh, garbage for our transmissions.

[Ford Fester]

Yeah my gtx has a minimal grind going into second. Ill try it.

[Nerd Racing]

Mine does it 2-3-4 and is a pain when cold. I figured it was due to my bushings in the shifter being toast (which I cannot seem to find, may have to make some...). I'll see what the oil difference does. What is your impression on the rear diff, I was going to stick with the factory 75w90 recommendation for that.

[festyfreak39]

Mine does it 2-3-4 and is a pain when cold. I figured it was due to my bushings in the shifter being toast (which I cannot seem to find, may have to make some...). I'll see what the oil difference does. What is your impression on the rear diff, I was going to stick with the factory 75w90 recommendation for that.

yah im running 75-90 no problems, no noise or anything.

[Advancedynamix]

Thanks for posting this! I was going to try syncromesh, but I'm glad I didn't waste my money and time. I currently use b&m trickshift which works good, but the tranny shifts hard sometimes from second to third when it's hot. It doesn't grind, but it has caused a couple missed shifts. It may be from my clutch swelling from heatsoak and dragging a little.

[Nerd Racing]

^^ I wouldn't run that high of a weight in a fwd trans though... well maybe in Arizona where its hot most of the year.

[Bert]

Now, pouring 80W90-weight gear oil in an ATF-purposed tranny, to me, is much the same as tossing in a can of molasses, STP or a couple of banana peels. You may want to consider doing the rebuild sooner rather than later.

There were Consumer Reports, from Australia (as I recall) quite a few years ago where various transmission oils were scientifically tested. "Royal Purple" won hands down, Even the visuals (wear on the test metals) were brutally obvious.
Couldn't get that stuff around here at the time but when I finally did find it last summer it has gone into all of my cars. Even my manual 5-speed Ford F150 tranny (called an M5ODR2, made by Mazda - 1987 to present) specifies ATF.

[sasquatch]

i have 80/90 in mine, works good

[gauge_half_inch]

I've always used 80w90, atf always felt horrible when shifting. The hotter the trans got the worse it felt. The only downside of the thick gear lives is when its dead winter, it can be a little stiff shifting for a few miles then its all good. I also never thought atf did an adequate job of clinging to the parts at the top. Everyone has seen the Lucas oil demo at the parts store comparing regular oil to their addative, imagine a super thin fluid such as atf, you get where I'm goin here?

[Rocketman]

+1 rep left.

Ford actually revised their recommendation tables and says to use 80w90 in any climate that sees temps above 0°F. Google "G5MR Fluid type" or "G25MR fluid type"

I've used 80w90 for years now and it works great for me, a lil stiff in the winter but I'm okay with that. Friend had synchro issues with ATF, switched to 8090, problems gone! ATF is too thin and doesn't have the proper modifiers to keep the synchros happy long term, it's meant for clutchpacks in an Auto slushbox.

[Bert]

Of course you don't realize that the fragile soft alloy synchromesh teeth and wheels are quite different from the actual hard steel running gears? 120W240 'earth-mover sludge', Banana peels, sawdust or mud in the oil might have you believe that tranny use and shifting is improved but not using the proper-engineered lubricant is likely gonna cost ya in the long run.

But it's your investment and time, your car and your tranny, and I'm always open to being proven wrong.

[Rocketman]

Of course you don't realize that the fragile soft alloy synchromesh teeth and wheels are quite different from the actual hard steel running gears? 120W240 'earth-mover sludge', Banana peels, sawdust or mud in the oil might have you believe that tranny use and shifting is improved but not using the proper-engineered lubricant is likely gonna cost ya in the long run.

But it's your investment and time, your car and your tranny, and I'm always open to being proven wrong.

Here's some pretty in-depth information that corroborates with Mazda/Ford's revised tables: http://www.mazdaspd.com/resources/Tr...on_Rebuild.pdf

[nitrofarm]

+1 rep left.

Ford actually revised their recommendation tables and says to use 80w90 in any climate that sees temps above 0°F. Google "G5MR Fluid type" or "G25MR fluid type"

I've used 80w90 for years now and it works great for me, a lil stiff in the winter but I'm okay with that. Friend had synchro issues with ATF, switched to 8090, problems gone! ATF is too thin and doesn't have the proper modifiers to keep the synchros happy long term, it's meant for clutchpacks in an Auto slushbox.

I googled it.Not finding any Ford tables. Lots of jibberjabber between racers just like on this forum. But nothing written in stone from Ford.Can you post us a link? Thanks-