ATF to 10w30 swap - First Impressions

OB · Post by OB » Fri Dec 18, 2009 5:58 pm

Just finished switching over from ATF to motor oil in my MTX. I used Mobil 1 Fully Synthetic 10w30 High Mileage. All I did was a basic drain, static flush, and refill. I plan on changing it again in a few thousand miles to be sure the ATF is out, and possibly adding a small amount of Lucas oil stabilizer as well.

After letting the engine and trans warm up for several minutes while I picked up my tools, I took her for a spin around the block. Shift effort and feel seem unchanged for the most part. The main thing I did notice was that the noises coming from the tranny were nearly gone. Normally, when cruising off throttle in 1st or 2nd, a whirring, grinding type noise was apparent. I could even hear it with the windows up. This noise is now almost nonexistent, and I noticed it immediately on the test drive. Also before, a similar noise was made when the RPM is too low for the gear. I did not test this in the higher gears, but initial tests in lower gears show that this issue has also been greatly improved.

I have to say, I'm impressed so far. That noise, while considered normal for these trannys, has always bothered me, and I'm so glad to have gotten rid of it. Hopefully this behavior stays the same throughout the life of the new oil. I'll keep this thread updated as I get new data.

heydockyle · Post by **heydockyle** » Fri Dec 18, 2009 6:06 pm

I thought we couldn't run motor oil because it would damage our synchros.

OB · Post by OB » Fri Dec 18, 2009 6:10 pm

viewtopic.php?t=45781&postdays=0&postorder=asc&start=0

The racing guys don't seem to have any issues. Motor oil is superior to ATF in almost every way, except as a solvent/cleaner.

heydockyle · Post by **heydockyle** » Fri Dec 18, 2009 6:13 pm

Hmmmmmmm. Well If I ever get my trans to stop leaking I might be changing over.

OB · Post by OB » Fri Dec 18, 2009 6:15 pm

I'm looking forward to driving it cold, on the freeway, and ripping some corners with the new oil. Interested to see how it performs in all the other conditions this car sees.

heydockyle · Post by **heydockyle** » Fri Dec 18, 2009 6:17 pm

Well I know since my car is sitting out the past couple of days, it sounds like the TOB is grinding on the side of the trans case at 100+ MPH. So if this would quite it down, I'm game.

darthroush · Post by **darthroush** » Sat Dec 19, 2009 5:49 pm

OB wrote:I'm looking forward to driving it cold, on the freeway, and ripping some corners with the new oil. Interested to see how it performs in all the other conditions this car sees.

Let me know when you want to run it through some real corners, none of them city ones.

Post by **racer12306** » Sat Dec 19, 2009 5:55 pm

OB wrote:viewtopic.php?t=45781&postdays=0&postorder=asc&start=0

The racing guys don't seem to have any issues. Motor oil is superior to ATF in almost every way, except as a solvent/cleaner.

And as being an ATF

contagious18 · Post by **contagious18** » Sun Dec 20, 2009 6:21 pm

i need to really change my tranny fluid seeing that its making noises during cold starts. i might consider this

Mopar00Neon · Post by **Mopar00Neon** » Mon Dec 21, 2009 5:34 am

Since its late, and I dont feel like reading.....

Derek, tell me.. why M1 and not the original Mopar fluid (as in, the terribly expensive 'lifetime' shit thats been in my tranny for 70k miles, that the old school way of thinking always called for in anything neon, not the ATF+4 of the 03+ generation)

you can post, or txt me.... as ill probably be up fussing with the car tomorrow.

Adionik · Post by **Adionik** » Mon Dec 21, 2009 1:57 pm

Let me know how it does cold. My T850 absolutely HATES cold ATF4.

OB · Post by OB » Mon Dec 21, 2009 7:44 pm

Brian - M1 is cheaper, easier to get, and probably better than the old Mopar fluid. A win win win. From the research I've done, it's used by quite a few guys in the racing world, both road and rally.

My only concern with the swap was the synchros, and so far I've had no issues to speak of. There is nothing in a proper MTX that requires the properties of ATF. The fluid is not used under pressure, nor does it have to deal with extreme temperatures. There is hardly any wear in a MTX, no clutch material in the fluid like in an auto. Unfortunately, my preexisting shifting issue hasn't improved at all; still very notchy. Looks like the damage is already done I suppose.

fixitmattman · Post by **fixitmattman** » Mon Dec 21, 2009 8:00 pm

You guys are nuts. Mobil 1 is like $8/L, the mopar stuff is $13/L. You guys pay the premium to put mobil 1 in the engine over a conventional oil but cheap out and put it in the trans because it's cheaper than the mopar oil. Saving $20 on an oil change that happens maybe 2-3 times in the cars life at best. Where's the logic in that. IMO just put the NV-T350 oil or GM or penzoil synchromesh in it, know you have the correct additive package, and call it a day.

Don't get me wrong, I know a 5w30 oil will work just fine in a trans, but so does ATF for that matter.

OB · Post by OB » Mon Dec 21, 2009 8:12 pm

^ The fact that I don't have to drive 10-15 miles to a dealership, wasting time and gas, makes the M1 cheaper in its own way. The fact that it is also literally cheaper cost-wise doesn't hurt either. I payed $22 at walmart for my 5qt jug of M1 10w30 HM Full syn, which is enough for almost two trans oil changes. Since no one has proven that the NVG oil is superior (I doubt it is), I have no reason to spend the extra money on it.

And for the record, my car has 41K on it and is on it's fourth batch of trans fluid. 3-4 times per lifetime FTL.

fixitmattman · Post by **fixitmattman** » Tue Dec 22, 2009 11:08 pm

No one's done a one on one comparison of NVG fluid vs engine oil, but one would think that the MTX oil which the transmission was designed around would be superior to an engine oil, based purely on the additive package.

There was a fellow that did an oil anlysis on the NVG stuff:

http://www.bobistheoilguy.com/forums/ub ... ber=706573

Compare that to mobil 1 numbers. Proably find a few things quite different.

Post by **occasional demons** » Wed Dec 23, 2009 9:55 am

But OB's is designed for ATF, not NVG fluid that is used in the pre '03 MTX's

While there is debate about that issue also, I'm just going by factory fill.

OB · Post by OB » Thu Dec 24, 2009 5:26 pm

Have we found out whether or not there were changes from the old T350's to the current ones? I thought I heard somewhere that the 1gn ones were different, but I can't remember for sure. I assume the differences are in the synchro or shift fork assemblies if anything. I want to know if there is a technical reason for the fluid switch, or if it was indeed a cost related change. ATF is the last thing that a proper MTX should use, based on the research I've done. It's beneficial properties don't suit a MTX at all.

BTW - For those of you wondering, I've now driven with the new oil for a week now. I've gone to and from work, and a 120mi round trip to visit my mom. Outside temps have been as low as 30 degrees and around 60 at the highest. Shifting is notchy as always, and it does seem to get better as the trans warms up, like it did before.

Bottom line - aside from the noise factors mentioned above, I can't feel any other benefits when shifting. I wonder if a 5w oil would be better for cold starts...

Post by **occasional demons** » Sat Dec 26, 2009 1:20 pm

OB wrote:Have we found out whether or not there were changes from the old T350's to the current ones? I thought I heard somewhere that the 1gn ones were different, but I can't remember for sure. I assume the differences are in the synchro or shift fork assemblies if anything.

I read in different posts the difference was in the synchro's the NVG fluid type were brass, and the ATF type were fiber.

But the pn#'s Are the same for '01 and '04 So that blows that one out of the ball park. Being no superseded numbers would tell me that there was no change. Unless someone has pics, I'm betting they are the same part.

NickKo · Post by **NickKo** » Sat Dec 26, 2009 2:01 pm

heydockyle wrote:I thought we couldn't run motor oil because it would damage our synchros.

The Mobil 'High-Mileage' oil has sulfur and zinc addititives, which protect the factory synchros, just like the 'good' old MoPar MS-9417 fluid.

More information here:
http://forums.neons.org/viewtopic.php?f=48&t=352563

Mind you, *ONLY* the "High Mileage" Mobil One has the additives.

- Nick

OB · Post by OB » Mon Dec 28, 2009 10:27 pm

UPDATE: Noticed some new noises coming from the trans case when the engine cold. Sort of a sporadic grinding/pinging sound. It's not super loud but I could hear if from the drivers seat. Popped the hood and narrowed it down. I wonder if the oil is too thin in cold weather for the gears to be fully lubricated. It goes away once things warm up, which is why I think the viscosity has something to do with it. Hmmm.

woodchuckssuck · Post by **woodchuckssuck** » Tue Dec 29, 2009 1:09 am

I personally went with Pennzoil Synchromesh for my 2002 SE mtx. Been in for about 3k now, seems fine. What I drained out didnt look overly dirty or contaminated either. I did notice a bit slicker going into gear now, might have been in part of switching all 4 shifter bushings to Booger Bushings...which also made a huge difference.

I might switch to Amsoil synchromesh this spring. Would be $30 but a guy at work is an Amsoil dealer...Figure I might as well keep the Neon a while, as much as I want a 4x4 suv again...

Haganracing · Post by **Haganracing** » Tue Dec 29, 2009 2:30 am

Motor oil in the transmission.. interesting, never really thought about it before..

Hope the oil is just too thin and is the reason your hearing those new noises.

Post by **occasional demons** » Tue Dec 29, 2009 9:01 am

Too thin would not be an issue. Too thick is what prevents the oil from flowing to lubricate. That is the biggest reason not to use heavy gear oil in the T350. It is prolly flowing better once it warms. Put that 10w-30 in the fridge and see how fast it pours compared to warm. Better yet drill a small hole in a can, and see how fast it drains cold vs hot.

NickKo · Post by **NickKo** » Tue Dec 29, 2009 2:19 pm

Haganracing wrote:Motor oil in the transmission.. interesting, never really thought about it before..

Hope the oil is just too thin and is the reason your hearing those new noises.

Well, the Mobil One 'High Mileage' oil is a full synthetic, so it shouldn't get too thick with the cold weather....

Notice that I said, 'too' thick.
Full Synthetics will still flow slower, at really cold temperatures.

- Nick

Post by **racer12306** » Tue Dec 29, 2009 8:42 pm

Why would motor oil be too thin?

ATF has a similar viscosity to 5w20. So 10w30 wouldn't be too thin at any temperature.

The Mopar and AMSOIL MTF have a similar viscosity to 10w30 as well.

OB · Post by OB » Wed Dec 30, 2009 9:22 pm

Is that right? It was just a theory, I never really thought of how ATF's viscosity would compare with motor oil. I can't think of any other reason, other than coincidence, that the oil might cause issues with the tranny when cold.

I also might mention that shifting seems to have gotten a bit worse. My previous hard shifting issue seems to be more pronounced at times. Other times, it is the same. Definitely not better or smoother. I'm gonna feel pretty stupid if I played guinea pig and damaged the tranny even further:banghead: Oh well, this is how we find out what works and what doesn't.

Post by **occasional demons** » Wed Dec 30, 2009 10:11 pm

The viscosity when cold may affect the flow to lube the bearings slightly, but it shouldn't affect the synchro's adversely. The MTL in mine makes for stiffer shifter movement/effort in sub 30ºF temps, but it still goes through the gears just fine.

Donkeypuncher · Post by **Donkeypuncher** » Wed Dec 30, 2009 10:35 pm

Does the 2g T350 have the same paper backed synchros that the 1g T350 had? That was the main reason for using the mopar fluid, it had a friction modifier to keep the synchros from failing. That and not many other oils or gear lube had the correct additives in the mid 90's.

heydockyle · Post by **heydockyle** » Thu Dec 31, 2009 8:24 pm

Donkeypuncher wrote:Does the 2g T350 have the same paper backed synchros that the 1g T350 had? That was the main reason for using the mopar fluid, it had a friction modifier to keep the synchros from failing. That and not many other oils or gear lube had the correct additives in the mid 90's.

From what I'm reading thats why you use the high mileage, because it has what the synchros need.

And put the Mobil1 in my 1st gen, almost no noise compared to the gear oil that was in it for some reason.

INVUJerry · Post by **INVUJerry** » Fri Jan 01, 2010 7:12 pm

fixitmattman wrote:You guys are nuts. Mobil 1 is like $8/L, the mopar stuff is $13/L. You guys pay the premium to put mobil 1 in the engine over a conventional oil but cheap out and put it in the trans because it's cheaper than the mopar oil. Saving $20 on an oil change that happens maybe 2-3 times in the cars life at best. Where's the logic in that. IMO just put the NV-T350 oil or GM or penzoil synchromesh in it, know you have the correct additive package, and call it a day.

Don't get me wrong, I know a 5w30 oil will work just fine in a trans, but so does ATF for that matter.

Drakito over on neons.org has done a study, a lot of stuff will work sucessfully.

http://forums.neons.org/viewtopic.php?f=48&t=352563

I use pennzoil myself.