ATF to 10w30 swap - First Impressions

[Perfctsouljah]

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.

Like everyone has been saying, the only real worry about using the Mobile 1 10w-30 in the MTX are the synchronizers. Mobile 1 is a far superior lubricant compared to ATF+4. Although ATF is a good lubricant with a low heat tolerance somewhere around 200 F. However Mobile 1 should be able to properly lubricate the bearings and seals within the transmission along with superior lubrication of the moving parts. Synchronizers have four real parts to it: the Hub which splines to the input shaft, the Sleeve that splines to the hub, sliding keys, and the braking ring gears which eventually spline with the sliding sleeve once the keys have slowed the braking ring via dogteeth.

Here is a quick thought, Mopar uses a special oil additive for their LSD differentials (Shark Oil is the secret additive). I am not 100% positive on this so don't hold me to it, but in theory you should be able to try using this additive if your synchro's begin giving you trouble.

* It is recommended, and an appropriate course of action to fully drain and flush any MTX transmission before changing the fluid type. For example if Mercon has been added to a tranny that once had Type F in it, the Type F will actually convert the Mercon to Type F via chemical changes.

** An ATX can be filled with Mobile 1 if the tranny has been rebuilt or flushed with the gaskets, clutches, and bands (All fluid absorbent + friction materials) replaced. The Mobile 1 works better, but it takes around five seconds or so for the transmission to actually build hydraulic pressure compared to the ATF/Dexron/Mercon/Type F etc. tranny fluid which will have pressure almost immeadiatley on start up. The 10w-30 Lubricates better, can handle a higher ammount of heat, and will not break down nearly as fast as your standard tranny fluids.

I do not believe that you should have any troubles out of your tranny from changing this fluid as long as you keep a watchful eye on it.

If needed I can obtain a full transmission breakdown diagram and rebuild instructions. A synchro kit for the T-350 is very affordable if it comes down to it, and this transmission is a sinch to rebuild. It's one of the few transaxles with a removable bell housing.

There is a lot of good info in this thread.

[OB]

^You've rebuilt a T-350? I'm strongly considering freshening it up when I pull it for the clutch here in a bit. Shoot me a PM if you don't mind and we'll have a conversation

[Drakito]

The biggest issue most of the people are having is switching oils expecting it to fix all their problems when the 100K+ miles of damage are already done to the transmission. Its a better oil hands down, but if everything is trashed already the oil can't fix it. Its like changing oil expecting it to fix your rod knock, it won't happen, the damage is done and the only way to truly fix it is to repair it. Exactly the same with our transmissions.
By the way OB, I rebuild them and upgrade them all the time, see my sig for the link to my dealer page on the .org.
Dave

[OB]

UPDATE:

I've been meaning to post in here for awhile now.

So after running the 10w30 high mileage oil for a few thousand miles, I decided to drain it and switch back to ATF. My tranny sounded like it had marbles in it, especially when cold, the entire time I ran the oil. It got louder and more frequent as time went on. I'd say the noise started within a few weeks of putting it in, and got noticeably worse at a pretty fast rate. I left it in for awhile, figuring the noises were my tranny getting ready to die, which was the reason I switched in the first place, hoping to prolong the failure. I planned on bringing it in under warranty, so I began changing out any mods I thought might compromise my claim. I started with the shift bushings, then motor mount inserts, and finally I switched back to ATF. Sure enough, the sounds were all but gone the second I started it up with the new fluid in it. I can still hear it VERY faintly, but not at all at idle like I used to. I decided against taking it in, since I can no longer reproduce the trans-condemning sound. My notchy shifting feel would likely be considered "normal" per the dealer's standards, so I chose not to waste my time. When and if it blows up, I'll revert everything to stock again and have it towed in.

To describe the noise in more detail, it was a rattling sound, metal on metal, and it got much louder as revs increased. It happened at idle, worse when cold. I could also hear it with my window down driving in gear, especially near walls or tall curbs. The sound went away when I put the clutch in (about a second afterwards actually, isolating the transaxle as being the culprit. At first this sounded like an input shaft bearing type symptom, but now I'm not so sure. The sound seemed worse on decel than on accel when moving, but it honestly sounded terrible pretty much all the time. It did seem to improve a bit when everything was fully warmed up, but not much.

Keep in mind this tranny has 45K miles on it, stock clutch, and has had it's fluid changed 5 times now, three before the motor oil, so it has been extremely well maintained. I drive the car hard, but never for extended periods of time. I never do burnouts and rarely shift excessively fast. IMO an engine's rev limiter dictates a vehicle's max safe drivetrain speed. Therefore, every drivetrain component should be able to handle this limit. Aside from spending a good amount of time between 4k and redline, this car as a whole is babied almost everywhere it goes, so the issues I've had almost have to be due to defects in the equipment.

[r/tguy02]

I'd read this OB, sounds like your tranny might have the same issue
viewtopic.php?t=26856&highlight=accordi ... ler+normal

[OB]

I followed that thread since it was started dude, and it does indeed appear to be the same sound. Pretty sure his was much worse, based on the video and his description. This is why I haven't taken it in yet, because if mine isn't even making the sound now, they're going to laugh in my face. I'm pretty worried about the notchy shift feel though. It feels like I have boogers and a STS, but I'm all stock with a NRG shift knob. IIRC, when I bought this beast new it was super smooth and quiet.

[iskyfly]

heres for sticking with true, tried, and recommended by the manufacturer.

[racer12306]

Here's for going with what the manufacturer used to recommend but then decided to go with a cheaper alternative.

[heydockyle]

Derek that sounds like the TOB. My orange car did it pretty bad with 49k on it, then when I put the clutch in I changed the tob and it quited it down alot, but not totally. It only does it the first few miles I drive it, then it stops.

My car shifts pretty hard compared to every car I've ever been in. I still run atf in my orange car, but I've been running High mileage mobile 1 in my 1gn for like 5k miles now.

It also makes the same transmission noise as the 2gn. It's about the same loudness. With a short throw shifter, that has been cut down, it shifts about the same if not easier then the 1gn.


Until I have a reason to go back to ATF in the 1gn, I won't be.

[OB]

Normally a TOB will make noise when the pedal is pushed in, not when the clutch is engaged. Also, the TOB is in the bellhousing, which does not see fluid. I'm not ruling anything out though.

The T-350 is a piece of junk IMO, I've heard too many horror stories and experienced enough of my own.