Choosing a transmissoin oil

[Pottsy]

Changing my Auto Transmission fluid for the first time.

When Castrol recommends two which one do you choose?

[mrbitchi]

I give my vote to genuine Mitsubishi oil.

[MickSA]

I have been led to believe there is no such thing as "genuine mitsubishi oil' It is manufactured by Castrol

[captain_paj]

I did a LOT of research into this and could find no definitive resource to confirm the oil is produced by Castrol. I found anecdotal evidence to indicate that the oil is produced in Australia by Castrol to MM specs and has specific additives to make it Mitsubishi Dia Queen SPIII

When I bought my NJ it had a rebuilt transmission in it with not a lot of Ks since the rebuild. The transmission was misbehaving, and I was having a lot of trouble keeping it in overdrive.

My transmission guy (a fella I do computer work for) told me the transmission rebuild was faulty and I should go back to the rebuilders. I asked him about the transmission fluid and he told me Dexron III was the right fluid for it.

Problem is when you look at the viscocity figures for DXIII rated oils it just isn't the same as Dia Queen SPIII.

All of these manufacturers state they meet certain specs but they meet a VERY broad range of specs - and you can line up 5 different fluids that supposedly meet Mitsubishi's standards, yet when you check their specs they all have different specs.

I argued with my transmission guy that I believed I would see an improvement going to the MM supplied Dia Queen SPIII (which wasn't the fluid for my transmission initially but MM say it is the replacement for SPII and is fine to use) and that my problems with OD were heat. He told me I was full of crap.

I didn't listen to him. I relocated my transmission cooler as the Bocar bullbar was stopping all airflow to the cooler. This fixed my OD problem instantly. Went to MM, bought 16L of their finest SPIII, was pleasantly surprised at the price, went away and flushed my tranny. I used 12L to completely flush to get to clear fluid.

INSTANTLY my problems with my transmission went away, and I dropped 250RPM @ 100km/h - and no more problems with heat. Fluid is still dead clean now after 10000km or so.

Of course the above is again anecdotal, and with an older vehicle, and as I'm always told "todays cars are built with tighter tolerances and require different oils"

I'll stick with the MM fluid. More than engines, automatic transmissions use solenoids and balls and galleries to manipulate the passage of fluid through the transmission. I want that system to be operating with a fluid that performs as the MM engineers expected.

IMHO an auto tranny is FAR more complex in operation than an engine, in terms of its oil needs. It does not just need the fluid for lubrication, but for torque converter conversion of engine inertia into mechanical input into the drive system, heat dissipation, and controlling shift points and positions of gears, as well as keeping my clutch plates in tip top condition.

My diatribe above is based on Dia Queen SPIII in my NJ and I have no idea what yours takes - but I personally would only ever run the proper stuff in mine.

And yes I'm a hypocrite - I have NO idea what is supposed to go in my engine, I run Castrol GTX 15-40 'cos it's cheap, and I change it like I change my undies - well I will once I fix my oil cooler hoses as I'm losing 1/2 a litre a week or more right now. Actually after the degrease and power wash I did on the weekend, the oil cooler hoses are leaking at least twice as fast now...But that's another story.

Oh and P.S. - Auto tranny in a 3.0 NJ sucks on road, is pretty nice off road. Go figure.

[Pottsy]

Thanks cap. Sounds like a good argument to me. I'll call for a price today.

[psproule]

Further Potsy, there is a long documented history on these forums of Gen 3 transmissions playing up only to be solved when switching to the Mitsu ATF. The other thing common with them is shudder from the torque convertor lock-up clutch.

Pat

[Pottsy]

Further Potsy, there is a long documented history on these forums of Gen 3 transmissions playing up only to be solved when switching to the Mitsu ATF. The other thing common with them is shudder from the torque convertor lock-up clutch.

Pat

Hi Pat, Brilliant! Thanks for that. I have what I would call a shudder in the gears and am hoping that may be addressed. I just rang MM and at $46 for 5 litres why go elsewhere? A comparative price IMO.

[wrexy]

$42.60 incl. gst. here in Perth last week for Dia SP3.

[captain_paj]

Hi Pat, Brilliant! Thanks for that. I have what I would call a shudder in the gears and am hoping that may be addressed. I just rang MM and at $46 for 5 litres why go elsewhere? A comparative price IMO.

If you are like me, your shudder will go away straight away - accepted I have a much older design transmission...

Are you intending to completely flush the system or just replace what comes out when you drop the pan? I would strongly recommend completely flushing, which is a bitch of a job (take off hoses at cooler, put in bucket, run car in Park, note which hose is outlet, when fluid starts spurting stop engine, pump new fluid into the inlet hose - well that's how I did it, I found there's no way I could pump fluid in fast enough to keep up with it coming out)

Allow 12-16 litres for a flush. Yes it's a lot. It's worth it IMHO. Suggest you don't buy 12L and run out while you are doing it (although I managed to JUST do it on 12L, plus a bit out of the 4th bottle to top up through filler tube)

[schnitzel]

ok a couple of things here, the castrol tqms-t is an obsolete product in the castrol range, it has been rebranded and name transmax multivehicle for the retail market to fit in with Castrol/BP's global naming protocols, so those 2 products are actually only 1 now available unless you find old stock on a shelf. In the workshop range I.E 20 L drums or larger it is called Transmax E.

As for Castrol being the OEM supplier for mitsubishi, up until recently I was the Castrol distributor for central Victoria, which included delivering the genuine mitsubishi oil to the mitsubishi dealers that used it. the products even had both a Castrol product number and a Mitsubishi product number, it was however only allowed to be sold to authorised mitsubishi dealers an mitsubishi's own account.

[mrbitchi]

The correct flushing procedure is attached. You should only need to do the first bit, the transmission fluid replacement.

[Pauly Faulkner]

The correct flushing procedure is attached. You should only need to do the first bit, the transmission fluid replacement.

Top link Mrbitchi

[Pottsy]

Are you intending to completely flush the system or just replace what comes out when you drop the pan?

I think this time I will just replace what comes out. I don't have a high level of confidence in myself so I'll keep it simple for now.

[Pauly Faulkner]

It's a relitively easy procedure Pottsy, disconnect hose and place in bucket, start in neatrul and let it run until the flow decreases then stop the car, top up then repeat again until you get nice clean fluid coming out. Then do the drain at the plug and fill as per normal
The drain and fill at the plug removes stuff all old fluid, kinda like removing 1/3 of engine oil, topping it up and calling it an oil change

[Pottsy]

It's a relitively easy procedure Pottsy, disconnect hose and place in bucket, start in neatrul and let it run until the flow decreases then stop the car, top up then repeat again until you get nice clean fluid coming out. Then do the drain at the plug and fill as per normal
The drain and fill at the plug removes stuff all old fluid, kinda like removing 1/3 of engine oil, topping it up and calling it an oil change

Thanks Pauly, You’ve talked me into it. You make it sound quit easy. Will I now need to purchase 12 litres to do the job?

I note that MM sells 5L of SP3 for $46 each and Supercheap sells 4L of Castrol Transmax Multivehicle for $47 each so it would be logical to go with MM.