Transmission fluid replacement

[jarl]

I need to replace the transmission fluid with a good synthetic, but the idea of throwing to the garbage (cross that...actually PAYING to get rid of) a couple gallons of it is not particularly amusing. And yes, I have read several threads about the 3 x drain & fill

 

So... Any compelling reasons not to do this ?

 

Some questions regarding it:

- If we disconnect the return hose from the cooler it wouldn't be necessary to blow air into the lines, right?

- Where in the circuit is the transmission filter? It would be nice to avoid running the old fluid through a new filter, but I don't think it's possible... is it?

[porcupine73]

I didn't watch that video but I have done the unhook the transmission cooler line method before. I drain the pan, refill with 5 quarts or so, start it up and let it pump a couple quarts out, shut it off, add a few quarts, repeat a few times. There is still some mixing that occurs, but much less than with repeated drains and fills from the pan.

 

If yours has the external spin on filter (4EAT phase II), the filter is at the discharge right before the fluid goes to the cooler. If you don't want old fluid going through the filter, then change the filter after you have completed the 'pump and dump'. If you have an H6 the filter is remote mounted. If you have phase I 4EAT, it either has no true filter (just a screen suction strainer in the pan), or may have a filter installed later resembling a fuel filter.

[davebugs]

Around her ehte chain auto parts stores have a waste oil tank and ATF is basically the same so that's where mine goes.

 

Also lots of independent shops and dealers heat with used oil and are typically happy to get it.

 

Heck - even check Craigs List often folks are looking for free waste oil.

[idosubaru]

same around here and Maryland and Georgia - autoparts stores, the big chains, and most shops will take gear oil or ATF any day of the weak for free. they recycle it or the shops will burn it to heat their garages in the winter which is what many probably do in Detroit, i imagine there are some brisk winter days there!

 

i've done the unhook lines before as well - fairly simple, just a little tricky that the lines are short to work with but not too bad on most EJ's with lines at the bottom of the rad.

[markjw]

I have done the 'unhook oil line' method as well. I've had good success in the past doing it that way on other vehicles, but I won't do it that way again. Recently, I was trying to resurrect a 4eat that had a questionable oil pump. I was attempting to replace the old fluid with new fluid using the pump and unhook oil line method, and although I got the fluid replaced and all seemed to have went well, the car never moved again after that. The pump was then completely toast.

 

So, I decided that the procedure is too much stress for the pump. I simply do it the way that is so often recommended on the board. Drain and refill three times.

[jarl]

Thank you people

 

The few times I have asked the chain stores if they would accept used oil the answer has been "we used to but not anymore", for whatever reason. So now I take them to the county's collection facility. You can take as much motor oil as you want, but they will charge you for the ATF if you go past a certain point. And they explicitly ask you not to mix oil with ATF. Oh well... I'll try again

 

Now... I was convinced about this until I read Mark's post. Anyone else has had a bad experience doing this? If the cooling loop is at the pump's discharge, and the fluid level is being topped while the engine is running, the pump should not run dry at any point, right? Am I missing something?

 

If I decide to go this way, which is the return line? I know I can experiment, but delving into the common knowledge is not that messy

[porcupine73]

I don't remember off hand which is the return line. I do not recommend pumping it until no fluid is coming out; i.e. letting the pump suction go dry. That is why I I will overfill by say a quart, then let it pump out two quarts, then add two quarts, and repeat a few times. Running the level until the pump suction is dry is not good for the pump though for a very brief period it might tolerate it.

[jarl]

That's what I have in mind, but Mark's post worried me somewhat.

 

And now reading a bit more I find this:

 

"Subarus do not like full flushes. It causes too many problems than it solves, mainly disturbing crud in the torque converter, which then gets dislodged into the main guts of your trans. those debris particles are better off staying in the TC"

 

[porcupine73]

Now it was true that the 4EAT phase I's, if they didn't have the added on external filter, could plug up the cooler in the radiator with shreddings from the TC and friction materials. Then the transmission overheats. That's why the 'add on' filter was introduced, and why the spin on filter was added on the 4EAT phase II. Subaru was light years ahead of other makers who did not go this route.

 

So I'm just saying that to say this - if your transmission is the 4EAT phase II (you haven't mentioned the model/year in the thread I don't think), then the transmission fluid leaving your phase II with the spin on filter is going through said filter before going anywhere else. So any TC shreddings that might get dislodged will be caught by this filter. And you're not hooking up a fluid flushing machine, right? You're simply replacing the fluid.

 

Generally the conclusion to transmission flushes/fluid replacement is....if the replacement 'causes' a transmission problem, the transmission had a problem to begin with. Some problems can be masked by gunk in the transmission and so on which then starts getting cleaned away by the fresh fluid.

[jarl]

Oops... I'm so used to have signature with the relevant information I forget to put it here

 

My car is a ''99 OBW, and it has the spin-on filter. From your post -which makes perfect sense, btw- I can see one way doing this may mess up the whole show: I think I read somewhere the filter doesn't have a bypass valve. If this is true, and there's too much crap in the oil the filter *could* get clogged, at least in theory...

 

I wonder if it would make sense to put a cheaper filter while doing the change, and replace it with the $30 thing afterwards...

 

Anyway... I think the case is made for trying this. Now let's search for the best fluid I can afford... which isn't that much to begin with

[porcupine73]

The genuine filter does have a bypass valve; it just has some metal screen over it so that at least large chunks can still not get through. Normal engine oil filters do not have this metal screening.

 

Do you get any delayed engaging into drive after a cold night? The early 4EAT phase II's are known for that.

 

For quality synthetics, Red Line and Amsoil are quite popular. Mobil1 synthetic ATF is a popular retail choice. Neo Synthetics makes some nice products, as does Schaeffer Oil, but both those are a little more obscure and harder to find. I would stay away from the Dexron VI and Toyota WS style ATF's; they are quite a bit thinner than the good 'ol Dexron III that ear soob uses.

[jarl]

It looks like the planets are aligning after all

 

My OBW do have the delayed engagement issue, and I'm hopeful the Trans-X additive mentioned in another thread can fix things somewhat after getting rid of the nasty stuff that used to be ATF in the transmission. I'm just looking at alternatives to get the best outcome possible wasting the smallest amount of money. Tall order -specially if looking for synthetics-, right?

[porcupine73]

I'm just looking at alternatives to get the best outcome possible wasting the smallest amount of money.

 

You should run for Congress!

 

The slow to engage to drive is a problem with a seal ring on one of the drums. Most likely the TransX makes this ring swell somehow to give a better seal. TransX used to offer their own brand ATF in addition to just the additive itself; not sure if they still do that.

 

Here's some links to some quality synthetic ATF's, though these particular ones are kind of obscure:

http://www.schaefferoil.com/transmission-fluid.html

http://www.neosyntheticoil.com/automatic-transmission-fluid/

Edited November 28, 2011 by porcupine73

[jarl]

Well... one month and a half later, I finally replaced the ATF on my car.

 

I ended up using Valvoline Maxlife Dexron, because of the price and the fact it's specified for "higher mileage" cars. I chose to go for the "one stop" procedure (the Porcupine's Way ) to avoid wasting fluid as well.

 

So... in case someone find this useful in the future, here's the report:

 

I used...

- 3 gallons of Valvoline Maxlife Dexron III

- New OEM bolt-on filter and plug crush washer

- About 4 ft of 3/8" clear plastic hose

- A 2 liter Coke bottle with a mark at the 2qt level, an empty oil gallon jug, a pan to catch the oil

- Ramps, filter wrench, sockets, etc.

 

I drove the car about 5 miles to warm the ATF a bit, and to make sure any crap that may have settled over night went into suspension once again. Drove the car into the ramps, crawled underneath it and removed the plug.

(bummer #1: the plug wasn't the magnetic one, meaning metal shavings were not being removed from the fluid). The stuff coming out of the transmission was nasty

 

I used a filter wrench (band type) to remove the filter. The filter was too small to grab it, so I got a small piece of scrap metal angle and clamped it along with the filter. Installed the new filter and the plug (18lb-ft per FSM). Added one gallon of ATF using the dipstick tube (driver's side). Then transferred the old oil to the two (empty, graduated) jugs. From the marks on the jugs, I got 5.6 quarts of used ATF out of the transmission.

 

I added two more quarts of ATF (six total) and then disconnected the top hose at the transmission cooler (on my '99 OBW the cooler is vertical and on the driver's side of the radiator). Then I connected the clear hose between the cooler and the (now disconnected) hose. Made a vertical loop with the hose, clamped it to the hood and started the car for a few seconds, until I saw ATF flowing through the hose. It was coming out FROM THE COOLER, meaning that was the return line to the transmission (the one I needed!!! if it had come from the disconnected hose instead, that would mean the return line was the one at the bottom of the cooler, which is a pain in the lower back to disconnect)

 

Then I disconnected the plastic hose from the rubber hose, and drained the oil still on the plastic hose into the coke bottle (leaving the other end still connected to the transmission cooler). And the fun began...

 

I grabbed the coke bottle with the hose still on it, sat on the driver's seat and started the car. Watched the bottle filling, stopping the engine slightly short of the 2qts mark (the oil will continue flowing a little bit). Poured the contents of the coke bottle into the used jugs, and put two more quarts of ATF into the transmission. Repeated two more times, but on the last iteration I added a bottle (1/2 quart) of Trans-X and only one quart of ATF. At this point, also, the ATF coming out of the hose was cleaner, although not 100% (bummer #2)

 

At this point I estimated I had 11 1/2 quarts of used oil out and a similar amount of new fluids in, and 1 quart of new ATF left. Reconnected the cooling line to the radiator, cleaned up all my stuff, lowered the car and went for a short drive (again, some 5 mi). And to my absolute amazement, everything seemed to work fine The delay to go into "D" has reduced a bit already. It's still not "good", but better. We'll see how does it work tomorrow morning...

 

Finally, I parked the (now warm) car in my garage, and checked the ATF level. It was slightly high, so I removed 8 ounces or so using a large syringe and a piece of hose through the dipstick tube. The fluid level still registers *slightly* high but I'll leave it there for now... until I learn how to read correctly the $%#^$ dipstick. I confirmed the oil wasn't as clear as I would have liked, but it's way better than it was originally.

 

And I was done

 

While underneath the car I saw some stuff I didn't like... the driver's side valve cover is covered in oil... probably because of a faulty o'ring on the oil filler tube (bummer #3). The bottom of the front differential is also covered with an oily grime (bummer #4) but I'd like to believe it's old (I still need to deep-clean that area). We'll see.

 

Anyway... I hope this helps. I'll keep you posted.

Edited January 7, 2012 by jarl