Tranny fluid change, comments to those that haven't done it

[Allpar Mod]

I decided it was time to change the tranny fluid on my '99 OBW as the delayed shifting thing started rearing it's head again. If you haven't done one, or are hesitant to do it, do it. It's one of the simplest swaps you will ever do.

 

First, on this particular tranny, you do get the lion's share of the fluid just by draining it with the drain plug and removing the filter. What is a good idea to help this is to jack up the car with the driver's side slightly tilted down as the drain plug is on the driver's side. This helps promote a more complete draining of the old contents. I'm used to this NOT happening short of having the transmission flushed by machine. The less of the old, contaminated fluid that remains, the better it is. Having a drain plug is not that common among automatic transmissions, front or rear drive. Normally, the pan has to be dropped and requires replacement of the pan gasket. Here's a cost savings right off the bat.

 

The spin on filter is another great innovation. The only gripe I have is the cost. Pep Boys charges $25 for a Purolator! I have no clue why something configured like a $3 oil filter is so damn expensive.

 

For under $60, including a bottle of Trans X, you can add life to your automatic tranny. It shifts correctly now and I can swear that it shifts under motion a bit smoother also. It also took me under 30 minutes to complete the whole change and used just a socket set for the drain plug and a big pair of channel locks to remove the old filter. I put a lot of miles on my cars and a bit of prevention goes a long way. For you guys that do primarily city driving, this is even more essential. Heat, which is worse with stop & go driving, kills a tranny faster than anything.

[lmdew]

To get most of the fluid most recommend a drain and fill 3 times with short drives in between.

 

I like to pull the trans hose going to the radiator. Drain and fill the trans, the with the hose going into a gallon jug, start the car. The trans will pump out the old fluid.

 

Do about 2 qts at a time. Keep on filling the trans, start it back up and let it pump out some more. When the nasty dark fluid turn bright red, you are done getting the old fluid out of the trans.

 

Hook the hose back up and service to the proper level.

 

There is NO need to drop the trans pan to get at the screen filter in there, it's just a screen.

[jdemaris]

I decided it was time to change the tranny fluid on my '99 OBW as the delayed shifting thing started rearing it's head again.

Pep Boys charges $25 for a Purolator! I have no clue why something configured like a $3 oil filter is so damn expensive.

 

If you've got the 4EAT Jatco/Mazda trans, a new filter kit at Rock Auto is less then $5.

 

I wonder why your trans started shifting slowly before you did any work? Regardless of what some owner's manuals recommend, many cars get driven over 200K miles, never get a trans-oil-change, and work fine. If changing your filter somehow improves it, then something is getting in the filter that shouldn't be there anyway. Lockup-clutch debris or something?

 

In fact, in some applications where Ford uses that trans, they don't recommend any oil changes unless a problem is suspected, e.g. slow shifting, bad looking or smelling oil, etc.

 

My 95 Impreza has 245K miles with auto-trans and has never had an oil or filter change. I start it and drive at temps down to 25F below and it still shifts fine - so far. At this point, if the trans started to go, I'd probably junk the car and stick it up in my field with the other dozen Subarus. The oil on my Impreza's dipstick has also been clear and never smelled burned. So for me, no reason to mess with it. I've had to replace every wheel bearing on it at least once (did the rear twice), but the 2.2 engine and the auto trans have been bullet-proof.

[davebugs]

I do the drain, fill, drain, fill, drain, fill method.

 

Last one was the GF's 2006 Impreza. I believe I used a total of 14 qts of Wolfs Head Universal Synthetic. I created a thread at the time.

 

I was trying to do a drain & fill every second or third oil change.

 

A lot of us in a variety of vehicles have had tranny troubles after servicing a long neglected tranny. It's happened to me after trans lines have blown for instance. Do you drop the pan, change the filter, or just add fluid. I've had better luck w/Chevy's just adding the fluid if I didn't know the service history.

 

On the used Astro vans I buy I've tkaen to using sucky toy (Pella) and every other year or so sucking out about 2 quarts and replacing with a bottle of Lucas and toping off with tranny fluid.

 

My VW TDI as "lifetime" fluid. I don't trust it. I do it every 60k or so.

 

It seems that if a tranny had long been igonored, that it's better to continue that treatment. It's the only thing I know of that seems that way. Where maintenance could actually possibly be bad if it had been ignored long enough.

[vasy]

Mine is a 96 OBW auto AT. Never had any issues with AT. I drain and fill every 30K miles. Never dropped the pan. But I found out that I can drain close to 7.5 qt if I jack up the right side of the car by positioning the floor jack's saddle at lower control arm's bushing clamp near the cat, jacking up as high as I feel safe without tipping the car, leaving the car in that position for 2 to 3 days (> 48 hours). It'll keep dripping from the drain hole on the pan. I did this way twice and measured 7.4 to 7.5 qt both times. Much less fluid drained if I didn't jack up the car this way. Owner manual says total capacity is 8.3 qt for 2.5 AT. That's a lot of fluid coming out without doing a flush. I didn't bother with AT hose at radiator and my car does not have an external filter.

[Mike104]

The spin on filter is another great innovation. The only gripe I have is the cost. Pep Boys charges $25 for a Purolator! I have no clue why something configured like a $3 oil filter is so damn expensive?

 

Here is a link to a thread that discusses the ATF Spin On filter.

 

http://www.subaruoutback.org/forums/66-problems-maintenance/23762-subaru-transmission-filter-different.html

 

I bought mine from an online Subaru dealer as I was only going to change it once.

[Rooster2]

Here is a link to a thread that discusses the ATF Spin On filter.

 

http://www.subaruoutback.org/forums/66-problems-maintenance/23762-subaru-transmission-filter-different.html

 

Good info regarding trany filter vs oil filter. Yea, I can understand the differences, but for so little difference, why is the cost differential so great. Cost is like 10X or 15X greater then oil filter. Guess it has something to do with small production runs, and low volume sales.

[Allpar Mod]

It seems that if a tranny had long been igonored, that it's better to continue that treatment. It's the only thing I know of that seems that way. Where maintenance could actually possibly be bad if it had been ignored long enough.

 

Being around cars as long as I have been, I've heard this philosophy before many times. There likely is some merit to this from what I've seen. Still and all, when there is some issue looming, you have to look at doing something. In my case here, the delayed shifting issue is fixed and overall is working quite well. The good thing was that there was no overall shift issue or operation problem, just the delayed shift which has been commented on a lot in other threads. One mistake I made after I bought the OBW last year was to add the Trans X without doing a full fluid swap because I liked the appearance of the fluid. I was told here then that I should have better swapped the fluid and the advice was correct.

 

Sometimes you have to take a chance on a neglected component. The end result is not always bad. One example is after my father in law passed in 2001, we had his '89 New Yorker with only 28,000 miles on it. I started using it to go back and forth to work. I noticed that it shifted terribly and after looking at the dipstick, the fluid was nearly black. I went to Jiffy Lube and had a flush done with a new filter. The car immediately started shifting like new again. The car is still around in the family and shifts just fine.

[wtdash]

One example is after my father in law passed in 2001, we had his '89 New Yorker with only 28,000 miles on it. I started using it to go back and forth to work. I noticed that it shifted terribly and after looking at the dipstick, the fluid was nearly black. I went to Jiffy Lube and had a flush done with a new filter. The car immediately started shifting like new again. The car is still around in the family and shifts just fine.

 

After losing Reverse when I had my '95 Legacy's 4EAT Flushed (to address torque bind), I'm hesitant to recommend a flush on any Subaru over 100K that's never had the AT fluid touched. I'm in the drain>>refill 3x camp.

 

Is it a valid argument that a flush can dislodge old fluid deposits leading to leaking seals?

 

I don't know what a flush does internally, but if applies a reverse, or higher-than-normal, pressure to the AT's internals, I can see it being an issue.

 

Thanks,

Td

[2001outbackwag]

I am seeing allot of information concenring Dexron III has been replaced by Dexron VI. Is this ok to use in Subaru tarnsmissions that specify Dexron II or III?

[OB99W]

I am seeing allot of information concenring Dexron III has been replaced by Dexron VI. Is this ok to use in Subaru tarnsmissions that specify Dexron II or III?

Citgo says, in the "APPLICATIONS" section of http://www.docs.citgo.com/msds_pi/10165.pdf :

"DEXRON-VI is not suitable for use in non-GM vehicles which called for DEXRON-II or DEXRON-III type fluids."

 

Although other Dexron-VI suppliers don't agree, I'd stick with III to be safe.

[WoodsWagon]

A lot of us in a variety of vehicles have had tranny troubles after servicing a long neglected tranny. It's happened to me after trans lines have blown for instance. Do you drop the pan, change the filter, or just add fluid. I've had better luck w/Chevy's just adding the fluid if I didn't know the service history.

 

It seems that if a tranny had long been ignored, that it's better to continue that treatment. It's the only thing I know of that seems that way. Where maintenance could actually possibly be bad if it had been ignored long enough.

The reason for that is the amount of deposits and gum built up inside the transmission by using old fluid for so long. ATF has a lot of detergents in it's additive package, so when you replace the fluid the new fluid does a great job of breaking loose all the gunk inside the tranny. That gunk gets caught by the filter, overwhelms it, and the filter clogs. The pump starts cavitating because it can't pull fluid through the filter and line pressure drops off. Low line pressure leads to low clamping force on the clutches and bands, they start slipping which releases more friction material into the fluid, clogging the filter more, and it's done.

 

Filter changes are crucial once you decide to change the fluid. On a transmission with a paper or felt style filter (like most domestic ones) you need to change the filter multiple times when you switch from neglect to proper care.

 

Honda's have non-replaceable filters, you can change them once you dissasemble the case to rebuild them, but otherwise not. I've seen lots of their transmissions limping along with low line pressure due to a clogged filter. It's really stupid engineering.

[davebugs]

I've seen folks change the filter and use the old fluid to try and minimize this exact issue. That's the idea behind me sucking out some fluid every 2 years and adding Lucas ATF additive since my van is typically dedicated to towing. However I seen to be a bit of an expert on lowing tranny lines while towing and loosing a lot of fluid.

 

FYI I have also seem the exact same behavior when folks with diesels switch to high bio-diesel mixtures. Often they are bright enough to change the rubber fuel lines, but forget about all the crap in the fuel tank and system that is gonna become mobile after the bio effects it. They need many fuel filters over the next short period of time.

[bulwnkl]

Citgo says, in the "APPLICATIONS" section of http://www.docs.citgo.com/msds_pi/10165.pdf :

"DEXRON-VI is not suitable for use in non-GM vehicles which called for DEXRON-II or DEXRON-III type fluids."

 

Although other Dexron-VI suppliers don't agree, I'd stick with III to be safe.

 

I understand, but on the other hand, there's no such thing as Dexron III any more, so you aren't able to do that. To compound things, a great many of the formerly-licensed Dexron III fluids changed their formulations once the Dex III program was shut down.

 

Personally, I'd suggest almost any 'universal' ATF off the shelf, or Schaeffer 204SAT, although personally I prefer the shift feel of the newer Subie fluid in my Baja.

[OB99W]

I understand, but on the other hand, there's no such thing as Dexron III any more, so you aren't able to do that. To compound things, a great many of the formerly-licensed Dexron III fluids changed their formulations once the Dex III program was shut down.[...]

My post in this thread concerning Dexron-VI was in reply to 2001outbackwag. It was sort of a continuation of the thread he previously posted, where his question would probably have been more on topic. See:

http://www.ultimatesubaru.org/forum/showthread.php?t=117922

You'll notice that I'm well aware of Dexron licensing and related issues. I suggested sticking to "III" (meaning MD-3, DM-3, or whatever is equivalent) as opposed to Dexron-VI, which may not be a good choice.

[bulwnkl]

I agree, but that brings up the question I've asked many times on various forums, with nothing but silence from those in the industry who are in a position to address the question:

 

GM, who designed and licensed Dex-III, and owned a significant portion of Subaru previously, recommends Dex-VI as a replacement for the A/Ts they designed to run on Dex-III. They knew that Dex-III sheared very quickly to the viscosity that Dex-VI starts as, and they designed Dex-VI to not shear much at all. So, after several thousand miles, Dex-III and Dex-VI are more or less the same thing (though Dex-VI is better in terms of oxidation resistance and other things).

 

Subaru, on the other hand, stuck with a Dex-III viscosity range for their new fluid. I do not know whether it shears as badly as Dex-III did, but I expect it is similar. They really only changed in order to slightly change frictional characteristics for their new trannies. A jaded person might also suggest that they made a tiny change in order to force people to buy products with their name on it, too, but that's a separate issue. Subaru recommends their new fluid for former Dex-III applications.

 

So, which is the best advice? The advice from the people who designed the spec, and whose fluid the Subie tranny was originally designed for? Or Subaru, who wants you to use a new fluid for a new tranny with very slightly different shift qualities? Or, should you stick with something that says Dex-III but is likely no longer the same fluid as it was when it was a licensed product?

 

In any case, I understand where you're coming from.

[OB99W]

[...]So, which is the best advice? The advice from the people who designed the spec, and whose fluid the Subie tranny was originally designed for? Or Subaru, who wants you to use a new fluid for a new tranny with very slightly different shift qualities? Or, should you stick with something that says Dex-III but is likely no longer the same fluid as it was when it was a licensed product?[...]

Good (assumedly rhetorical ) questions. Unfortunately, I suspect the lack of industry "reponse" is a means of ducking "responsibility". Since the issue doesn't affect current production vehicles, if anyone chooses the "wrong" ATF for an older car and has a trans problem related to that choice, there's really no accountability. "Sorry, but our fluid meets specifications, your transmission failed due to its age/mileage."