Auto transmission slippage - 2001 Outback

[wtdash]

What the Trans shop may be referring to is when a transmission is 'power flushed' the old fluid that was actually help 'seal the seals' in the transmission may be loosened and the seals will begin to leak. I've had this happen, but wasn't warned it COULD happen and had to rebuild the transmission shortly after the flush.

 

If the transmission really is about 'dead', I'd recommend what we here on the USMB tell everyone to do: Drain>Refill>Drive, Repeat 3 times. There are approx. 4-5 qts of ATF in the trans. pan and 4-5 qts in the Torque Converter. By doing the drain>refill>drive multiple times it gets MOST of the old ATF out of the system, WITHOUT disturbing the seals, as there's no pressure involved...just gravity draining it out.

 

Drive the car for a few miles and trips and see if it's better. REMEMBER that when the ATF is changed out the transmission will shift differently as it adjusts to the new fluid....read the Owner's Manual about this.

 

 

TD

Edited August 26, 2016 by wtdash

[landolphe]

I'm still confused. I don't know what an about  "dead" trans means. It just started slipping and is driveable as is.

[idosubaru]

Option A:  Keep driving it as-is without changing fluid, see what happens?

No risk of new fluid harming anything,

But no chance of new fluid helping the current situation/promoting longevity if the trans is good. 

 

Option B:  Drain and refill it with fresh fluid. Preferrably 3 times after any amount of driving. Just like an oil change but easier as there's no filter required.

Might cause issues?

Might save the trans?

 

If the new fluid causes issues then your transmission was likely about to fail anyway...as it's presumably already doing.

 

I would stick to proven ideals of good maintenance -drain and refill it now and see what happens.

Avoiding rare and hard to verify issues like "new fluid causing problems" seems the lower percentage option in my book. 

 

If you did this 1,000 times I think yo'ud win more often choosing the fluid change.  But there's otherwise no way to verify the best choice for this exact transmission 

 

Well - you could pay a really qualified person $1,000+ to disassemble the valve bodies, measure fluid contaminants, and check for debris/possibiliies - I'd want at least $2,000 to do that myself.  But yeah, no one is going to do that - so you just have to make an educated guess.

[landolphe]

Thank you for the thoughtful analysis of the problem and my options. I agree that changing the fluid seems the best way to go. Now the problem is that no local shop is willing to change the fluid! Does the fluid's being dark color mean that it is degraded or something else? Does this reflect a longstanding, chronic condition or one of recent onset. The problem I'm having started suddenly two days ago. Of course the fluid is 15 yrs old, despite the car having only 51,000 miles.

[landolphe]

Can the minor slipping I'm having be caused by the old ATF's being degraded?

[idosubaru]

how many and who have you asked? 

 

call more places or ask around anyone you know that might know someone that will do it for you. 

if you stop in - in person - you can tell them, you're not interested in holding them liable if the issue persists or gets worse (which is likely).  they don't want to change the fluid, then have you blame them for something that was already broke or going to break no mater what anyway. 

 

i suspect if you just stop by some local oil change joints one of them will do it for you

 

Can the minor slipping I'm having be caused by the old ATF's being degraded?

 

of course.  you "can" get hit by a meteor in the next 16 seconds.

 

i think the most accurate way we can put this, with what little we know is:

1.  there's a high probability that the fluid condition has caused the current shiting issues. 

2.  wether that's a fluid issue, mechanical issue that was caused by the fluid, or a combination of both, (which determines if fluid changing will help) - is probably hard to guess. 

 

 

I think it's rare to see dramatic changes in AT issues with fluid changes only - but sometimes it happens.  4WD components in clutch packs can be freed up with fluid changes and it's far less intense than swapping transmissions so why not try it?

 

 

 

[landolphe]

I am a very old man and my eyes aren't great, so I had two of my grandchildren look at the ATF dipstick. They agree that the fkuid is NOT black or dark, but is a light RED color and does not appear to read low, but there was disagreement cuz we checked it COLD and the stick was filled to upper mark in HOT range.

There's a 10A fuse for the Automatic Transmission Control Unit. Does not appear to be blown.  What does this control unit do?

 

Given this revised info re ATF (sorry for my mistake), what else might be the cause of the problems? What should I do/check next?

[landolphe]

Could the Differential and/or its fluid level be implicated here? I'm clutching at straws, you can tell!

[idosubaru]

1. read the check engine codes (free at any national chain) - maybe this is engine related and not transmission (they're easily and often confused - happens all the time)  really need a quality diagnose to help over the internet - is tis engine or transmission? 

have someone else drive it and ask them?

2. Some H6's have TPS issues that cause erratic shifting, but I don't think it usually cause slipping that I know of.  i doubt this is your issue, but TPS replacement is the cure for those with erratic shifting.

3. check the transmission pan and make sure it's not dented.  it'll restrict fluid uptake internally as the clearance between the pan and sump are tiny. 

4. change the fulid - on an unknown vehicle, it's not a bad idea.   

 

So the fluid is slightly overfilled?  those readings are hard to get accurate, they're really annoying sometimes.  That shouldn't cause an issue - but go ahead and get it to the right levels if you're having issues and you know it's high.

 

the ATF control unit is the computer for the transmission.  we can tell the fuse isn't blown or it wouldn't shift at all.

[idosubaru]

We are still unclear what the symtpoms are which makes it tough if we can't see, touch, drive, or smell the car - but a front differential most definitely does not cause slipping, or sound like what you're dealing with.

 

Actually a front diff can cause slipping but if you're not embarassed or scared to drive it, it's not the front differential, it would sound like this:

 

 CLACK CLACK CLACK GRRRRRRR, CRICKETY CRACKETY SLACKETY BAM, CRIKEY WONKY KABASH....

[idosubaru]

follow my steps above and i think that will help us help you.  

 

#1 and #3 are really easy - they're free, easy, and only take driving to an auto parts store and looking at the trans pan.  the friendly auto parts store person can even probably eyeball the pan for you. 

or post a picture on here. 

or print my steps out and ask them to test #1 and #3 above for you. 

[landolphe]

I have a friend who has the computer to read the various codes. I've never felt a slipping transmission before, so I have no referent for what I'm experiencing. It "feels" like the engine is hiccupping in forward gears. There is no racing of RPMs and no unexpected change of gears.

 

It always shifts forward gears sequentially without any downshifting. Only when going from Park to Reverse is there a metallic clackety sound and vibration. Goes into Reverse OK and drives in Reverse OK.

 

When stopped and in drive, the engine seems to idle faster and rougher. Racing gas normalizes this.

[landolphe]

It has been suggested that the problem may be with the engine computer not the trans. Hopefully, the code check will clarify this. Meanwhile, I have no option but to keep driving as is.

[shoebee2]

As the nternals wear microscopic particles begin to collect in the fluid. This is normal and why you are advised to change the fluid every 33k or so. If you don't change fluid that particulate matter builds up causing accelerated ware. Once you e passed a certain percentage of particulate matter to fluid, and have begun to see signs of criticize ware, the additive particulate matter begins to act as a binding additive. To give you an example, you can buy fluid additives for high mileage transmissions to give you a few 1000 extra miles before it dies. Typically these fluids have pecan dust added to increase the frictional coefficient of the fluid. Friction is what allows the plates to bind to their viscous clutches. More grip, longer life for worn plates.

Sooooooo to make a long story even longer......

You put brand new fluid in that has no particulate matter in suspension, you have just lost a lot of friction for worn parts.

 

If you do change the fluid, and I would probably do so for two reasons, add a high mileage binder to replace the particulate matter your loosing with the fluid change.

 

The reason I would change the fluid, and this is just my opinion and I don't know squat.

Trans fluid and a viscous count. Just like eng oil and every other libricant. As it ages that count begins to break down. It doesn't break down completely but it does loose efficiency. It flows faster, gets thinner and is more prone to sledging under load and temperature. Some of the galleys and passages are excreamely small inside the valve body and depend on a specific viscous property for both flow AND pressure.

The other reason I mentioned but it's important to know that once a synthetic, dex 3 is synthetic...all trains fluids are, begins to break down it will separate out paraffin (we say sludge). That will clog those very small passage ways. Not completely right away but partially making the entire situation worse due to starvation and cooling problems.

 

Using an additive is better. Additives are no corrosive while increasing viscosity and fiction. Old metal and rubber particulate is adding grip but is also very corrosive.

[idosubaru]

It has been suggested that the problem may be with the engine computer not the trans. Hopefully, the code check will clarify this. Meanwhile, I have no option but to keep driving as is.

 

I sort of figured that out without even looking at it - that's why i recommended it in step 1 above, i was starting to think this diagnosis is questionable and we need some good description/information to go on. 

 

although specifically speaking it's not the "engine computer" that's the problem.

 

the code readers are FREE, FREE, FREE at Advance Auto Parts, Autozone, NAPA, and many other national chains.  you show up, ask them to read your code, and write down the number they give you and post it here.  that would take less time than typing these two pages of threasd.  you don't need a friend with one.

 

*** Is the check engine light currently on?

[WoodsWagon]

What's the clackety noise you're hearing? Is it just one clack when you shift reverse to drive it does it keep clattering until you start accelerating? Does the transmission hold the car on a hill when you put it in Park? Or does the car roll away?

 

A broken axle CV joint or any other driveline component between the transmission and any of the wheels will feel like a slipping trans as the AWD system tries to compensate. Accelerating harder makes it less noticable because the AWD is programmed to lock up when you do a fast start for greatest traction. Easy slow starts will show the most slippage.

[landolphe]

Only a couple of times did it make a grinding noise when going from Park to Reverse, but even then it drove smoothly in R.  That noise has stopped! The hesitation I feel is most noticeable when starting out with a good bit of acceleration. Starting out slowly, it passes through the gears with little or no noticeable hesitation, even though the gear changes are not as silky smooth as before, and I can feel/hear them "slot" into place.

 

The Check Engine light is never on. I do know that there is a problem with the clock spring as the horn doesn't work and the Air Bag light is constantly on. I assume that's an unrelated problem, but then again I know almost nothing about any of this. I appreciate the kind patience and assistance I have received from everyone in this forum.