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2008 OBL 158K tranny is starting to slip


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I have been told that only the dealer can rebuild this type of transmission, maybe because of the VDC.  Is this true?  I want to drive this car for another 150K miles, so I try to get ahead of problems.

I believe that I have a ACT4, part number 31000AH310, the tag says TV1B8MFEBA, 959763, U5U6,  it has SportShift.  

Will other transmissions work?  I have found units where only the last three digits of the part number are different.

LarryK

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16 hours ago, LKalenda said:

I have been told that only the dealer can rebuild this type of transmission, maybe because of the VDC.  Is this true?  I want to drive this car for another 150K miles, so I try to get ahead of problems.

I believe that I have a ACT4, part number 31000AH310, the tag says TV1B8MFEBA, 959763, U5U6,  it has SportShift.  

Will other transmissions work?  I have found units where only the last three digits of the part number are different.

LarryK

Dealer doesn't rebuild these and you don't want a trans shop to do it. 

Have you tried changing the fluid and making sure the transmission pan isn't dented and starving the pump for fluid?

You could also see if your symptoms mirror valve body issues which happens sometimes.  If that's the case - you could attempt (or have a shop attempt) a valve body replacement instead of full trans swap. 

Finding a list of interchangeable transmissions is usually not possible unless you're lucky. It's not as simple as it used to be. And also they don't fail, and aren't replaced, often enough that we have massive databases for the variety of year/make/models. For the matching final drive ratio, and other reasons, you'll almost certainly be limited to non-turbo OBW's from 2005-2009, and VDC at that. I'm not familiar with any technicalities of 2010-2013 models. 

The best source is: 

1. Go to an online subaru parts retailer and look up the transmission for your year/make/model

2. click on the "Other Vehicles" tab and it'll show you all the years and models that transmission is used in. 

Then search for that transmission. 

And also plug in your vehicle at www.car-part.com

Some of the JDM suppliers may be able to help you as well, and they're prices are good, though that has it's own level of confusion, but people have installed JDM transmissions in VDC north american Outbacks. 

There is usually a far wider range of vehicles the transmission is compatible with than is listed by Subaru, which is what you're getting at.  But it's not usually easy to figure out in these later model vehicles. 

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I have tried changing fluid by draining the pan, refill, drain, refill, about four times.  Fluid looks good.  No dents in pan.  

I have found that driving in the Sport mode reduces/eliminates the slipping.  

Is there a filter inside the transmission?  If there is, I am considering having a shop pull the pan, change the filter and perform a complete fluid change.  The suggestion of the valve body replacement (which I know nothing about at this time) might be a good idea.  I will talk to the shop.  

I am currently keeping an eye open for a 31000AH310  TV1B8MFEBA from a low mileage car that was well taken care of.  With low miles (80K to 90K).  If I find one at a good price I might just buy it "just in case".  

LarryK

 

 

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30 minutes ago, LKalenda said:

I have found that driving in the Sport mode reduces/eliminates the slipping.  

I'm not well experienced or versed in technical internal guts of transmissions, though I have mostly dissembled a few and done some internal repairs.  But that sounds electrical or in the valve body.  A filter won't help that. 

 

31 minutes ago, LKalenda said:

I have tried changing fluid by draining the pan, refill, drain, refill, about four times.  Fluid looks good.  No dents in pan.  

I have found that driving in the Sport mode reduces/eliminates the slipping.  

Is there a filter inside the transmission? 

 

 

Good job knocking out those simple checks first.  Did you (or shop) notice any swirls or debris in the fluid during changing?  Almost always the answer is "no". 

There's an external filter in the passengers side fender well area - remove wheel and plastic cover and it sits behind there.  Subaru OEM filter is ideal. Screw on, screw off (though they'll be really tight due to age, heat cycling, etc.  I would replace it with a new trans, so it's no harm in trying it now just to see, but i doubt it'll help.  They don't really "clog" and easily last the life of the vehicle more often than they do not. 

Technically speaking there is a "filter" inside the pan - but it is pointless to touch it.  It's a very generic screen, that's it,. They're perfectly clean at 200,000 miles even on older Subaru's that never had AT filters, or in failed transmissions upon disassembly.  I've seen minor debris on them, but if one of those screens has debris in it such that it's causing problems - the trans is absolutely hosed and would have egregious symptoms. 

 

30 minutes ago, LKalenda said:

Is there a filter inside the transmission?  If there is, I am considering having a shop pull the pan, change the filter and perform a complete fluid change.  The suggestion of the valve body replacement (which I know nothing about at this time) might be a good idea.  I will talk to the shop.  

 

Some 2005+ subarus seem to have more frequent valve body issues than earlier models, so it's worth looking into.  I'm not sure how to diagnose, though I think slipping is a common refrain, an online search would definitely reveal symptoms people have. 

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12 hours ago, 1 Lucky Texan said:

You could try something like Trans X, but I have only read of it helping with 'delayed engagement'.

As Click and CLack would say, you get to go to the back of the auto parts store and try all the transmission additives. At this point it can hurt.

 

Once a tranny starts slipping its impending doom. Usually at the most inopportune time

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14 minutes ago, LKalenda said:

Okay, enough constipation on making a decision.  Rebuilding is out, valve body is too iffy for me.  I will look for a used transmission with 80K or less on it and buy it.  Thanks for the advice.

LarryK

Yeah man that's what most of us would do - you did the right thing looking into fluid, pan dent, and asking here for any generation specific hang ups. 

www.car-part.com

With the population of CA there should be zero issues finding a trans. 

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49 minutes ago, LKalenda said:

Okay, enough constipation on making a decision.  Rebuilding is out, valve body is too iffy for me.  I will look for a used transmission with 80K or less on it and buy it.  Thanks for the advice.

LarryK

Always better to do it on your timeline then the cars.

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Here is what happened.  I bought the correct transmission from Parts Market.  A day later they replied that they did not have the part.  Fortunately, I got my money back within 24 hours (buying through ebay probably helped).  I am looking at another part from a auto wrecker in MI.  See what happens.  LarryK 

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