97 Leg GT AT Trans Problem, need clutchpack? Torque bind. RESOLVED!! UPDATED!

[johnnysubaru]

I posted a very large update below.

 

<quick update> The bottom line was a T-Tech Flush solved the problem of torque bind for this car after about 15 min of driving. Before the flush, a slow tight turn would make the car clunk and buck really bad. After the flush, not a single jump. Prior to the flush, the fluid levels were correct.

 

We did not add the LSD additive because it appears to be fixed. Should it come back, that will be our first idea. Thank you everyone for your input.

 

Hey Everyone, (UPDATED, SEE POST BELOW!)

 

My Dad has a 97 Legacy GT 2.5 DOHC with AT trans. The car is just over 100K. Recently when pulling out in a turn (right or left), the transmission is bucking. When straight it is fine. The trans shifts smooth. Its just the bucking an clunking when you put out while turning. Last night I did a test drive for him. He thought it may of been a bad CV joint, but its quite clear that isn't the issue.

 

here is what I did.

 

1. From a dead stop, made hard right turn. there was a lot of clunking and bucking until I turned the wheel straight. Same for dead stop and making left turn.

 

2. Checked AT fluid, fluid looks ok.

 

3. Checked transaxel fluid, level OK.

 

4. Inserted fuse in the FWD box to disable the AWD function. When the AWD function was disabled, the clunking and bucking stopped 100%.

 

So my guess is that there is an issue with the transfer between the front and rear wheels. My dad is not an aggressive driver.

 

Does anyone know if this is a common problem on GT's? Could it need the cluctchpack replaced?

 

If it is a known problem, is it better to have the original trans fixed or find a new one? For example, i have already located one with 32K and they want $595.00 (shipping included).

 

Thanks everyone,

keck

[cookie]

Flush it and make sure the tires are the same first. Do a search, should be a ton of info on flushing.

[Guest D1Driver]

You got what sounds like torque bind. Welcome to the club!!! My 98 Legacy OBW has it, and from what I have read, a flush may fix it, or a new center diff!

 

If the car shifts fine, you don't need an entire trans. Just the back section, about a foot long. I scored a used one on here for $45 shipped. Haven't flushed mine yet, so I don't know whether I need it or not. If not, I will look you up. I will be flushing mine this weekend.

[idosubaru]

flush the fluid first.

make sure all your tires match in brand, size, tread and tire pressure.

 

if none of that helps, then you'll start looking into replacing the trans or the rear extension housing assembly options.

[johnnysubaru]

UPDATE.

 

Here is the deal. I spoke with Darrel at Tacoma WA Subaru. I had a similar problem with an impreza i owned in the past. The fix was to actually go to a Dodge Dealer and get a bottle of Limited Slip Differential additive, cost about $10, and put it into the AT fluid. When I did that, the "binding" went away almost immediately. I thought it may be different this time so I called him again.

 

He said that about 90% of the subaru's they service with the torque binding problem is due to NOT changing the AT fluid every 30K which causes the transfer clutchpack to gum up. When they do not slip correctly, it does not allow for wheels to turn at different speeds. This is why the problem is most noticable at a very slow hard turn because the wheels on the outside of the turn are spinning faster then then ones on the inside. Similar to a posi-traction Diff. He said it is rare when they actually have to replace clutchpack (long section after the transmission). Typically the fix of a flush + the additive will fix it. The additive is mentioned on other forums as well. I also saw a reference where a GM version of LSD additive is actually mentioned on a 1996 SUBARU TSB. It will take about 250 Miles to fully work.

 

Tire pressure or tire size can also cause binding but it would have to be significant as tires are constantly changing diameter based on speed, temp, wear, etc.

 

FLUSHING THE AT FLUID - Note, this is NOT done by simply removing the drain plug on the trans pan and letting the fluid run out. This would only remove about 40% of the fluid as the rest would still be in the torque convertor, internal trans valve bodies and trans cooler.

 

To effectivly change the fluid, you must either go to a shop that has a t-tech machine that will allow fulid to be circulated through the system. Considering the mess, I'm doing to a lube place. They charge $90. But you figure you'll need about 13 qts so you're not that far off Plus then you have to dispose of it.

 

The messy way I saw described. Basically you identify the in and out lines of the tranny cooler, then use a length of hose. out goes into an empty bucket, in goes in a full bucket of trans fluid. Then you start the car, yes start the car. The car's transmission pump will move the fluid. You will need to keep your foot on the brake and move it through R, D, 2, 1, etc. Then check.

 

Another issue could be the duty solenoid C. In my case I have already tested it. In older subaru's, under the hood, against the firewall on the pass side is a small single fuse box marked FWD. This is used for when the vehicle is towed to disable AWD. When you open it, you'll see there is no fuse, you must put a fuse in there to make the car become FWD. If you put the fuse in and FWD shows on the instrument cluster AND the clunking of the binding stops, it is showing you that the solenoid is working properly.

 

Finally, in extreme cases, the clutches can actually 'weld' together. this is obviously necessary to replace the clutchpack.

 

Hope it helps anyone. i will write back with the outcome of fluid flush + LSD additive.

[Wayne Boncyk]

Nice summary! You have basically condensed into one post that which most of the rest of us have taken pages of postings to describe!

[johnnysubaru]

Is that good?

 

Nice summary! You have basically condensed into one post that which most of the rest of us have taken pages of postings to describe!

[ericem]

Is that good?

 

very.

[ericem]

Is that good?

 

now we all know what to do, thanks!

[Guest D1Driver]

Dodge dealer for LSD additive?? I really would like to know what this stuff is and/if any other kind of additive might work.

[rweddy]

FLUSHING THE AT FLUID - Note, this is NOT done by simply removing the drain plug on the trans pan and letting the fluid run out. This would only remove about 40% of the fluid as the rest would still be in the torque convertor, internal trans valve bodies and trans cooler.

 

To effectivly change the fluid, you must either go to a shop that has a t-tech machine that will allow fulid to be circulated through the system. Considering the mess, I'm doing to a lube place. They charge $90. But you figure you'll need about 13 qts so you're not that far off Plus then you have to dispose of it.

 

Be very careful where/who you have do the flush.

Make sure they machine uses the cars transmission to pump the fluid rather then the machines motor. This is what damages most transmissions is the high pressure most flush machines use. Most cheap shops quickie lube, jiffy, etc use the machines with high pressure that will ruin your transmission.

[msmithmmx]

I have this same problem. Question, If I want to rule out my duty solenoid C all I have to do is stick a fuse in the "FWD" box inside the engine compartment. What size fuse should I use?

[idosubaru]

standard blue 15 amp fuses are fine. a 10 or 20 or 25 would work fine too for testing purposes.

[johnnysubaru]

Dodge dealer for LSD additive?? I really would like to know what this stuff is and/if any other kind of additive might work.

 

LSD - Limited Slip Differential. This is typically put into the diff of a car to help with the LSD function. However, it also will free up sticky gunked clutchpacks. If you'd call a dodge dealer and ask for it, they should be able to get it to you. its in a small bottle (about 6oz i think). I've read on other forums that basically any LSD additive would work. GM has one as well as NAPA. Just so happens that the Subaru Tech that told me about it works across the street from a dodge dealership. This process is also referenced in a 1996 Official Subaru Tech Service Bulletin, but I don't know what month.

[johnnysubaru]

I have this same problem. Question, If I want to rule out my duty solenoid C all I have to do is stick a fuse in the "FWD" box inside the engine compartment. What size fuse should I use?

 

Yes, that is correct. When the solenoid is energized (you putting a fuse in the FWD box, it will stop the flow of fluid to the transfer case. After the fuse is in place, you will notice a FWD light on your instrument cluster. If you do not, then there is likely a problem with it. I've read as well that if the solenoid has a problem it will put a trouble code on the computer. So when you have the fuse in and try to drive it, if the clunking and bucking stops when making a slow sharp turn, then you know the solenoid is working properly.

 

The sub tech says that you should have your AT fluid changed every 30K. Also, if a place would offer a conditioner treatment DO NOT DO IT. Only replace fluid, no conditioners. ALSO, they should not remove the filter (looks like a standard oil filter on the side of the trans).

 

Hope it helps!

[brus brother]

This should be a sticky.... Moderator??

[johnnysubaru]

Be very careful where/who you have do the flush.

Make sure they machine uses the cars transmission to pump the fluid rather then the machines motor. This is what damages most transmissions is the high pressure most flush machines use. Most cheap shops quickie lube, jiffy, etc use the machines with high pressure that will ruin your transmission.

 

Yes, that is correct. The T-Tech machine is nothing more than a piston with two fluid reservoirs. The transmission pumps bad fluid into the one side and moves the T-Tech's piston that pushes new fluid in. The pressure is regulated by the car.

 

Speaking of which, when I had it done. The guy said that you cannot perform t-tech on a subaru because they don't have cooling lines. I laughed and got right down on the floor and basically showed him his job. It worked out fine.

 

side note, he first did what he called a flush which was nothing more than a drain & fill. That replaced 2.2 qt's of fluid. I said what about the other TEN still in the system!!! If i wasn't watching him I would of enjoyed a 20% fluid flush of which the new fuild would of been contaminated by the old fluid in about ummm. 2 seconds..lol

[johnnysubaru]

This should be a sticky.... Moderator??

 

what's a sticky?

[msmithmmx]

I think I passed out!! When I put that fuse in place should the car be off or on? That additive is added into the transmission fluid filler pipe correct? Where can I get a funnel that is small enough to fit in there? And the big question? I have a box of ATF on my garage that has been sitting for 2 years (I put this job off) is it still good?

[johnnysubaru]

I think I passed out!! When I put that fuse in place should the car be off or on? That additive is added into the transmission fluid filler pipe correct? Where can I get a funnel that is small enough to fit in there? And the big question? I have a box of ATF on my garage that has been sitting for 2 years (I put this job off) is it still good?

 

 

I'd have the car off, then put the fuse in, then start car and test, turn off and remove fuse.

 

Any car parts store should have a funnel with a long hose that would fit.

 

I don't think ATF has an exp date. Just be sure its the right type. I think its DEX-III

[brus brother]

If you look at the first page of the New Gen site there are a few sticky posts. The first is FAQ. This contains information, such as the very thorough write up in this post, that has been addressed with such eloquence that by posting it in the FAQs prevents such stalkers as Nipper, Cougar, OB97 and many more from developing tunnel carpal syndrome from retyping the same information over and over and over... did I say over and over and over...

what's a sticky?