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torque bind???how difficult is it to replace the rear transmission housing?


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I have a '95 legacy wagon lsi. its an awd 2.2 sohc automatic with 165k. it has started exibiting symptoms of torque bind. i'm now wondering what is involved with replacing the rear transmission housing as this seems to be the best solution http://www.legacycentral.org/library/torquebind.htm does this part need to be ordered from a dealer? how difficult is it to remove/install a new rth? is it worth it to try and find a used unit from a newer legacy? i understand the problem was remedied after 97? would i be better off just buying a new unit? i also have access to the transmission from a '99 2.2 auto legacy. would the rth from that car be compatible with mine? any info would really be appreciated thank you!

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it has started exhibiting symptoms of torque bind.

 

Ok, we know the signs, is there a transmission failure shown (by the flashing light on start-up)?

 

Generally the accepted first thing to try is a transmission flush, that is 3, yes 3, transmission oil changes. The torque converter has no drain plug, so it takes 3 changes over a time period (a week) to effectively change the transmission oil.

 

This is the first thing to try before getting into it.

 

I have an auto transmission here with 300,000 miles on it that I will be getting into next year, but haven't had to yet, regular service is the key, along with identical tire size and pressure.

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it doesn't have the flashing light upon start up and i have had the transmission flushed to no avail... does anyone have any info as to the complication/difficulty of replacing the rear transmission housing? would a used unit from a 99 unit suffice? or is it better to oder a new one from subaru?

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How bad are your symptoms? A transflush (not a drain and refill) with additive can fix this if in the early stages.

 

If it is that bad it it fairly easy to do. Drop the exhaust, drain the trans, remove the drive shaft, put a jack under the pan, remove the crossmember, mount and exhaust bracket, lte the trans hang down, remove the speed sensor and then it is just the bolts that attach it to the trans and be careful when removing that you don't break the connector for the C duty. Once removed be careful to note where the park pawl and the bearings are all placed..... don't let them just fly apart!!!!

 

Once everything is apart start inpecting the parts. Check the C duty sol. for proper resistance, check the housing where the output shaft goes for any grooves cut into the bearing journal by the seals and check the clutches for play. If any of these are bad you must replace. You will also notice where the clutches ride on the hub you will see some grooves cut in, it is hard to explain how bad too bad is.

 

The 99 will not work if it is an external filter trans, any will work from an internal filter setup from an EJ car. If you would like you could pm me if you have any further questions or need any good used parts that may be hard to come by.

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Generally the accepted first thing to try is a transmission flush, that is 3, yes 3, transmission oil changes. The torque converter has no drain plug, so it takes 3 changes over a time period (a week) to effectively change the transmission oil.

 

You could flush the torque converter by pulling one of the tranny cooler lines, putting a hose over the fitting on the cooler, and a bigger hose on the one that you pulled off the cooler and run them both into a bucket. Pour ~4 quarts of atf into the tranny dipstick tube, have someone start the car, and watch the lines that are going into the bucket, and whichever one is pumping fluid, as soon as it starts sputtering, have the person inside shut the car off. Repeat until clean fluid comes out. Thats how we do it at the shop I work at, and this method works great.

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It's not difficult to replace the housing, the key is "clean" and do not use silicone sealer.

From Legacy Central:

The rear drive shaft and exhaust rear of the Catalytic Converter have to be removed and the rear transmission housing needs to be removed. As you remove the rear housing there is a wire to unplug from the duty C solenoid (it's an inline wire connector).

If you are assembling a bare housing the clutch pack can be tricky, if replacing with used try to get one from a low mileage/unburnt transmission oil donor, new is good, but expensive.

On re-assembly silicone is to be avoided, instead use something like this:

http://www.permatex.com/products/automotive/automotive_gasketing/anaerobic_gasket_makers/Permatex_Anaerobic_Gasket_Maker_b.htm

(offered as an example only, there are many available from different manufacturers)

carefully cleaning all mating surfaces first (razor blade, and making sure they are oil free).

And, yes a used '99 unit will fit/do, provided it has low miles and comes from a transmission that isn't burnt up.

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since nipper is off resting his back, i'll say it. make sure all your tires are the same size, equally inflated and aren't worn badly. trhis is the first and easiest fix.

if you have an AT temp light flashing 16 times at start up and torque bind, then you have a bad duty c solenoid and it need to be replaced( along with 2 duty c gaskets, $75 on line) and it can be done in the drive way. or 300$ at a shop.

 

the other causes are:

gunk in the duty c area of the fluid flow. this sometimes can be cured by changing the fluid, it may take a little while for the cleaning to take effect, but if it hasn't worked yet it probably won't. this is prevented by regular fluid changes. i guess it is conceiveable that removing the duty c and fluid lines and cleaning them would correct, but you wouldn't know until you put it back together and if it didn't you'd have repeat all that labor again, so replace in stead. ( i wonder if the crud contributes to the leaking mentioned below?)

 

fluid leaking around/between a bearing? seal? and the aluminum housing where it shouldn't. this is mostly in pre-97 trans and was corrected in 97 by adding a pressed? steel? somthing or other for the bearing to seat into which prevents wear to the housing and therefore leaking. i'm not real sure how this contributes to torque bind, but you have to replace the housing to correct this problem.

 

also the clutch plates can wear grooves into the driven drum which can contribute to torque bind. there is a great write up on the fix, but if you can get a good used unit ( if you are high mileage and pre 97 it might be best) i would do that. new dutyc in good used unit is optional, but for 75$ i'd do it. i have sworn never to install and old duty c again.

 

my 95 leg had very minor torque bind for 95K miles (75k to 170k) only on the tightest of turn. i was unaware that it was a problem, i just didn't know. (if you can feel your trans shutter when you shift into P after parking in a tight space, that's the binding being released. mine was so concerning i would shift into N for a second, to release the binding, before shifting into park.) finally the rear output shaft seal blew out of the trans, i assume this was transfer clutch related. the resulting loss of fluid cost me reverse. i swapped in a trans and it lives!!!! again.

 

when i bought my 97 OBW with 98k miles, it had torque bind and the flashing AT light. i replaced the rear housing with a good used unit (already had it ) and 285$ labor. and it lives!!! in hind sight, i should have installed a new duty c just to be sure. it wuold have added 75$ to the cost.

 

PS Edit: if you can get a good used trans and install it with a new duty c, that might be the easiest way to go. i guess it all depends on price. most yards are reluctant to sell the rear housing off a good trans. you might look for a rear housing off of a bad trans, or 'parts only' or 'core' trans.

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Alright, well i JUST did this in my impreza so i'll give you the lowdown.

You yank the exhaust (from the block, or just after the header) (don't forget the 02-sensor connector)

Pull down some heat shields

Yank off the drive-shaft cover thing (skidplate-esk... has 6 bolts, back by the rear diff)

pull the drive shaft & center bearing

while you've been doing this, you should have been draining the ATF out of the tranny

it also helps to have the car about 3ft in the air.

now support the buttom of the tranny (if you support it on the pan, make SURE you use some sort of force distribution device (aka 2x4), as to not dent/crush it). once the tranny is supported, pull off the tranny mounts from the car, and the tranny.

There is a temp sensor on the right hand side of the read extension housing (right side if you're under the car, looking towards the front)

pull that sensor out, lower the tranny a little (but not all the way, you don't want to piss-off the engine mounts that much.)

now start pulling out the bolts that hold on the rear extension housing, they're all 12mm, and i think there's 12-14 of them.

Lots of ATF will come out there, so make sur eyou have something in under there to catch it.

To get the rear housing off, it can be tricky, you can try to hammer a screw driver into the seem between both parts, just don't hammer INTO the tranny (go along the edges).

once you get the rear part loose start pulling it out.... STOP! make sure you dis-connect the duty-c solenoid wire,.

Ok, now pull it off, watch out it's sort of heavy.

make sure you don't drop any of the loose bearings or anything into the drain pan... If the shaft that goes into the clutch packs doesn't come out, pull that sucker right out, because you're going to need to do it anyhow later on. there is a bearing between the shaft and the inside of the clutch area, so you can drop it easily.

So, now you have it out,

Yank the solenoid, and the thing under the solenoid (don't break/bend the tube going into the bottom valve assy), and you'll need a new gasket for the bottom of the valve assy.

So put in the new parts, make sure you get the gasket in there, and that you ground the solenoid.

Now for the fun part, that shaft you pulled out of the tranny has to go back into the rear extension housing.

i found that that's the easiest way to do this is to get a really small flat head screw driver, and line up all of the clutch plates. Once you get them all perfectly lined up, put the bearing in the rear housing part, and then carefully lower the shaft into it, it might take you a few times to make sure it is FULLY seated (read: too me 5+ hours, took girlfriend 2 times... grrr....)

So now that you have that shaft in, DO NOT TAKE IT OUT!!! (or else you'll have to re-do it.)

So now clean up all the mating surfaces real nice, and put some copper rtv on the rear extension housing part. Now you can shove the rear housing back into the tranny, make sure you connect the solenoid wire, and get all the park stuff in sync.

now, slam that rear housing back onto the tranny, MAKE SURE you don't pinch the wire!!!

It's also a pain to get the gears to line up, put the tranny in neutral, and start hammering the the back end of extension housing, until its flush.

Now you can throw all of those bolts back on there, and all of the other junk that goes under the car... AND AWAY YOU GO!!

ish

or something.. that's about it.

Pics of the inside of the tranny, and stuff.

http://s121.photobucket.com/albums/o206/AgentBCOC/4eat/

 

I got my parts from Jamie at geniunesubiparts (not exactly how it's spelled), i think the solenoid was 68 bucks, and the gasket.. well i ordered the wrong part, the oil seal is the thing in the back, the gasket.. well you can have them look it up...

 

Oh yeah, the grooves in the drive drum there, you can use a file to flatten them out if you can't find a donar shaft.

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