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Easy Transmission Front Seal Replacement


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Can anyone tell me if this seal can be damaged when installing the engine? After doing the clutch, this 97 2.5 was leaking gear oil from the bell housing. From the pictures, I can't see it happening, but I will defer to the experts.

 

Can't really damage it installing engine......UNLESS it's a dual range.  Dual ranges have an extra bearing support assembly right at the front.

 

Dual ranges, if the input shaft isn't aligned right, and you force it.......you can force the bearing to blow out the clip in it's retainer.

 

BUt anything single range I can't see how engine install could hurt it.

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The only problem I see with this seal is that it was running crooked. I don't have a good enough camera to get pictures, but the witness wear marks on the seal lip show a wide wear pattern on one side and a narrow -almost non-existent - wear pattern on the other side. So i guess it's imperative that the seal is seated square in the bore when reassembling?

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I have a question.. each time I pull my motor I got what looks like black grease all on the engine crossmember, does the front seal only leak when the engine is running? The funny thing is when pulling the motor I can't detect anything.. and I noticed the same leak pattern on the stock and replacement transmission.

 

Also I haven't touched the front seal, replacement transmission had 85K on it.

Edited by 1-3-2-4
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  • 2 weeks later...

I have a question.. each time I pull my motor I got what looks like black grease all on the engine crossmember, does the front seal only leak when the engine is running? The funny thing is when pulling the motor I can't detect anything.. and I noticed the same leak pattern on the stock and replacement transmission.

 

Also I haven't touched the front seal, replacement transmission had 85K on it.

The front seal only leaks when the car is moving forward. The ring gear of the front diff slings oil up onto the back of the seal as it spins.

 

Sly, if the trans is popping out of gear there is wear being caused to other parts of the trans which can lead to other failures down the road. Probably better off to just find a used transmission rather than try to repair the one you have.

Replace the clutch when the trans is out. When the mainshaft bearing goes bad it stresses the clutch hub and eventually breaks it. If it hasn't broken already it is now fatigued and may break later.

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The front seal only leaks when the car is moving forward. The ring gear of the front diff slings oil up onto the back of the seal as it spins.

 

 

I'm going to see if I can find a picture I took with the motor out, I can't for the life of me figure out where it's coming from.. and it's rather thick too.. it's all on the front crossmember i figure that much it would be all on the clutch but it's never on the clutch or flywheel..

 

The fact that it happened on a transmission that only had 82K on it

 

DSC_2588.jpg

DSC_2582.jpg

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Great write up! I'm thinking it's time to replace my input shaft bearings- lots of noise, and now it's hopping out of 4th and 5th gear. Any advice on where to get the bearings and seals? (I'm guessing Subaru dealer?) Thanks!

 

If it's hoping out of 4th and 5th you need to replace the large bearing at the rear of the upper shaft too.  That's the one that locaates the shaft fore/aft in the trans.....when it moves, the shift collars jump and it pops outta gear.

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I'm going to see if I can find a picture I took with the motor out, I can't for the life of me figure out where it's coming from.. and it's rather thick too.. it's all on the front crossmember i figure that much it would be all on the clutch but it's never on the clutch or flywheel..

 

The fact that it happened on a transmission that only had 82K on it

 

DSC_2588.jpg

DSC_2582.jpg

 

Well, I know this much about the seal leaking: It shouldn't leak out around the input shaft. There is a weep hole at the base of the T-O bearing shaft that will leak the oil onto the housing behind the the T-O bearing.

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I'm going to see if I can find a picture I took with the motor out, I can't for the life of me figure out where it's coming from.. and it's rather thick too.. it's all on the front crossmember i figure that much it would be all on the clutch but it's never on the clutch or flywheel..

 

The fact that it happened on a transmission that only had 82K on it

 

DSC_2588.jpg

DSC_2582.jpg

This is valve cover gaskets, cam plug seals, or separator plate, or the rear wrist pin access cover o-ring, or a combination of any or all of those.

 

When the input seal on the trans leaks it runs down from the bottom of the snout on the transmission. Sometimes they run out the front and get all over the clutch.

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Those were just old leaks.

 

When the front seal leaks it runs down the inside of the bellhousing, runs back and leaks directly onto the center of the y -pipe from the trans drain plug.

 

The crud on the cross member is YEARS of small drips and oil running back off the engine and being blown onto the cross-member by wind under the car while its driving. A little drip, a little dirt sticks to it, some more drips, more dirt, and so on. After a while you have a layer of caked on dirt and several year old oil. Break out the purple power and a scrub brush and clean all that off if it bothers you.

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Trust me man i wiped it down about a year ago later when I pulled the engine again it was in the same spot.. it's no so much the crossmember I care about it's how it's all in the transmission bellhousing that concerns me.

 

I was going to open the transmission up (current one in the car) but one of the bolts snapped that holds the center diff to the transmission.. in that case because I had to move the car I decided not to mess with it further..

 

I did however buy all brand new seals for the transmission, only seal I ended up using was the one for the driveshaft, next transmission I will be getting I'm going to put a front LSD in so in that case I will be doing all the seals.

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The front seal only leaks when the car is moving forward. The ring gear of the front diff slings oil up onto the back of the seal as it spins.

 

Sly, if the trans is popping out of gear there is wear being caused to other parts of the trans which can lead to other failures down the road. Probably better off to just find a used transmission rather than try to repair the one you have.

Replace the clutch when the trans is out. When the mainshaft bearing goes bad it stresses the clutch hub and eventually breaks it. If it hasn't broken already it is now fatigued and may break later."

 

Thanks. I'm really interested in learning to work on transmissions, and I learn best by getting things apart and looking around inside. I just have no idea where to get the bearings that I know I'll need (or other worn parts that I might find in the process.)

Edited by sly1976
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The mainshaft ball bearing has to be pressed off and the new one pressed on. It can be removed with a very large puller and the new bearing hammered on using the inner race of the old bearing, but its much easier with a press.

The lock nut on the end of the shaft is torqued to about 90ft lbs.

loosen and remove the lock nut, pull the 5th gear synchro set being careful not to lose the lock tabs, pull the 5th drive gear and the needle bearing off the shaft. The 5th needle bearing inner race will be pulled off with the ball bearing.

Once the ball bearing is off pry the ball retainers out and roll the balls all to the bottom. Tap the bearing on the ground or bench and the inner race should pop loose. If not slide it over a pipe or prybar in a vice and knock the top of the outer race with a hammer once or twice. Clean up the inner race and use it as the "special tool" to install the new bearing and the 5th gear needle bearing inner race.

 

Be sure to pay attention to the snap-ring on the outer race of the ball bearing. If you install the new bearing with the snap-ring on the wrong side the bearing will not fit in the case.

Put some grease on the mainshaft and press or hammer the new bearing on, then slide the 5th needle bearing race on and hammer or press that on. Be sure the race, needle bearing, and gear all go back on the same way they came off.

Once that's all on install the 5th synchro and hub and tighten the locknut to 90ftlbs.

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The mainshaft ball bearing has to be pressed off and the new one pressed on. It can be removed with a very large puller and the new bearing hammered on using the inner race of the old bearing, but its much easier with a press.

The lock nut on the end of the shaft is torqued to about 90ft lbs.

loosen and remove the lock nut, pull the 5th gear synchro set being careful not to lose the lock tabs, pull the 5th drive gear and the needle bearing off the shaft. The 5th needle bearing inner race will be pulled off with the ball bearing.

Once the ball bearing is off pry the ball retainers out and roll the balls all to the bottom. Tap the bearing on the ground or bench and the inner race should pop loose. If not slide it over a pipe or prybar in a vice and knock the top of the outer race with a hammer once or twice. Clean up the inner race and use it as the "special tool" to install the new bearing and the 5th gear needle bearing inner race.

 

Be sure to pay attention to the snap-ring on the outer race of the ball bearing. If you install the new bearing with the snap-ring on the wrong side the bearing will not fit in the case.

Put some grease on the mainshaft and press or hammer the new bearing on, then slide the 5th needle bearing race on and hammer or press that on. Be sure the race, needle bearing, and gear all go back on the same way they came off.

Once that's all on install the 5th synchro and hub and tighten the locknut to 90ftlbs.

Thanks so much for the great info! Just got the parts and have the transmission out. I'll be splitting the case and trying it tonight!

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  • 2 weeks later...

Many thanks to Gloyale for the instructions.  I used them to tear apart my trans yesterday.  Would be glad to take and post another picture or two if it would help others.  I'm being charged $70.48 for the ball bearing, $42.22 for the needle bearing, $14.45 for the seal, and "about $7" for the gasket that goes between the rear section of the case and the two front halves of the case.

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  • 8 months later...
  • 10 months later...

Found this site today. I was looking for just this kind of information. My 2002 Outback has this front seal leak. Wasn't sure I would find any info on the subject. Now I'm thinking of doing the work myself. 

 

Thanks!

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Sorry I never updated earlier. Thanks to all the great info here I was able to pull it all apart and rebuild it. The input shaft bearings were shot, but everything else actually looked pristine. I replaced the bearings and seal, and many miles later it's still working great. The wosts part of it was hammering on the shifter shaft to get it back through the case. Definately a job worth doing if you enjoy knowing your Suby better though. Thanks everyone!

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  • 3 months later...

Found the "pearl of wisdom" EJ25 manual gearbox seal replacement from years-ago.  When doing EJ25 engine replacement, gearbox had about 1 mm play on input shaft. Anyone who has seen a manual gearbox or replaced that input shaft bearing, how normal is 1 mm play? I have no reference point. Curious if I have a gearbox bearing change-out in my future and how soon? Advice?

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