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Discussion Starter · #1 ·
Hey all. Im on my second Subaru, this one is a 2008 Outback 2.5i 5spd mt with almost 120k on the odo. I had to sell my 32k mile Legacy mt because of a transmission problem and now I'm getting some serious deja vu with the Outback. The problem is it makes a ticking noise only under load and above 25-30 mph. Its doesnt make the noise when coasting but soon as I apply a bit of throttle the noise comes back and it is proportional to engine load. I swapped out the front left CV axle last night to eliminate that and this morning I lifted the car on all 4 points and get under it while I had someone run the car in 5th gear to get the wheels to spin (noise is most obvious in 5th gear) and I discovered something interesting. All 4 wheels spin except for the front left (dont blame it on the CV axle, I've done that job on 3rd gen Subaru at least 5-6 times). My immediate thought was wheel bearing but there is no noise while driving or turning to indicate that. Under the car I determined that the ticking noise was definitely coming from inside the trans. I really like these cars but so far they're just beating me to death, I'm just a broke college kid after all. Thanks for the help guys!
 

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2008 OB Limited 2.5i, Portland OR USA
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Clarification - when you swapped the front left CV axle, did the noise under load go away? Or is the MT noise you heard underneath something different?
 

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Discussion Starter · #3 ·
Unfortunately the noise did not go away, in fact nothing changed at all. I did check for a bad bearing when I had the cv axle out but I don't recall the FD wheel being hard to turn so I really don't think its bearing drag or anything else that's causing the wheel to not spin when its in the air like that. Could it be a viscous coupling maybe?
 

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06 3.0R JDM facelift SI Drive-shift paddles. 87 Brumby EA81 (Brat) 4MT D/R
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It could be the right axle ( inner CV perhaps) noises sometimes have the ability to travel / fool you.
Silly question (guess you will have done this already ) but have a look at transmission oil level on its dip stick and its condition (colour on stick) too see if that shows anything out of the ordinary with trans.
 

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Discussion Starter · #5 ·
It could be the right axle ( inner CV perhaps) noises sometimes have the ability to travel / fool you.
Silly question (guess you will have done this already ) but have a look at transmission oil level on its dip stick and its condition (colour on stick) too see if that shows anything out of the ordinary with trans.
The trans oil level is right at F and is surprisingly clean, doesn't smell burnt at all. In fact I'd say it's been changed in the not too distance past. The only reason I suspected my left CV axle was because I read about a similar issue on the forum and that was a suggestion and I happened to have a CV axle lying around from my last Subaru. So far none of my mechanical intuition has even hinted at the CV axle being a problem.
 

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Discussion Starter · #6 ·
I did some more fooling around with the car while it's up on the jack stands and I found that after running it in gear the front left wheel will actually spin backwards when I shut the car off.
 

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Has the transmission oil ever been verifiably changed?

You have an extra axle - swap it with the other side, left and right are the same part.

Load dependent noise is often the inner CV joint or the front diff. Hit throttle for any reason, like going up a grade, and noise starts happening or increases.

It's an open diff, it's no surprise if one tire spins and the other doesn't. That's what open differentials allow by design.
 

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Discussion Starter · #8 ·
Has the transmission oil ever been verifiably changed?

You have an extra axle - swap it with the other side, left and right are the same part.

Load dependent noise is often the inner CV joint or the front diff. Hit throttle for any reason, like going up a grade, and noise starts happening or increases.

It's an open diff, it's no surprise if one tire spins and the other doesn't. That's what open differentials allow by design.
I understand it's an open diff but both wheel should spin unless there is more resistance on one side. I tried to spin the left wheel to get it to start and it just didn't want to. I had the CV axle out and saw that there wasn't any abnormal resistance in the wheel and I know that the CV axle is good which means that there is no way the left side can have more resistance than the right side. Does that indicate a bad diff bearing maybe?
 

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I understand it's an open diff but both wheel should spin unless there is more resistance on one side. I tried to spin the left wheel to get it to start and it just didn't want to.
That too is normal. As long as the torque required to turn the supposed more free wheel is less than that needed to turn the less free wheel, the torque will be limited to the lower level and the less free wheel will not turn. When the less free wheel was manually turned that didn't change the torque needed to turn it. When it was released, its required torque was still higher than the other wheel, and so it didn't turn on its own.

A suggestion, if you're willing:

With the car up, parking brake applied to keep both rear wheels from turning, transmission in a gear, and engine off, when one front wheel is turned does the other turn the same amount but in the opposite direction? Try with both front wheels, and turning forward and backward. Check for clicking, periodic resistance, and any difference when turning the right or left wheel. Note the amount of force needed to turn each wheel, which might be close if not the same. Then . . .

With the same setup as before except the transmission in neutral, rotate one front wheel while someone (or something) prevents the opposite wheel from turning. Get a sense of the ease, or resistance to turn that wheel (both directions), and again, check for any noises or varying resistance. Compare to the ease or lack thereof when turning the wheel in the first test. Then do the same at the other front wheel. Be interested in whether or not there's a noticeable difference, and if there is a difference, which wheel is the more difficult to turn.
 

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Discussion Starter · #10 ·
That too is normal. As long as the torque required to turn the supposed more free wheel is less than that needed to turn the less free wheel, the torque will be limited to the lower level and the less free wheel will not turn. When the less free wheel was manually turned that didn't change the torque needed to turn it. When it was released, its required torque was still higher than the other wheel, and so it didn't turn on its own.

A suggestion, if you're willing:

With the car up, parking brake applied to keep both rear wheels from turning, transmission in a gear, and engine off, when one front wheel is turned does the other turn the same amount but in the opposite direction? Try with both front wheels, and turning forward and backward. Check for clicking, periodic resistance, and any difference when turning the right or left wheel. Note the amount of force needed to turn each wheel, which might be close if not the same. Then . . .

With the same setup as before except the transmission in neutral, rotate one front wheel while someone (or something) prevents the opposite wheel from turning. Get a sense of the ease, or resistance to turn that wheel (both directions), and again, check for any noises or varying resistance. Compare to the ease or lack thereof when turning the wheel in the first test. Then do the same at the other front wheel. Be interested in whether or not there's a noticeable difference, and if there is a difference, which wheel is the more difficult to turn.
You have to consider the differentials internal resistance as well, a minute difference in friction won't cause one wheel to completely not spin. You have the torque of the engine pushing through the diff and against whatever difference of friction either wheel has. If one wheel doesn't move THATS NOT NORMAL. I did already state that with the CV axle out I didn't notice any unusual drag while spinning the left wheel. Spinning either front wheel with the rears locked doesn't really tell you anything because the two wheels are connected mechanically so any perceived resistance could be coming from either side. At this point I'm fairly convinced its an internal transmission problem, likely the front diff.
 

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(formerly) 03 H6 OBW , (presently) 06 WRX Sportwagon & 2021 Honda CR-V
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there's ALWAYS more resistance on one side - it only takes a minute difference .


when you shut the car off, the moving wheel had momentum and that was instantly transfered to the other side. Same as if you manually turn one wheel and observe the other.

not saying you don't have a trans problem - my WRX's 5spd had to be rebuilt when it chewed-up 2nd gear. less than 70K miles, NO power mods!

look on the drain plug for 'chunks' and consider sending a lube sample to Blackstone labs.
 

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Discussion Starter · #12 ·
Finally got around to looking at the Subaru again. I drained the trans oil and it was actually surprisingly clean. Had a light brown color. Absolutely no particles or metal chunks in it.
 

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2005 OBXT Limited, VF37, STI intake, 5MT
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Did the ticking noise come from the center to center-rear section of the transmission?

If so, the center differentials can throw the large snap-ring that keeps the viscous fluid together. Under stress or large amounts of heat (driving on mismatched tires, clutch dumps, trying to drive like Ken Block), the snap rings can partially spring-out and contact the interior or the trans case.

With all 4 off the ground, rotate the driveshaft by hand and listen for a cyclical click. If so, you may have to pull the tail housing and inspect. This can be done in the car.

While you're under there, however, CAREFULLY inspect the driveshaft u-joints for play. Grab both ends of the yoke and counter rotate. If ANY play/slack is felt, it needs replaced.
 
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