Subaru Manual Transmission Repair

Subaru manual transmissions are pretty well built and have minimal problems. When failure occurs there are usually just a couple of things that fail. The most common problem is bearing failure causing the transmission to be noisy and if it’s excessive your trans will sound as if someone has put rocks in it. The other failure that is common is the viscous coupler. In Subaru MT transmissions the viscous coupler acts like a limited slip differential, but instead of allowing slip from the left and right tires the viscous coupler allows slippage of the front to rear wheels. This is for turning only because the front and rear tires while turn at a different rate in turns. The viscous coupler will also slip if the vehicle is under a heavy load going straight and when this occurs the power will be mainly transferred to the front wheels. Most of the time viscous coupler failure is on a WRX model, where the snap ring breaks out of the viscous coupler case. When this occurs there is no power transferred to the rear wheels.

These transmissions are pretty simple to repair, so if you would like to perform your own repair I will give you some tips to help you along the repair procedure. If after reading this you decide that the equipment needed and/or this seems like a little too much…

MDH Motors Specializes in Subaru MT Transmission Repair

Contact us today for an estimate!

Do it yourself Subaru MT Transmission Repair

Do it yourself required tools

  • Shop press
  • Split bearing puller (large and medium size)
  • Press fittings Tip: use different size exhaust pipe and old bearing races.
  • 55mm 6 point socket (mid or deep)
  • 44mm 6 point thin walled socket ( shallow OR deep)
  • Air Tools (1/2” Impact Gun)

First off, separate the transfer case unit from the main transmission case. After that is done, the biggest part that makes this easy is how you split the case and dis-assemble the transmission. The left side of the case will hold you input shaft, counter shaft, differential and shift forks and the other side is just part of the case. Just remove two of the four bolts holding the counter shaft main bearing from the side of the case your removing (at rear of case where transfer case unit was). Always mark the shim that is behind this bearing. It may not seem necessary, but upon re-assemble you can easily mix up how this goes and the holes won’t align correctly.

Now that this is done the rest is pretty self-explanatory, remove your shafts and press on and off the bearings that need replaced. I always recommend replacing all ball bearings and seals. There are some small flat bearings and round bushing type bearings that are OK to re-use. Use your split bearing puller and array of exhaust tubing to remove and press new bearings to the shafts. I use an assortment of 1’ to 3 ½’ exhaust tubing in ½’ increments for the job and also have some roll cage tubing that is more heavy duty for pressing some stubborn bearings. Another good tip for substituting your press fittings is to keep the bearing races. They can become very handy for certain needs, especially if you have a welder. You can then weld and fabricate special press fittings exclusively for certain jobs such as this.

When you get to the differential, do not move or adjust the carrier bearing adjusters. Replace the seals from the inside of the case, and if you want to replace the large O-rings in the differential carrier bearing preload adjusters just mark them. The service manual will tell you to use special tools such as dial indicator to adjust backlash. I have been working on these transmissions for over 10 years and have never had a problem doing it this way when replacing the differential carrier bearings. Another thing to look for that I see sometimes is these bearing races sometime have a tendency to spin in the case. Especially if the bearing is worn, causing drag. To resolve this problem just take a pointed punch (I use a spring loaded one) and ping around the case where the race fits. This will cause the race to fit tight again, cool huh. No need to replace the transmission case.

Hope this was helpful

This post was written by: Martin Hand

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Martin Hand

About Martin Hand

ASE Certified L1 Advanced Mastertech. Martin Hand has over 15 years experience in Asian and European Import Auto Repair. Specializing in electrical diagnosis, engine performance, AT/MT transmission repair/rebuild. Martin is also pursuing a degree in Computers Science & Information Systems starting at Portland Community College while he plans to transfer to OIT. Certified in Java application level programming, experienced with other languages such as PHP, Ruby, JavaScript and Swift. Martin has future plans of automotive diagnostic software development.

153 Comments

  • Lincoln says:

    Hi 03 Subaru 5speed ty754 put new clutch in went from duel mass to normal I have a noise like grinding plus I have no drive was thinking I might need it full of oil as I emptyed it but thought this would not make a deference

  • dimitri says:

    hello! after replacing my clutch cable (my brother nearly snapped clutch fork on my 200 NA frankestein built subie with stage 2 clutch) i was able to drive again but noticed i couldnt get into 5th gear at all (the gear that he claims the clutch went into the floor at. one morning i got in to move the car a few days after the repair and only about 10 miles since clutch cable replacement and i put the car in reverse without letting warm up (i live in florida it wasnt cold out ) and it went in very smooth and then bam i try to go back into first and its literally stuck in reverse….. im at a lost for words. is this the shift forks? no matter how hard i pushed the shifter it will stay stuck in reverse but i noticed the shifter looks like it is in neutral but still stuck in reverse . i was only able to move car back into driveway by having my friends push me with the clutch pressed in as it will roll like that.. do i need a new transmision?

    • Martin Hand Martin Hand says:

      You can disconnect the external shift linkage and try to shift it through the gears. If it’s still stuck then you’ll have to remove and take apart the transmission to see what’s wrong.

  • Shawn Clayborne says:

    99 legacy 5sp manual , pops in every gear when under load or acceleration and can feel it like something is slipping , thank I for any help

    • Martin Hand Martin Hand says:

      Something’s either wrong with the shifter linkage, shift forks or gear synchronizers. So it could be an external or internal problem.I wouldn’t know for sure unless I seen the vehicle for myself. Most likely will need to remove the transmission, tear down and inspect.

      • Dan says:

        I have a 99 legacy awd and first and reverse grinds and resists going into those gears. Can you explain the sychronizers and related components operation and purpose. I’m interested in learning about the design, purpose and operation of the sychronizers and if you could pass some knowledge to me so I can diagnose that I do in fact, have to remove trans to inspect internally or if maybe its linkage possibly. Only problems with those two gears trying to get into them-grinding, then eventually goes into gear and I can finally pull off from a stop; the above problem/symtom is intermittent. you can be brief, I worked in a shop and farmed out trans jobs but this one is on me! Internals are unfamiliar. Thank you so much!

  • Walter Vichas says:

    Hello I have a 2011 Subaru Outback with a 6-speed manual transmission clutch pedal went all the way to the floor I thought it was a clutch slave master cylinder but it was not I replace the clutch now I don’t have 4th 5th 6th or reverse gear it was making a grinding sound when I push the clutch in and then it went away then the pedal went all way to the floor I drove it for about 25 miles home and I lost those gears please advise

  • Sam says:

    Hey, i have a problem here with a 2004 WRX 5-Speed.
    Ever since i accidentally grinded 1st gear, it has been hard shifting into and out of 1st gear.
    What would be my best bet?

  • Andy says:

    I have a 2004 Outback manual (190,000km) and had the gearbox rebuilt with all bearings replaced 12 months ago, but not the centre diff bearings and pretty sure not the viscous coupler.
    For five or six years I’ve towed a pretty heavy caged trailer camping over the Christmas Holidays.
    I now have a very similar noise to the previous transmission problems coming from the same area?
    Do you think is sounds like the centre diff & viscous coupler?
    If I was to replace the centre diff bearings is it common practise to do the viscous coupler at the same time?

    Thanks.

    • Martin Hand Martin Hand says:

      You should have all the transfer case bearings replaced with the rebuild. They are usually noisy on the rebuilds I see. I don’t replace the viscous coupler unless it is having binding issues or the snap ring pops out. Usually just replace bearings.

  • Michael says:

    Thank You for specializing in the Subaru. I have a couple of “easy” questions concerning the 5 speed 4.44 ratio transmission. I have 2 of them, Ty755vh4aa Ty755vw5aa. The questions are: one has stub shafts coming out of the front differential the other one does not. Are the stub shafts removable, can I switch from one to the other? I am installing one of them in a SVX and my 1/2 shafts are made to slide on a stub shaft. Do I need to change out my 1/2 shaft ends? what would work?
    One of the transmissions look like it has a cable drive for the speedo? The other looks like a electronic speed sensor. Is there a way to change out the “cable drive” or is there a unit that I can install that will adapt the cable to electronic?
    Thank you

    • Martin Hand Martin Hand says:

      The differential needs changed or you can try fabrication of the cv axles. I don’t know about the speed sensor, you can try fitting a sensor or cable drive to the transmission.

  • teri felkel says:

    I’m working on a customers 2012 outback. replacing the center diff due to binding on turns. I noriced that the upper extention case baerring race ( shaft for driveline) is spinning in its seat. is this normal? it does not look as though the case is damaged in any way. and this trans was not making any noise that I know of. the race comes in and out very easily and has a thrust washer behind it.

    • Martin Hand Martin Hand says:

      That’s normal the race doesn’t spin when everything’s put back together and the bearing is preloaded. Don’t forget to put back the shim and if should be fine.

  • Cory says:

    Hello I have a 2012 Subaru Forester. Used heavily for work related travels. Currently 169,300 miles on the odometer. The engine short block was replaced due to oil consumption recall at 160,000 miles and at that time they also replaced the clutch and flywheel too.
    Now with nearly 170,000 miles on my 5 speed transmission the 3rd and 4th gear are often grinding when going into gear.
    My mechanic test drove it around the block and equated the grinding to 3rd and 4th gear synchro failure. His recommendation was a rebuild of replace.
    Is that mileage commone for a Subaru transmission to wear out?

    • Martin Hand Martin Hand says:

      It not that common to have synchro failure, usually just bearing failure. It could be a bent or worn shift fork and/or the gear align teeth also. You’ll have to take it apart to find out. Our rebuilds are usually $1600 to $1800 without significant hard part damage.

  • John Coffea says:

    Martin, In 8/2012I bought a pre-owned certified, 2011 Impreza (2.5, non turbo)carrying an updated 7yr 100,00 mi warranty. At 29,000 in Aug 2013, car was in accident where I t-boned somebody that blew a light as they cut across in front of me. When the cars came together, my hand was in process of shifting to 3rd and I felt something pop thru the shifter as my body weight shifted forward, and the stick’s travel bottomed out. Have you ever heard of anyone bending shifting forks in 5mt? I mentioned this to body shop manager(it was a Chevy dealer) and as part of repair, citing lack of experience with my transmission, they shipped it down street to Subaru dealer to be checked. Dealer changed the oil, saying to me that there was some metal shavings in it. (Will get back to this later) finished, they retuned car to body shop, I picked up what I thought was a fully repaired car. One mo later it started grinding going into 3rd, also popping out of 3rd by itself, with me having to hold it in to keep it in gear. I returned it to Subaru, they serviced it again, things were ok for bout 3 mo, then grind switched to 4th, still popping out of 3rd. Grind was not major, only a minor inconvenience, tired of all the downtime, and as my commute was 95% hi-way, I ran the car 40mi total per day. At 80,00, the unit lost the ability to shift into 3rd or 4th. only 1,2nd and 5th were working properly. I week later total failure, trans locked in a gear( don’t know which) in neutral position. Only way car moved was to disengage clutch. Towed car to Subaru, this time they took it apart(previously they didn’t), and Subaru of America immediately notified me of their intent to refuse to honor warranty, citing abuse, and lack of maint,,, by me. ???? Getting back to initial metal shavings in oil in 2013, do you think they were negligent in not splitting the case’s to find out cause of metal shaving’s and could a bent 3rd/4th shifting fork eventually cause this failure thru contact with rotating 3/4th gears? Someone told me the popping out of gear and 3-4th problems should have been a dead give away to them. Please advise of your thoughts, anything will help, if you need more info feel free to ask. They are saying new trans is$4000, with install of $2000,,, on a car worth at most $8,500? I think they waited too long and this should have been fixed in 2013,,(by the way I am 60 yrs old and LONG past my racing/abusing days),,Thanks in advance for any help,,John in De

    • Martin Hand Martin Hand says:

      The shift forks don’t usually bend but I have seen them wear down. It’s hard to say how this went wrong but the symptoms your describing are directly related to shift fork problems and can only be diagnosed by disassembly and visual inspection of the transmission.

  • Jordan Stanley says:

    Hi there. So I have a 98 legacy Outback with a bad bearing and hope to replace it with a 98 legacy GT. I’ve looked at the gear ratios and 5th gear is the only one that doesn’t match up but the final ratio is the same. My question is, would I still need to change the rear diff when the final ratio is the same. Thank you!

    • Jordan Stanley says:

      Hi, this is a follow up on my last post. To clarify: my 98 legacy Outback tranny is a TY752V2DCA and hope to replace it with a 98 legacy GT TY752V2DAA. The 5th gear ratio on one is .871 and on the other is .780 with the final ratio at 4.111 thank you again! And any help would be greatly appreciated!

    • Martin Hand Martin Hand says:

      If the final drive ratio is the same then it will be okay

  • Paul D says:

    Hi, I have recently had a TY754VN4AA gearbox fitted to my 2002 WRX as a replacement for the original TY754VN2AA that had developed centre diff bind and drop gear whine. The new box seems fine apart from some of the noises it’s making! There is a very pronounced whine on acceleration, reminiscent of a straight cut gearset, similar on deceleration too. With any throttle applied, even just to hold the same speed, the car makes a sort of quiet air rushing noise, only with any throttle applied though. Doesn’t matter what engine revs, also heard below boost threshold so I don’t think it’s a boost leak. Oh, also, when shifting into 5th there’s a noise that sounds a bit like the sound you get if you haven’t fully depressed the clutch. Any ideas? Thanks!

    • Martin Hand Martin Hand says:

      It could be the release bearing if it wasn’t replaced. I don’t know about the transmission you changed it with but if it’s for racing then probably has different cut on the heats and the noise could be normal. Really wouldn’t know unless I seen the car just too many variables.

      • Paul D says:

        Nah, just used for standard road use, no mods on engine etc. Completely understand it’s difficult to give an opinion without actually hearing it, but thank you anyway 🙂

  • brandon says:

    I have an 03 wrx that was manufactured in 02 and have the thin gears and I broke 5 teeth off 3rd gear, I was thinking of using legacy gt gear upgrade does anything need to be modified? also is there a book that tells torque specs for everthing and spacing? My uncle had rebuild transmissions before and said he could help me.

  • josh says:

    hi have a 2008 Subaru forester its making a bad winding noise when driving with clutch in or out it makes the same noise, what would be its 100% coming from the tranny how do I fix it

    • Martin Hand Martin Hand says:

      Sounds like transmission bearings failing. Transmission needs removed and overhauled. Usually will just needs bearings but need to remove, teardown and inspect to be sure no hard part damage.

  • Robert Leibold says:

    I have a1999 Subaru Forester with a failing 5-spd manual transmission and a 2001 Legacy with a failing everything else, but a good 5-spd manual transmission. Can I have the Legacy transmission put into the Forester for one reasonable car?

    • Martin Hand Martin Hand says:

      Yes but you need to match the rear differentials also. So either remove the rear differential cover and count the ring gear teeth or swap the transmission with the rear differential.

  • Pierre de la Rey says:

    Hi,

    Forestor came in for repair 250 000km on clock,
    Very little clutch as it smelled burnt.
    On test drive found whine in 3rd 4th and 5th gears.
    Advised transmission replacement and clutch at once.
    Replaced second hand gearbox on owners request and fitted new clutch and skimmed flywheel.
    When we test drove it we found that the rear wheels were locking up in tight parking or turns.
    Checked tyre pressures and size ..ok
    Not sure if it was doing this before as clutch was bad.
    Told supplier of second hand gearbox , they said the ratios were wrong . We checked and compared but the ratios were the same.
    Supplier provided a rear diff to suit. Assuming it came out a smashed vehicle.
    Fitted diff , problem still there.Also clutch is now burnt and shuddering.

    What a Nightmare!!!

    Is this the viscous coupling in the second hand gearbox supplied?
    Help!!!

    Regards
    Pierre
    Autocorrect

    • Martin Hand Martin Hand says:

      Double check your gear ratios and make sure the differential is free and not binding. I would recommend repairing the original transmission or at least swap the viscous couplers.

  • Brian Exner says:

    I’ve got a 98 Legacy L wagon 2.2L with a bad transmission. It pops out and/or grinds in every gear. Are you aware of a rebuild kit for this transmission? My local shop can’t find one. If not, I understand that any 5MT from a car with an EJ22 engine will work, as long as I match the final drive to the rear diff. Will differentials from different cars fit my Legacy, or is that a long shot? Can I just replace the gears in my differential housing? Or can I replace the final drive gears in my used transmission to match the car’s existing differential? Thanks for any help you can offer!

    • Martin Hand Martin Hand says:

      You can get the individual MT transmission parts from Subaru dealer. I would recommend to disassemble the original transmission for the vehicle to see what’s wrong. You can also get a used unit just make sure to match the differential gearing.

  • Lauren Sargent says:

    I purchased a 2002 Subaru Outback with 130 K. I love the car but…. When I let out the clutch in 1st or reverse, it sometimes shudders. Also, sometimes the engine stalls and it feels like I have hit a very solid object (like a tree. The car comes to a complete stop when this happens. In the complaints I have read online, I haven/ seen anyone else describe this problem. It happens mostly when the car has been driven far enough for it to be well warmed up. The clutch was replaced before I bought it and also the the AWD unit pn the rear of the transmission.

    • Martin Hand Martin Hand says:

      The shudder is most likely caused by a warped clutch pressure plate and/or warped flywheel. Maybe they didn’t machine the flywheel when they replaced the clutch.

  • Christian Guzman says:

    So I have a deep grinding noise coming from the tranny. The noise is weird because when I push the clutch in at all the noise goes away instantly. Same if I were to give it a little throttle. I mostly hear the noise when I decel in 3rd and 4th around 3000rpm. I fixed the center diff and transfer case bearings but it still makes the noise. What you guys think?

  • Greg Pearson says:

    In general, is the 5-speed MT from a Legacy the same as in Impreza/WRX? (Same year cars).

    Thanks!

    • Martin Hand Martin Hand says:

      Depends on the years. The MT 5 speed transmissions are probably the same but they have different final drive gearing that has to be matched with the rear differential on AWD models and most all Subaru’s are AWD.

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