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Old 02-18-2011, 04:45 PM   #1
Matt.Dieterich
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Default Bad Synchros or change M/T Fluid?

Hi all,

I am having trouble with my 07 impreza 2.5i I just bought a week ago. With the car off it is hard to change gears and sometimes is when I am driving. 3rd and 4th gear are hard to enter when parked and 2nd and 5th gear are also hard to enter when driving. Clutch is full depressed when I shift. I took it to the dealer where I bought it from and they took me to their garage and they test drove it with 2 technicians and said nothing was wrong with it. I know something isn't right with the way it is shifting because I am driving casually and shifting around 2,500rpm and letting out the clutch slowly while reapplying the gas as needed.

Are my synchros bad or would a M/T fluid change help? Which fluid is preferred? My car has 63k miles on it. I am also having a noise in my drive axle that the local subie dealer diagnosed. I thought the noise was coming from my left front tire, but the subie dealer said it was in my drive axle. Also the subie dealer said some bolts are different on the bell housing or tranny, they thought someone might have replaced the clutch or did something with the tranny. On carfax this car was used as a Corporate vehicle, so I have no clue who would have been driving it. I am trying to have a tranny shop look at my car if the dealer I bought it from will pay for it. I do have a 2 year GWC warranty on this car.

Should I change the tranny fluid or might it be something more serious such as bad synchros?

Thanks,

Matthew
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Old 02-18-2011, 07:17 PM   #2
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You should post this question in the transmission/driveline forum
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Old 02-18-2011, 07:40 PM   #3
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You should post this question in the transmission/driveline forum
This.

Also, change your fluid to Redline Lightweight Shockproof unless you live in a really cold climate. It's ambrosia for synchros.
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Old 02-18-2011, 07:43 PM   #4
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Well were there any records of service on the car?

Eitherway when I get a used car I change ALL the fluids on it. Better safe then sorry.
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Old 02-19-2011, 03:27 AM   #5
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Did you buy it from that dealership?

If so, they might just be pulling your chain a little. From the way it sounds, it's broken in some way, say a bent shift fork or something. When the car is parked, there should be no reason it can't go into any gear. It may not like reverse if it's not aligned, but that's normal for all cars. You should be able to whip through all the gears piece of cake though when the car is stopped. When driving you shouldn't have a problem shifting into gears either during normal use.

The drivetrain is still under warranty, so if you seriously think something is wrong, bring it back again and express your concern again. Have a tech ride with you (you driving) and explain it to them. If you're somehow driving wrong (for whatever reason) he'll point that out to you. If it happens regularly, the tech should then be able to drive the car and notice it too.

Dealerships don't like warranty work because they lose money. Sometimes the more shady places play games to get by with less if they can. A good dealership will just do the work and not complain about anything. As well, the car rental will be free to you if it is a warranty job. The powertrain is 60,000 miles, 5 year, so you're still good for that. That means whatever is wrong is free to you.

As far as gear oil, Shockproof wasn't specifically built for normal car use, but people tend to still use it. In terms of overall performance, Motul Gear 300 is the best stuff out there. The Shockproof simply has an additive package that helps resist shear in high power applications (like race cars), although it may or may not have adequate additives for long term use (like corrosion protection). People haven't complained yet about it, but no one's really compared the product in detail either. Royal Purple had problems years back because people started using their racing products in normal cars. They made great engine and transmission oils, very slippery, worked great, but it had no protection for long term use since it was designed for race vehicles. Royal Purple changed their formulas after a pile of complaints and bad-mouthing, but people do need to understand that products engineered for racing aren't always viable in a consumer application. Redline has been around for some time though and has been very widely used, but Shockproof is still a products geared towards the racing community.

Last edited by Back Road Runner; 02-19-2011 at 03:32 AM.
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Old 03-13-2011, 05:15 PM   #6
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I appreciate all the advice. After changing the tranny oil once with 80w90 Valvoline it is still hard to get into 5th gear when driving. I will try another fluid. I will try Motul Gear 300 and see if it helps. If not then I will have the subie dealer look at it again. They first told me nothing was wrong the other week.
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Old 03-13-2011, 06:54 PM   #7
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I have run the Motul personally and I can say it's ok fluid in the transmission. I prefer my newer choice of Amsoil severe gear however. 75W-90
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Old 03-14-2011, 05:22 PM   #8
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I appreciate all the advice. After changing the tranny oil once with 80w90 Valvoline it is still hard to get into 5th gear when driving. I will try another fluid. I will try Motul Gear 300 and see if it helps. If not then I will have the subie dealer look at it again. They first told me nothing was wrong the other week.
Redline Lightweight Shockproof is less expensive and will work wonderfully.
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Old 03-14-2011, 06:58 PM   #9
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I'm fine with the good ol extra-s.
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Old 03-14-2011, 07:21 PM   #10
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extra-s all the way!
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Old 03-14-2011, 07:24 PM   #11
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The extra s is the good for synchro performance, better than the amsoil.
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Old 03-14-2011, 09:13 PM   #12
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The problem is nothing may be wrong. It may simply be what you are physically doing. I simply don't know what you are doing. I don't know if you've driven a lot of manuals, driven more than that one Subaru, or how you physically shift the car. I don't know if you are actually having trouble getting the shifter into gear or are simply not matching rpms well, and it's just not falling in like you want it to.

You may want to go back to the dealer and ask to drive a different Subaru. Have a tech ride along and talk through the issue. Does it repeat with the other car? If you go into your car, can you repeat it with the tech riding passenger? Try to explain with him in detail what's going on and what's causing you trouble. You guys should be able decipher if the car is actually doing something wrong, or if it is simply expectations and shifting habits of your own that don't sync up with the car's behavior. You guys should be able to reach a conclusion.
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Old 03-14-2011, 11:11 PM   #13
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I used to drive a 2002 civic 5 speed that shifted so damn smoothly. I know subies have a lot more power, but I did go ahead and buy 4 quarts of Motul Gear 300. I currently have 80w90 Valvoline in the tranny so I am unsure if its a little too thick for the car. I try shifting smoothly by completely letting off the gas, clutching in and shifting into the next gear, releasing the clutch while reapplying the gas. Is there a better way I should be driving? I shift around 2500-3000k.

I just want to make it a smoother shifting car. I wonder if I am driving it wrong somehow.

Any thoughts Road Runner?
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Old 03-15-2011, 12:22 AM   #14
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The 80w-90 vs a 75w-90 would be just be thicker on startup (theoretically at least, there's a range of allowed viscosity for a certain number with regards to the 90).

Very simple question, but are you completely clutching in?
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Old 03-15-2011, 12:32 AM   #15
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Yes I am pushing the clutch down hard making sure I go all the way to the floor.
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Old 03-15-2011, 01:42 AM   #16
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The clutch is hydraulic. Much of what it does is near the top of the range, but the design is also relatively progressive through the upper half of the range. The bottom half of the range basically does nothing. For you to understand where things happen, stop the car, put it in 1st, rev a little bit, and slowly let out the clutch. Somewhere around half way up, you will start getting the clutch to grab and sending some power to the transmission. This is the first point that the clutch ever engages and does anything meaningful. As you let up more, the clutch will grab more and more and be able to transmit more and more power to the transmission. Very near the top, the clutch will be almost fully engaged. From near the top to top, it's still a significant jump in transmission of power and fully engaged engine.

If I have one suggestion for you it's: learn to rev match.

I keep saying this and people think I'm crazy, but the 5sp, at least the older ones, are sensitive to engine rpm despite the clutch being pressed.

Here's a simple test.

Find a back road somewhere with place you can coast slowly for a while. Speed up to 20mph, press in the clutch, let off the gas, and put the transmission into neutral. Let the rpms drop to idle. Lightly press the shifter towards 1st gear. It should feel like it's locked out of gear. You can press light to medium and it won't really ever drop in. You can shove hard, and it will typically go in. Some people have run into problems wearing out their 1st gear syncros doing so though, so I advise not to force things. Coast at 20mph and hold the shifter towards 1st for 10 seconds. Heck, hold it for 30 seconds. It won't matter. The car won't go into 1st gear. Now hold lightly towards 1st gear with the clutch pressed down and blip the throttle with your right foot. Get the motor to rev up to around 4k-5k rpm. Once you reach that rpm, you should find the shifter to drop into 1st gear with no effort. Repeat the process. 20mph, clutch down, idle, light pressure towards 1st. Now rev the throttle again. It'll drop right in. It'll do it every time and every time at the correct rpm for the speed you're going.

This is often why some gears, depending on your driving style, can be tough to get into. An example is speeding up down the on ramp. You go 1st, 2nd, 3rd, and most will shift right into 5th. Every time you go to 5th, you are stuck out of gear for an extra second. It feels weird. However, all that's happening is that you are waiting for the rpms to drop enough revs to let it fall into gear. You wait that little bit extra, and it falls right in. That's it. Some people end up shoving it hard into gear. I mean that's what the syncros are for anyways. However, people start to have issues wearing out their syncros too. Once a syncro is worn, it's worn, and all you start doing is grinding gears, and they'll grind every time, rev matching or not. I'd personally rather avoid that, so I always shift very lightly. Being smooth and quick is all about timing, not force.

If your car does this, it is sensitive to engine rpm. Yes, most manual cars, well pretty much all manual cars don't do this. However, I've driven a few different models of Subarus, and they all seem to act the same way. What this means for you is that if you want the shifter to drop right into gear, you start matching revs.

What I mean by rev matching is you match the rpm of the gear you're going into that is correct for the speed you're traveling. An example, let's assume 3rd gear at 45mph is 3k rpm. If we shift from 4th to 3rd gear, we will shift lightly from 4th over to 3rd and rev the throttle slightly up to 3k rpm to let the shifter drop into 3rd with nearly no resistance. If we are going from 2nd to 3rd gear, we will shift out of 2nd, move to 3rd, and then wait as long as needed for the engine to drop rpms enough to let the shifter fall into 3rd gear as we press lightly towards 3rd.

There is an added benefit of this. If we match rpms and only push lightly on the shifter, when it does fall into gear, it is at that moment synced with the engine and car's speed. The shift will be smooth, and you can let out the clutch quickly and get on the gas immediately right when it drops in.

There is a challenge though. Subarus in stock form are notoriously mushy. Part of this creates a lot of driveline slop that you can't really get rid of. There is also a lot of isolation so you feel nothing. You can't really feel the engine revs, the shifter dropping into a gear, or how much or little the clutch is biting. Even if you do manage to shift fine, you still have to apply throttle smoothly or the drivetrain will buck back and forth due to the mushy bushings. When it comes to shifting, Subarus are a giant pile of crap. If you can get good with a Subaru, like really good, you can hop into any other car on the planet and drive it like it was nothing.

If you want some fixes, you can look at upgrading bushings. This sort of depends on what you want to do with the car and how far you want to go with upgrading these parts. However, you can upgrade the shifter bushings to snug up the placement of the shifter, snug up the engine and tranny mounts to lock the engine and transmission into place and not have it twist and move around so much. This helps snug up the driveline as well as the shifter and provides a lot more feel of the engine and transmission through the car chassis. There can be added vibration related noise though. You can step to the back of the car and upgrade the rear diff outrigger bushings and rear diff rear bushings to finish locking the drivetrain to the car. This along with the engine and tranny mounts locks down the drivetrain and gets rid of nearly all the slop. Engine power feels very directly connected to the tires and road and the clutch engagement can be felt directly through the car. Stepping a little further you can even upgrade the suspension arm bushings and even the tophats to lock in the suspension to the chassis and keep the wheels from moving and twist. You gain much more precise handling as well as feel of power delivery and even braking. You gain feeling of tire grip and road surface, and grip/slip of the tires as well as sensation of the power being delivered to the ground. All of this is about snugging up the car, preventing a lot of the mush, delay, isolation, slop, etc., and providing a lot more feel and precision to the car. The more information the car tells you, the easier it is to drive. The more precise the car is, the more accurately you can drive the car. Bushings/mounts are game changers. A stock vs. fully upgraded car feels worlds different from each other, even with nothing else changed.
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Old 03-15-2011, 01:57 AM   #17
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Back Road Runner I really appreciate all the help.

I know the higher RPMs I am in 4th, the hard it is to get into 5th, so I try to get into 5th on the highway at like 40mph. I have been rev matching when downshifting and it helps for smoother shifting without all the jerkiness. Also I shift at 15mph from 1st to 2nd and it usually isn't smooth going into second, it's so different going from "drive by cable" in my civic to non-cable in my 07 subie. I wonder if this Motul Gear 300 will help clean the tranny out a bit.
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Old 03-15-2011, 08:28 PM   #18
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Well, the drive by wire system in Subarus is...delayed...and you will have to adjust to it. You will find yourself letting off the gas earlier and getting on it sooner than you would with a cable driven system. It is significant enough to force your to change your timing to become smooth again. With the soft stock bushings, it's hard to perceive the engine's rpms without actually looking down at the tach. It may just be that the engine isn't dropping in revs as quickly as you assume. Heck, getting off the throttle late will even blip the rpms up a little if you push the clutch in like you would with a cable driven throttle. You let off the throttle and clutch in, and the throttle by wire is still holding throttle for a tiny bit as you do so. The revs go up some, and you end up waiting longer to shift. In short, yes, you sort of have to relearn your timings to get things to operate more seamlessly.
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Old 03-15-2011, 09:53 PM   #19
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How will I know when its time to replace the clutch? Didn't know if that might help things, if the clutch is worn, and that would allow my subie dealer to see if anything else is wrong with the tranny...which the warranty would cover.
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Old 03-15-2011, 10:01 PM   #20
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Couple basics:

Bad syncro = grinding gears every time you shift into that gear. Clutch down, rev matching, double clutching, whatever, it will grind every time going in.

Bad clutch = will not hold power. You push down the gas, the engine revs up, but the car doesn't go. The clutch is slipping. Heavily glazing the clutch can end up with a similar result. It's an organic compound just like your brake pads and can be overheated and glazed just like your brake pads. Don't expect it to wear out under 150k miles.

Worn/damaged gears = constant whine while in that gear. Whine gets louder under higher load and changes pitch as you speed up or slow down. the gear surface is scuffed up and makes noise.

Bend/broken shift fork = trouble getting into specific gears or a complete inability to get into certain gears.


You are not describing any of these, so I'm leaning towards user error, well not error but maybe different expectations. You will really have to sit down with the tech and show him what's going on. Drive the car, make it happen, explain what you're feeling and doing. Then have him drive it with you as passenger and have him explain it and try to recreate it. Either something is wrong with the transmission or you are simply driving it in a way that is off. Either way, you and the tech should be able to work things out and come to a conclusion.

As for warranty, the clutch is a wear item. It isn't covered. It's just like your brake pads. It is a wear item, and it will wear. If you get it to wear in such a new car, you are likely doing something very wrong. You would have smelled burnt clutch often and would have to be slipping it a lot, riding the clutch, or doing something else stupid to actually get the thing to wear out rapidly. I have a 100k on my 02 Forester. I race it in auto-x and rally-x and as part of running the course, I launch the car at redline, slipping the clutch and have done an estimated 150+ launches. It's still the stock clutch on a 100k mile car, and it's still not worn. For you to actually wear out your clutch, you would have to be blatantly misusing the thing. You are also not describing anything associated with a worn clutch, i.e. slipping under throttle when you're in gear. A worn clutch is obvious and you will know it when it actually happens because you won't be able to give the car throttle without slipping, revving the motor without actually going forward, and smelling burnt clutch every time you do it. That is not happening to you, so no, it's not a worn clutch.

My guess right now is that you simply have expectations of the Subaru transmission, and it just feels off to you. The worst case, maybe you have a bent fork or something that is actually causing you trouble when attempting to get into gear.

Last edited by Back Road Runner; 03-15-2011 at 10:06 PM.
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Old 03-15-2011, 10:11 PM   #21
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Hi Back Road,

I really appreciate all the info...you know your stuff and it helps me out a lot. Why would you think that the higher my RPMs are in 4th gear the harder it is to go into 5th? I really have to force it in and I hate doing that to it...I would think it should be nice and smooth. My Motul Gear 300 oil will be here Thursday and I will put it in and see if it makes any difference in the smoothness of the gearbox. Even with the car off going the the gears its not fully smooth.
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Old 03-15-2011, 10:23 PM   #22
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What rpms are you trying to go into the gear? Is the engine even at the right rpm for the gear and speed? If not, it will not fall in easily, although you can shove it into gear if you really want to.

Subaru transmissions are notchy. They aren't butter smooth like other brands. They feel old and crude by comparison, very mechanical. The mushy bushings and drive by wire system really alienates you from what's actually going on, so it's hard to figure out what the car or you are doing wrong. A lot of things are hidden from you.

Don't expect the gear oil to be magical. Most of the gain from switching the gear oil to a synthetic like Motul Gear 300 or Amsoil Severe Gear is cold weather functionality. When it's 0F outside, stock petroleum based gear oil is crap until it warms up. You're pretty much forced to double clutch to get into gears, and you may be locked out of 2nd for a while, although I can't tell you why. Stepping to a synthetic lets it operate better colder and can be a big deal in colder climates were sub-freezing temps are common during the winter months. It also lets you drive the car cold without having it feel and operate sluggishly, and this helps gas mileage too in the winter time since you're not waiting so long and not shifting through jelly. However, once the transmission fluid warms up, there is no difference.

Syncro function can vary some depending on the slipperiness of the gear oil. A more viscous oil will let the syncros grab and function better. If the gear oil is too slippery, you may find yourself grinding gears even though the syncros aren't even worn. You may find a slight variation in how smoothly and quickly the car will go into gear when changing gear oils, but it's not exactly a game changer. The change isn't drastic.
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Old 03-15-2011, 10:27 PM   #23
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Quote:
Originally Posted by Matt.Dieterich
Hi Back Road,

I really appreciate all the info...you know your stuff and it helps me out a lot. Why would you think that the higher my RPMs are in 4th gear the harder it is to go into 5th? I really have to force it in and I hate doing that to it...I would think it should be nice and smooth. My Motul Gear 300 oil will be here Thursday and I will put it in and see if it makes any difference in the smoothness of the gearbox. Even with the car off going the the gears its not fully smooth.
5th is just like that. I suspect it is due to being an overdrive gear so the change is greater from 4-5 than any other gear change and the rpms have further to fall before the input output shaft speeds are close enough to allow the gears to mesh. And I also went through an adjustment period when I bought my 07 with the dbw system. Its a shame that the dbw is so unrefined but it can be tuned to get much improvement in the response and linearity if you have the time and resources.

Don't get your hopes up for that motul fluid to fix the issue... I've tried it, amsoil, redline shockproof and the factory subaru fluid called extra-s. The extra-s seems to be best for synchro performance in my experience but it took a few mins to warm up on cold mornings even here in Florida. Cold being 25-35F.

BRR - Doesn't a double clutch shift eliminate the need for syncros since the driver sets the speed of the input shaft with the throttle and matches it to the output shaft?
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Old 03-15-2011, 10:51 PM   #24
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Hi guys thanks for the replies. How do I go about upgrading the parts you mentioned here. "Its a shame that the dbw is so unrefined but it can be tuned to get much improvement in the response and linearity if you have the time and resources."

Should I return the Motul Gear when it comes and just go to the dealer and have them throw in Subie tranny oil, or should I try to see how the Motul runs?

Matthew
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Old 03-16-2011, 12:35 AM   #25
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Double clutching syncs the shaft to the engine speed, even if that's wrong for the speed the car's traveling. It'll let you get into gear just fine, but it won't make the shift smooth once you let out the clutch. I only use double clutching when necessary, i.e. in the dead of winter before the transmission fluid is warmed up and the transmission isn't exactly being a team player just yet. Even with a good synthetic, cold oil is still thick, and the transmission doesn't operate so well.

Because the Subaru transmission still seems to react to engine speed even when the clutch is pressed, I opt to simply rev match and use very light force when shifting gears. When it falls in, it's synced with both the engine and car's traveling speed. Get the throttle and clutch timing good, and you'll shift smooth every time. Don't kid yourself though. It still takes years to get really good. I grew up driving a variety of manual transmissions. I've even test driven a large majority of the sub $20k cars out there. Not much out there acts like a Subaru transmission and not much out there is harder to get right. If you can get good at driving a Subaru transmission smoothly, you'll drive any manual transmission with ease. The same techniques you learn will apply to any other car you drive, and the cars geared to be easy to shift will be mindlessly easy for you. I don't hop in a strange car and wonder if I can shift it smooth. I hope in a strange car and know it can't be worse than my Subaru.

One thing I've enjoyed about the Subaru transmission is that it helps you get rid of bad habits. To use it really well you have to get really good. Then again, I've come to like building up an engaging, active driver's car. I drive a Forester, but it's 30% stiffer than an STI and the majority of the bushings and mounts have been upgraded. I run sticky summer tires and grippy winter tires, and I race it in auto-x and rally-x. It's a very active machine, always having your attention due to the increase in feel and precision. It's neat that you can build a product that hones your skills, a tool to better yourself. The transmission is simply one part that's there for you to do the work correctly and doesn't do anything for you. For example, some manual transmission cars run a valve that limits how fast the clutch engages. Even if you pop your foot off the clutch, it will still engage smoothly. The Subaru doesn't have this. If you mess up, it locks hard and jerks the car. The syncros are there so you don't grind gears, but they aren't there to make shifting easy no matter what you're doing. The transmission rewards rev matching and good timing. It makes you better because it is not forgiving. The soft bushings in the driveline make it very hard to drive slow smoothly. It has a rubber band effect that tends to buck the car mildly, or if you mess up violently. It forces you to engage the clutch smoothly and apply or let off the accelerator smoothly or slip the clutch lightly at appropriate times. It teaches. I'm still a fan of upgraded bushings and mounts though, because I like precision and feel. The more information the car transmits to you, the faster you learn and the more you know. Plus you can operate the car with higher precision and actually have that precision meaningful...like turning the steering wheel 1 degree actually means something and results in an immediate reaction from the car, unlike stock where it does nothing because there's so much play in the bushings.
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