Legacy GT - Noisy Manual Transmission

[jlefavour]

I'm a new Legacy GT owner, having recently purchased a 2008 with a 5 speed manual transmission. I've wanted one for some time, and so far, am generally happy with the purchase. I am however, bothered by what appears to be an abnormally noisy manual transmission. The two issues I have experienced are;

 

1) Gear lash type noise during deceleration in low gears.

 

2) Noise from transmission at idle when out of gear. - Sounds like the main shaft spinning, but I'd not expect to hear this on a car with so few miles.

 

I do understand that some level of both of these conditions is normal in any car, but this relatively new car is noisier in these respects than the accord I just sold with 301,000 miles. Can anyone shed light on this? I enjoy most of the sounds this cars drive train produces, but these two concern me. Just wondering if a trip to the dealer is in order, or if this is normal in subarus.

[rao]

Welcome!

 

Your description isn't very descriptive s o it is hard to tell what you are experiencing.

 

I can tell you that is helpful to think of the Legacy as a Farm tractor that goes reasonably fast and handles reasonably well and has an amazing interior (for a tractor).

[vr4Legacy]

I think our transmissions are a little noiser than most 2WD cars... but having said that, if you just bought the car, I would take it back to the dealer ASAP and at least let them hear and document the noise, that way if something comes up in a short time period you MAY be able to have them fix it.... or maybe you can get a warranty out of it if they don't want to do anything yet...

 

Powertrain should be 5 year 60k IIRC

[Max Capacity]

Mine has backlash noise too, but I'm way out of warrenty. When I had the bearings replaced last july I had them, independent shop, check the backlash. They were fine with it, the way it was. It's a trusted shop so I'm not worried too much about it.

 

The straight cut gears are known to be noisey too.

 

 

To help mine, I coast as much as I can. My GF has learned that too when she drives it.

 

Oh yea, You can't compare a Honda tranny to these .... let's see how can be, not to mean here...

[LegGT24]

Could be the flywheel or pressure plate making noise or you may need to replace the throw out bearing if it is going bad.

[wpmarky]

#1- gear lash noise is normal. As Max said, our gears are straight cut, which makes them a bit noisier.

 

#2- doesn't sound normal, take it back to where you bought it and have them look at it.

[Max Capacity]

Is there a loud whine under boost ?

 

Mine sounds like those old 1940's trucks running thru 1st and 2nd gear. That's pretty much normal.

 

When the bearings were going, the whine got very loud. You could tell the difference under boost and none boost conditions.

 

This was the second time mine had made the same loud whining. The first time for bearings was covered, that was Sept 08 at 95,200. Dealer rebuilt tranny.

 

After that mine lasted until July 27 10, 129,230 miles before they went again. Fluid was changed out at 124,200 miles Apr 14 10. I used redline at that change. It now has extra S in it again.

[lwood]

I first noticed my '06 doing that exact thing after I had the Xact clutch and lightweight flywheel installed. A trusted performance Subaru shop near Ashville, NC did the install for me.

 

I complained about the noise while decelerating (especially 1st and 2nd) and I complained about the noise during idle (This noise is not as noticeable, and it goes away when you hold in the clutch).

 

The shop guys said the throw out and everything was in good shape and the noises were nothing to worry about. That was at 55,000, I'm at 90,000+ today, and everything is still tip-top.

 

Its your car, do what you want, Im just telling you what I've experienced.

 

On another note. Man my car runs SO MUCH STRONGER in this cold weather, in NC, after a long summer, you easily forget how fast the car is in the winter. I GOT SUBI LOVE.

[jlefavour]

Thanks for the info guys. The farm tractor analogy is quite accurate and helpful.

This car is bone stock, and appears to have been driven relatively easily. The straight cut gears explain the lash. Didn't realize this transmission had straight cut gears...actually, I didn't realize that any street legal vehicle since the 1940's had straight cut gears. Can anyone explain the logic? The only reason you'd go this way from a design perspective would be to handle a LOT of torque and power... a lot more than this car has...I'm further confused here because a friend of mine used to race subarus and advised that the transmission is the weak point of the powertrain, so apart from noise, what do the straight cuts give me?

 

On the spinning noise, I have less than 40K miles, so I'll definitely bring it to the dealer for a look.

 

It seems I've drifted a long way from honda country.. There's a lot to love about the cars' performance, esp in the snow, but I drive it relatively easy, and plan on keeping it relatively stock. You guys are frieghtening me with talk of tranny rebuilds. I'm used to oil changes and timing belts only until at least 200K. :-)

[vr4Legacy]

I wouldn't be too concerned about longevity. You need to remember this is an enthusiast site, and ALOT of people on here have modded cars that are driven harder than they were designed. And of course you are going to see more threads about how to fix a problem or complaining about a problem because most people don't start a thread that says "My car is doing great!" the old "squeaky wheel gets the grease" deal.

 

I am at 73k on my bone stock LGT, only thing other than normal maintenence I have replaced is the brakes at 60k, and that was premature on my part, because they could have easily gotten another 15k, but I was going on a long road trip and didn't want to risk it.

 

As a reference, I put 115k on my 98 impreza (bought used with 90k) with minimal maintenence, and 50k on my '05 impreza (bought new with 8 mi) with ZERO non standard maintenence.

 

I'd venture to say if you went to a Civic SI forum you'd hear a lot about "weak" components and early mileage catastrophes too, MOST from modding.

[Max Capacity]

Hey, just because my car see's redline a lot, and feels great in the top end of 3rd and will lift the front end to top out the shocks on the shift to 4th doesn't mean I beat in it.... does it. I also love the feel of my face skin being pushed back when I'm running through the gears. Another great feeling is the down shift into second and blow by grandma on the back roads.

 

If you want to stay stock and drive like a normal person, you should be fine. For the most part, for all the abuse we give these cars, as long as you keep after the oil changes and fluid changes you should be fine. Hey, I'm still on the oem engine and turbo.

[JoeFromPA]

jlefavour - I'm not an engineer, but I think the Subaru's transmission experiences a significant amount of shearing forces at the point of engagement compared to 2wd cars or vehicles with different AWD setups that transmit power through other mechanisms....

 

Mine sounds absolutely thrashy - to the point that I really dislike the sounds the drivetrain makes. This is at 55k miles and it hasn't gone away or gotten worse. I remember switching to AMSOIL 75w110 severe gear did lessen some of the noises though. Good gear oil.

 

One thing to note: If your car ever had a short shifter installed, they may have cut out alot of the sound deadening foam/rubber around the shift lever. That lets alot more gear noise in (I did it myself to my car, so I know).

[JoeFromPA]

I'll add one thing - My Suby has been a phenomenal car and my wife's DD for 2.5 years, since brand new.

 

I am considering taking the car up to ~80-90k and then trading it in for a low mileage 2009 Spec.B., which in my opinion has a much nicer drivetrain (transmission & diffs), a nicely done suspension, and a few other touches that I'd personally enjoy on a car we'd keep for the long-term. AFAIK, the 6-speed transmission does NOT make the same gear noises as the 5-speed, has a more robust clutch and throwout bearing, and is known to shift pretty nicely.

[Power6]

#1- gear lash noise is normal. As Max said, our gears are straight cut, which makes them a bit noisier.

 

No stock car has straight cut forward gears, and the Subaru 5MT certainly doesn't. If we did the gear whine would be as loud as it is in reverse! Have you heard a Subaru with straight cut gears swapped in?

 

The Subaru trans certainly has a good amount of whine for a stock trans, I have read that the helical cut of the gears is "mild" for more strength, lending a bit of the noise one might associate with a straight cut gear. Never seen for myself, but it sounds like a decent explanation.

[wpmarky]

Ok, not 100% straight, but they're straighter cut than most cars

 

http://legacygt.com/forums/showthread.php/straight-cut-gears-mythi-29067p2.html

[Max Capacity]

Seems to me the broken 2nd gear I had in my hand looked pretty straight compared to broken Honda gears I've held or my old 4 speed in my 340 Duster, 30 years ago.

 

Either way they are noisier than most tranny's.

[Power6]

Ok, not 100% straight, but they're straighter cut than most cars

 

http://legacygt.com/forums/showthread.php/straight-cut-gears-mythi-29067p2.html

 

Thanks for the info, makes sense. There is def more gear whine with this trans than other stock one I have heard.