2009 Legacy GT rear axle issue?

[James_0541]

An odd one that I hope someone can help with.

After pulling away I occasionally get a loud 'bang' from the rear of the car, like something has just released, not all the time, just sometimes. It's quite violent though, especially tonight when I accelarated hard out of a roundabout. It generally happens after a couple of hundred metre's from setting off, but not thereafter.

Could it be the handbrake releasing?

Thanks,

James

[Axeboy]

Not sure it's the same issue, but is it an auto?

[James_0541]

Yeah, a five speed auto, not a cvt.

[Konan]

Can you feel anything too, or just a noise?

[James_0541]

Quite a violent knock, like something behind me has suddenly released a lot of tension. You can feel it through the car.

[Axeboy]

That box has a common fault, it should be the 5eat

There is a sensor that fails, I had the same, it's very harsh, usually just after pulling away harder.

You should have a fault code showing for it:

"5EAT sensor failure, often the Turbine Speed Sensor #2 (TSS2) triggering code P1710, causes harsh, banging shifts (like being rear-ended), erratic shifting, or the vehicle getting stuck in gear, common in 2008-2014 Subarus"

Edited by Axeboy on Tuesday 16th December 07:49

[James_0541]

Thanks for that, is just a matter of replacing the sensor, or is there more to it ?

[Axeboy]

It's taken as a pretty serious fix by many, but it's not that bad in reality.

Check that is the fault and code first of course. The sensor can be found online, I got one on Ebay, just search for P1710 sensor and you'll get hits. The cover on the box will need to come off to change the sensor and it'll need a fresh feed of genuine Subaru ATF which isn't cheap. Mine didn't like alternative oils.

Last, you'll need the gearbox to be recalibrated, which my local dealer did. It had to be done on a lift and it used the Subaru diagnostic software.

Sounds like a faff, but wasn't that bad really

There are quite a few YouTube videos of it and loads on the US forums as the box was used in loads of American models

Edited by Axeboy on Tuesday 16th December 08:39

[James_0541]

Thank you, appreciate you help.

Funny enough I bought two 4ltr cans of genuine Subaru ATF, with the idea of getting the transmission fluid changed. You're right, it's not cheap.