5MT Jerks On/Off the Throttle

[maddog39]

Hey everyone,

Ever since I purchased my car in May of 2012, the car would jerk one or more times coming on or off the throttle. The car can be in any gear, and the clutch is always fully engaged when this occurs. Being in a low gear, high in the rev range, and letting off the throttle, will greatly exacerbate the issue. It does not matter necessarily how quickly I let off the throttle.

Basically it feels like a really rough transition from acceleration to deceleration or vice versa. When transitioning from deceleration to acceleration, often times the jerk will be accompanied by a clunking noise from the transmission.

Roughly 100-200 miles ago I had the transmission and rear diff fluids changed with Subaru Extra-S gear oil. While I saw improvements, this phenomenon still occurs gets quite annoying after a while, especially in slow moving stop and go traffic.

Has anyone else encountered and issue like this before? What could be the root cause and is there a solution?

Thanks!

[Boxxerace]

And your Outback is a non turbo 04 model, yes? This eliminates at least one of the issues.

[frogsthatmoo]

Check this thread

Go look at your outback's rear differential bushings and tell me if they look like the first picture in that thread. I had started a thread a while ago asking the same question and it ended up being these bushings. A few days ago I replaced them with solid poly bushings and holy ****, I love my car now.



These are the bushings I put in, they are SuperPro.

[Boxxerace]

Are those the rear swing arm bushings?

[frogsthatmoo]

Differential bushings.

[maddog39]

Yes, my car is an NA 2.5L. But awesome, I'll go outside and check during my lunch break and take a picture. Thanks for the input so far, I'll check back in later.

[CSFiend]

Originally Posted by frogsthatmoo

Check this thread

Go look at your outback's rear differential bushings and tell me if they look like the first picture in that thread. I had started a thread a while ago asking the same question and it ended up being these bushings. A few days ago I replaced them with solid poly bushings and holy ****, I love my car now.

These are the bushings I put in, they are SuperPro.

How difficult did you find that job to be? My rear diff bushings are shot; I've been thinking about putting bushing inserts in versus replacing them.

[susiemk]

Originally Posted by frogsthatmoo

Check this thread

Go look at your outback's rear differential bushings and tell me if they look like the first picture in that thread. I had started a thread a while ago asking the same question and it ended up being these bushings. A few days ago I replaced them with solid poly bushings and holy ****, I love my car now.



These are the bushings I put in, they are SuperPro.

I see the bushings arrived OK - how bad was the job?

[frogsthatmoo]

Thanks again SusieMK! I meant to send you a message letting you know I got them. It went swimmingly actually. I left the cross member in and just drilled the old bushings out. Then I used a pair of vise grip pliers to pull them out completely. A rounded file cleaned out the old rubber really well. Then I just greased up everything I could touch.

Used a jack to level/support the diff and then lined up the bushings. I couldn't push them in by hand but I used a massive pair of channel locks that we have that open to about 6 inches or more and just used those to shove the bushings in. Overall took less than two hours.

Fantastically easy. Will be doing it again soon for my brother's car.

[frogsthatmoo]

Originally Posted by CSFiend

How difficult did you find that job to be? My rear diff bushings are shot; I've been thinking about putting bushing inserts in versus replacing them.

If they're already shot it might be worth replacing. In my case, the upgraded bushings used the stock "metal ring" thing that's in there. Some require you drop the cross member to have the old ring/bushing pressed out.