Mystery Vibration

Hi folks, was wondering if anyone would be able to shine some light on an issue I’ve been having with my 2006 2.5i Legacy wagon. I bought the car 6 months ago has 234,000kms on it now. Have changed a few items on it since then (spark plugs, coil pack, lower ball joints, sway bar bushings & sway bar drop links) normal for a used car. Also did an engine oil, transmission fluid and rear diff oil change 3 months ago.

 

So the problem is I can feel a vibration in car through the front end/centre of the chassis. The vibration is present when I’m driving above 50km/h and when I’m at idle. But only when I’m in gear, when I knock the car into N or P the vibration stops. It also pulls slightly to the left on the highway. I’m thinking something is up in the transmission because there is some hesitation when taking off and when I’m slowing down to a stop sign or traffic lights there is a slight knock coming from just below the gear stick at about 10-15km/h. Also it sometimes erratically shifts up a gear when I’m driving around the neighbourhood or in a parking lot. This was more noticeable in the winter time I changed the AT fluid and added Lucas Slip stop, this helped a bit but not much so I put it down to the AT fluid just being cold.

I read a few posts on people having issues with CV axles and transmission mounts causing vibration. I checked the transmission mount last night, it seemed pretty solid as I could barely make the transmission move at all. I did notice a torn inner CV on the Driver side, I should hopefully have that fixed this week but doubtful it’s causing the vibration at idle. (They are OEM CV axles)

 

So basically I’m just wondering if anyone has had a similar issue, if so what was it or if people think it might be a few different issues all happening at once. Thanks in advance and sorry for the essay!

Check motor mounts and the front control arms for worn bushings?

Check the carrier bearing for play in the propeller shaft. There will be movement but it should take some effort to make the shafts move.

If the vibration is present also at idle when the vehicle is stopped then it's either the engine or the torque converter that's acting up, but check the engine mounts first since if they are getting bad then you can get strange side effects.

 

I'd check the compression of the engine for peace of mind and while at it also replace spark plugs.

Thanks for the replies folks!

 

Checked the engine mounts last night, front end on ramps and jacked the engine up slightly (wooden block under the oil pan) and the car started to raise. Also use a small pry bar to shake the engine a bit engine seems pretty solid. So I took a video of the engine as I was cycling through the gears and turning the A/C on and off too. Check it out on the youtube link below.

 

I'll get a better look at them this weekend when i'm changing out my CV axle and I'll also get a look at the centre carrier bearing and control arm bushings.

 

What fluid did you put in?

Castrol Transmax synthetic multivechile ATF