Wobble at the front

[firezuki]

Howdy gang.  My 2007 Presara (taxi) has developed a bad wobble on the front end.  It feels like a drivetrain issue as it only does it under acceleration.

I've replaced .... wait for it  ....  both left and right CV joints .... all four engine mounts  ...... gearbox.  

It has two local mechanics baffled and has one ****** off cabbie.  

I have it booked in to Pedders on Wednesday morning.  

Has anyone had anything similar happen to them and if so, what bloody was it?

[jtfoto]

I'd be looking at wheel bearing/s or a suspect tyre next.

 

[firezuki]

No, it isn't either of those.  It only happens under load.  If it were bearings or tyres it would happen all the time.  

[trentmeyer23]

Just remember that when you accelerate in a FWD car, the front wheels are naturally trying to toe in. If there are any worn steering/suspension components or a poor alignment, the symptoms can become amplified.

[campbeam]

Previously read your post and been thinking about it. I would certainly like to know the solution.

Looks like you have had the usual causes already investigated and eliminated.

Just read this article so maybe the rotors and/or brake pads should be inspected.

http://automotivethinker.com/brakes-2/rotors-blank-vs-cross-drilled-vs-slotted-and-warping/

 

[firezuki]

Pedders put a GoPro under the car and they can't see anything wrong.  Bloody hell!  It's not the pads or rotors Campbeam or it would be happening only under braking or all the time.  The vibration only occurs under acceleration.  Otherwise you wouldn't know there was a problem.  It's very frustrating.  I still suspect the right hand CV joint even though it's been changed twice.  I don't trust Chinese stuff and whilst they were brand new, they weren't genuine.  

[trentmeyer23]

Might be worth getting some time on a chassis dynamometer. This will allow the drivetrain to get up to speed and also allow the technician to closely inspect the components in a safe/controlled environment.

[firezuki]

I've been Googling without any luck.  Does anyone know where such a beast exists in Perth?

[trentmeyer23]

Most performance/tuning workshops will have one. Some 4x4 diesel perfornance places will as well.

Otherwise known as a dyno. Just make sure they have the rolling road type and not the hub dynos.

[firezuki]

I'll try and find one Trent.  It is driving me bonkers.  I'm about to replace the car as my taxi (it's been outstanding and never fails to get a mention/question from passengers) and I want to give it to my daughter.  I really need to sort this problem.  I've spent about 4K so far in trying to eliminate what it could be.  So far, process of elimination hasn't worked.  

[trentmeyer23]

Throwing parts at a problem rarely works. The art of diagnosis is disappearing.

[firezuki]

In my case, most of those parts had done 650,000 kms so it wasn't as upsetting as it might have been.

But you're right.  No-one seems too interesting in getting to the bottom of it.  Very frustrating for me.  

[campbeam]

Hope the attached document is of some assistance. It is only a selected sample of the results.

You have replaced four mounts for engine and presumably the transmission. Suggest open the bonnet, rev the motor and watch for any engine movement. There should be none or very little movement. Also listen or look for any vacum leaks that may be causing the engine to miss or vibrate when under accelerating.

Next, you mentioned that you have replaced CV joints. Is that both outer and inner CV joints on both drive shafts?  

I would be [under the car] checking the drive shafts to confirm there is no play.

No harm in using injector cleaner as mentioned in the Google search.

Not sure how you can check the torque converter; maybe go to an auto transmission specialist.

 

Google Search Results vibration under acceleration toyota.doc

[firezuki]

It can't be the torque converter because I replaced the gearbox with a different torque converter.  Did it with old, does it with the new.  I still do feel it is an inner cv joint even though both sides are brand new.  All four engine mounts are brand new.  It's not fuel.  It has a sway, wobbly kind of feel under acceleration that goes away when you take the foot off. Everyone seems to think it is a CV joint.  I have replaced the right hand one twice.  Maybe it needs genuine?

[plshelp]

On 4/9/2016 at 3:45 AM, firezuki said:

It can't be the torque converter because I replaced the gearbox with a different torque converter.  Did it with old, does it with the new.  I still do feel it is an inner cv joint even though both sides are brand new.  All four engine mounts are brand new.  It's not fuel.  It has a sway, wobbly kind of feel under acceleration that goes away when you take the foot off. Everyone seems to think it is a CV joint.  I have replaced the right hand one twice.  Maybe it needs genuine?

hey, did you ever figure out what was wrong with it? i've gone through process of elimination as well but still nothing. 

My toyota aurion is doing the same (vibrating/shaking when i accelerate around 60-80km/hr) and stops the moment i remove my foot off accelerator.