Wobbling when accelerating

[sirius99]

Well well, i will go on to check driveshafts again if i have some time.

One thing i didn't mention....just noticed it yesterday while braking hard downhill ride at about 50mph....strong wobbling like i described it....dont see the connection!?

 

[manfrotto]

Well well, i will go on to check driveshafts again if i have some time.

One thing i didn't mention....just noticed it yesterday while braking hard downhill ride at about 50mph....strong wobbling like i described it....dont see the connection!?

Very strange -If that is the case, then I wouldn't expect it to be a drive shaft issue, unless you have two issues producing the same symptoms?

 

[DXX]

Has anybody checked the obvious?
Wheel bolts, bolted spacer bolts (if any) and tyre inner sidewalls.

 

[manfrotto]

Has anybody checked the obvious?
Wheel bolts, bolted spacer bolts (if any) and tyre inner sidewalls.

Good point - also centering rings if wheel centre bore is bigger than 65.1mm, and any thing to stop wheels bolting flush with brake discs etc. (although @sirius99 says he has had new wheels and tyres just fitted, and issue was before this)

 

[DaveD]

One thing i didn't mention....just noticed it yesterday while braking hard downhill ride at about 50mph....strong wobbling like i described it....dont see the connection!?

My daughter's BMW started doing the same and I suspected warped discs but I checked them with a dial test indicator and they were perfect, I then checked the control arm bushes and both sides were totally knackered, lots of slack in them. I changed the control arms and it cured it.
I wonder if the same issue could cause your wobble under acceleration too, as your van is front wheel drive?
Worth having a look, with a pry bar.

 

[DXX]

My daughter's BMW started doing the same and I suspected warped discs but I checked them with a dial test indicator and they were perfect, I then checked the control arm bushes and both sides were totally knackered, lots of slack in them. I changed the control arms and it cured it.
I wonder if the same issue could cause your wobble under acceleration too, as your van is front wheel drive?
Worth having a look, with a pry bar.

You’re right about using the pry bar, too often they get checked by hand.
Putting a vehicle in for an MOT is cheaper than booking in for a dealers diagnostic session, of course you need to lap it up if it fails.

 

[DaveD]

You’re right about using the pry bar, too often they get checked by hand.
Putting a vehicle in for an MOT is cheaper than booking in for a dealers diagnostic session, of course you need to lap it up if it fails.

You'd think so - my daughter's car had passed with no advisories a week beforehand, they said the wobble under braking would be warped discs and the control arms were fine!
She told them I'd checked the discs with a DTI but they looked blank at her, I doubt they knew what one was.

 

[DXX]

You'd think so - my daughter's car had passed with no advisories a week beforehand, they said the wobble under braking would be warped discs and the control arms were fine!
She told them I'd checked the discs with a DTI but they looked blank at her, I doubt they knew what one was.

Fewer and fewer mechanics who know their stuff. Dept of Trade and Industry may have been mentioned the tea time discussion.

 

[sirius99]

Has anybody checked the obvious?
Wheel bolts, bolted spacer bolts (if any) and tyre inner sidewalls.

Wheels and tires are ok. Spacer bolts? No idea where they are

 

[sirius99]

My daughter's BMW started doing the same and I suspected warped discs but I checked them with a dial test indicator and they were perfect, I then checked the control arm bushes and both sides were totally knackered, lots of slack in them. I changed the control arms and it cured it.
I wonder if the same issue could cause your wobble under acceleration too, as your van is front wheel drive?
Worth having a look, with a pry bar.

having a look, with a pry bar? : ) how does that work?

 

[sirius99]

My daughter's BMW started doing the same and I suspected warped discs but I checked them with a dial test indicator and they were perfect, I then checked the control arm bushes and both sides were totally knackered, lots of slack in them. I changed the control arms and it cured it.
I wonder if the same issue could cause your wobble under acceleration too, as your van is front wheel drive?
Worth having a look, with a pry bar.

Understood, found a video. Could be the problem, since it is responsible for stability when accelerating and braking?
Does the vehicle need to be jacked up for the check?

But.....this will not make the described sound!?

 

[sirius99]

I did a quick check under load.
The drive shaft on the right side has about 2 mm of play in the longitudinal direction and rattles slightly when it hits the stop.
The engine mount on the left no longer looks very good. See photo
Control arm i will check later...

 

[DaveD]

Understood, found a video. Could be the problem, since it is responsible for stability when accelerating and braking?
Does the vehicle need to be jacked up for the check?

But.....this will not make the described sound!?

It's worth trying the identify play in the control arms with weight on the wheels and off the wheels if you can, ramps are useful if you've got some for checking with weight on.
It's also worth using a pry bar because the forces generated on control arm bushes when you accelerate and brake are far in excess of anything you can replicate with your bare hands.