Most peculiar suspension / drivetrain issue

[BuyPirelli]

Hi folks,

This post may be a bit long winded, but please bare with me. Have had this issue for about 9 months now, or 4,000 miles. My Mondeo ST2220 drives great, steady as a rock, and in a straight line it has no bangs or clonks.

 

However when turning (60%+ steering) I am getting a knock / grating sound from the front left of the car with some weird steering kickback feel, it doesn't happen all of the time, but it does more often than not, and its harshness varies.

 

Symptons;

 

1. Sounds almost identical to driving on snow, literally. When it snowed, I couldnt tell the difference between the car or the snow! Though sometimes it is more of bang. Can't tell if its metal on metal, or rubber?

 

2. The car can sometimes kangeroo up and down, and subsquently rocks side to side. As soon as I straighten the wheel its fine.

 

3. The car HATES accelerating even moderatly with the wheels turned sharply, it seems to wheel hop and clatter like no mans business. Makes blasting out of junctions or roundabouts difficult.

 

4. The feedback through the wheel feels like somethings twisting, however its not proportion to the amount of steering, and it seems to go trough cycles. For example, you feel it, then the feedback seems to get stronger, it climaxs, then starts from the beginning. It in turn accompanys the sound of snow crunching, which I would describe as a low thud.

 

So, theories;

 

1. Driveshaft, CV joint or diff. Either of them, would this explain the trouble accelerating with the wheels turned? Will a car kangeroo if only one wheel is getting power? Does this explain the physical movement the car is experiencing?

 

2. The wheel is loose, ok maybe not the wheel, but the hub is. Obviously I've tested them, as have two garages and physically everything looks spot on. All solid as rocks, all nuts and bolts are tight, nothing seems out of place. However a dodgy hub or something would explain the madness.

 

3. Top mount or upper spring broken and no-body has noticed? Would this hhave the above symptons? If so, why does the car drive perfect in a straight line?

 

Well there you have it, all I can think of. I've spent 45 minutes on two ocassions checking both sides of the car with the wheels off. My local indy has had the wheels, hubs and brakes off to get a real good look but everything seems fine...

 

Come on lads, give it your best.

[Tony]

It's a write off...........

 

No, only serious......

 

I'll try that again...... Engine mounts play a major part during these yaw moments, have these been checked?

[BuyPirelli]

Erm no, but I will do, though I dont suspect that!

 

The thing that gets me is all the suspension is solid, not worn, loose or perished in any way. So the wheel cant really be falling off, even if thats what it feels like. That leaves drivetrain I think, but hey, what do I know.

[Tony]

Engine mounts directly influence the drive train.... Is your car a manual?

[andyelcomb]

Sounds to me as though you have a partially seized CV joint. That would give most, if not all of your symptoms.

 

Try jacking the car on just one front wishbone, put it on lock (turn the steering wheel - DON'T push the road wheel as you can knacker the power rack's seals that way) and then turn the road wheel by hand and see if you feel any roughness or binding.

 

Check the other side the same way, but you do need to try and do it with load on the suspension so you aren't doing it on full droop.

[BuyPirelli]

Yeah Tony it is a manual. I am learning towards CV joints, but they are expensive to replace on a whim.

 

Theres a Ford specialist near me I may try out. Keep the advice coming chaps.

[Tony]

Worn CV joints click on full lock under load..... do you get any noise?

[Rich]

First thing that sprung to mind was CV joints, I had similar symptoms on my Mondeo and it was this.

[boxbrownie]

Check your CV joint first.......try full lock in reverse gear.

[BuyPirelli]

Worn CV joints click on full lock under load..... do you get any noise?

 

Yes, sounds like driving over snow! A lot thudding noise. Not ruling it out, but I had a CV joint go on another Mondeo of the same generation and that sounded different, like a light clicking noise.

 

I have tried the full lock in a car park trip and sometimes it does it, sometimes its quiet as a mouse. Do we think it would be inner or outer joint, how do you tell?

[andyelcomb]

Still sounds like a CV fault to me.

 

Lightly worn ones will just click, but if you've got a split gaiter and its got rusty inside, then it can still partially seize without being specifically worn and sloppy enough to click.

 

The only true way to find out is to try and replicated the binding joint statically and then take the driveshaft out and manipulate the joint fully by hand.

 

Or, maybe you can cut the clip off the big end of the boot, peel it back and have a look inside. If there's any solid looking grease, or none, or rusty etc then that's your problem.

[BuyPirelli]

Still sounds like a CV fault to me.

 

Lightly worn ones will just click, but if you've got a split gaiter and its got rusty inside, then it can still partially seize without being specifically worn and sloppy enough to click.

 

The only true way to find out is to try and replicated the binding joint statically and then take the driveshaft out and manipulate the joint fully by hand.

 

Or, maybe you can cut the clip off the big end of the boot, peel it back and have a look inside. If there's any solid looking grease, or none, or rusty etc then that's your problem.

 

I do think its a CV joint too, it was my first thought actually but its good to get backed up on it. If it were suspension then it would bang going over bumps, which it doesnt.

 

The gaiters are solid with no leaks, but I suspect this doesnt stop them from failing.