Strange vibration under acceleration... driveshaft?

[wirestriker]

Hi all,
03 Noble 3R, 22k miles, 6spd, LSD
I am experiencing a strange low frequency vibration, seems to be from the rear right wheel.
It's more noticeable when cornering to the left at some high speed, in 3th or 4th gear, pulling with high boost around 3500rpm. (so I think it's torque related) More torque + more lateral g = more vibration.
Absolutely not noticeable when driving "normally"...just when climbing on a mountain road having fun or on trackdays.

It happens only when cornering to the left, loading the rear right suspension... the frequency could be around 7/10 Hertz.

I checked the hub nuts, they're updated (porsche) units and correctly torqued.
Damper/Spring is new.
All nuts and bolts are correctly torqued.
Wheels are balanced.

Could it be the driveshaft? Maybe worn joints? Moving the driveshaft does not show any particular slack.
Or is it something LSD related?

SFMBE (Sorry for my bad english )

[YellowShed]

I would recommend a check of the bearing on the link shaft - this can suffer from the heat of the exhaust.

YellowShed

[TuxMan]

Also check the engine mounts the back one on my car was in very bad condition through the heat from the exhaust !!!

[Gadgeroonie]

does the wheel bearing have any play in it ?

it could be the bearing that supports the driveshaft, can you pull it up and down ?

it could be the diff / gearbox

put the car on full lock and push it by hand one way then the other, then drive it round

[hollowpockets]

The exact same happened to my car last year. turned out to be the drivers side drive shaft centre joint was badly worn, it will get progressivly worse if you keep driving it. I'd get it changed asap. takes no more than an hour to change that outer shaft, it costs £120ish quid from a ford dealer or a dingbro, its just tricky to find a part number so i took the old one in and the matched it.

Graham

[RobP]

YellowShed said:

I would recommend a check of the bearing on the link shaft - this can suffer from the heat of the exhaust.

YellowShed

+1
Identified on mine by a clever little chap called Skip with a bit of kit that pinpoints vibrations.

[wirestriker]

Thank you very much for all the answers, I didn't even consider the driveshaft support bearing.

I'll check it in the next days.

[wirestriker]

Yesterday I removed the driveshaft bearing.
It's relatively a simple job:
-remove wheel
-remove damper
-remove caliper
-remove disc
-remove hub bolt (pneumatic tool required)
-remove 2 upper hub carrier hex screws
-tilt the hub carrier downward
-remove driveshaft (just push it through the hub, then pull)
-remove 2 x 13mm nut holding the support bearing
-remove the remaining part of the driveshaft just pulling or gently hammering with a soft hammer.

Then, using a press, remove the bearing from the short driveshaft.

Here's the result:




The bearing itself is in good condition, but there are some areas where the rubber is detached from the steel. Probably* this detachment associated with the high temperature (the bearing is just 1 inch from the exhaust) leads to strange movements and vibrations.

I replaced the bearing with part number 1094821, available from Ford Dealers at 75 euros. The part come from all the old Fiestas up to MY 2002, some Galaxy and Mondeo.
You can find the part even here http://www.teilesuche24.de/ersatzteile/zwischenlag...

• I said probably because yesterday because of bad weather I have been not able to drive fast nor cornering at high speed. However, I hope the problem is solved.

SFMBE

[Gadgeroonie]

Good job wire, is it worth making up a heatshield for our cars ?

[mgbond]

Nice one, added it to Noble parts.

Any chance when putting it back (if not already done so) you could get a phew photos linking up with the removal instructions.

Cheers

Bondy

[hollowpockets]

Im going to stick my neck out here and say you'll still have the problem, i did when i thought it was the bearing, hope im wrong but still think it'll be the drive shaft.

G

[RobP]

hollowpockets said:

Im going to stick my neck out here and say you'll still have the problem, i did when i thought it was the bearing, hope im wrong but still think it'll be the drive shaft.

G

Do you mean replace the whole drive shaft? Replacing the DS bearing on mine cured the problem. My symptoms differed slightly in that the 'rumble' was present all the time (straight-line,cornering, in-gear and in neutral), audible from about 20mph upwards.

[hollowpockets]

RobP said:

hollowpockets said:

Im going to stick my neck out here and say you'll still have the problem, i did when i thought it was the bearing, hope im wrong but still think it'll be the drive shaft.

G

Do you mean replace the whole drive shaft? Replacing the DS bearing on mine cured the problem. My symptoms differed slightly in that the 'rumble' was present all the time (straight-line,cornering, in-gear and in neutral), audible from about 20mph upwards.

Yes, i experienced rumbling when i was going fast and when turning in one particular direction, changed the half shaft with bearing as advised above but it was the main outer shaft joint that was shagged.

[wirestriker]

Just a quick post to reply to the topic, I will add some pictures about the job asap.

Last sunday I've been on a trackday, and I finally tried the car at the appropriate speed and lateral acceleration.

The problem (in my case) is solved with just the bearing pictured above, no more vibration/noises.

When I disassembled the suspension to replace the damaged bearing, I checked the driveshaft "manually" without any particular procedure, I just manipulated the joints to feel any excessive play or roughness, none of them was present.

[key750]

I return to this topic because I have a strange problem.
As MatteoWire had a problem with the bearing:

So I replaced the support and the bearing into the hub:

For 3 months everything worked fine but now the problem occurs again:
Yesterday while I was chasing an Evo 9 with 380cv in a long deserted mountain road ..... vrrrrrrr! vibration from the rear right in the left corners covered in acceleration. Problem is so marked that the mirror was vibrating!
Problem when the machine is really hot! after an hour "lunch break" everything worked fine again!
I took a picture but I do not seem to see cracks between the support and bearing:

I also put a plate to try to protect from the heat of the exhaust

Possible that the vibration is present only if the rubber support is heated? without it being deteriorated?
Has anyone tried to "ventilate" this critical area?
I thought I was open 30/40 shutters on the bottom to help the air ........

[R0162]

heat wrap and heat shield and protect your components.

[Gadgeroonie]

an aluminium shield should do the trick

[key750]

Gadgeroonie said:

an aluminium shield should do the trick

I have fitted alloy shield from 3 months and now problem is back on new bearing :-(

Thank you.

Nobody here (in Italy) knows our car and you are the only help I can get.

Edited by key750 on Tuesday 25th September 11:39

[sundance002]

It sounds to me like it could be the differential bearings, when you put load onto that side it cause the vibration.

Lift the back of the car and turn the rear wheel, see if you have movement or noise. I could be wrong, but it sounds very like the problem I had which turned out to be the Diff.