Untraceable vibration from rear wheels

[anonymous-user]

The initial message was deleted from this topic on 03 August 2021 at 19:22

[aka_kerrly]

Have you checked the prop shaft coupling, I'm not 100% clued up on ls430 but ive had a few bmws and when the doughnut bush on the prop starts falling apart you get that vibrating floor sensation

[tektas]

Had something similar with my Mercedes. Check the differential and propshaft for play.

[anonymous-user]

Ah the propshaft donut. I've got it booked in for Thursday for the local garage to have a look. Hoping it's something simple.

[TechBod]

Had the same on a Honda CRV...

It turned out to be the brake caliper slide pins sticking...

When they stuck, the friction material constantly pressed against the disc which then heated up, thinned out the grease until the bearings started to 'overheat' and caused a vibration...

Once the friction material had worn away slightly from the disc, the disc cooled down, the grease regained its viscosity and the bearings cooled and the vibrations disappeared.

Only a thought, but it was always above 60 mph when the heating of the friction material against the disc was at its 'critical' phase.

[anonymous-user]

That may be worth a look too. Recently changed pads all round which appears to have made this worse....

[HealeyV8]

Put money on it being a UJ in the prop. I had this and checking it myself I just couldn't get enough purchase with just my hands and arms. You need the torque of the engine to get the play from worn UJ.

[stevieturbo]

Should be easy to trace ?

Put car on ramps, remove wheels and run up to speed.

That eliminates a substantial rotating mass that could cause a vibration, and will point in a more specific direction. Propshaft is very possible.

Or if the vibration is gone, try different wheels.

[anonymous-user]

Thanks for all of the replies!

I'm in Poland, Getting anything done is an absolute mission as mechanics don't seem to be very good at diagnosing problems. A ramp installed at home is on the cards for next year.

I've tried different wheels and the vibration is still there.

Is a propshaft a big job or simply a matter of finding a new part and fitting it? There does seem to be a slight "shunt" in the drivetrain when applying power and letting off the throttle.

[stevieturbo]

Get it in the air and look.

[markcoopers]

Switch the wheels front to back if possible to see if the issue moves....thus eliminating or focusing on wheels.

Prop and cv and uj joints all possible, but are you sure the discs or even the wheel is not bent? I have a slight bend in a wheel rim and while they balance, it causes a tiny vibration at motorway speed so needs to be fixed.