Club 80-90 Forums

Really peculiar cyclic vibration that I'm getting with the SA at about 60 to 70 mph on the motorway, but not always...it's worse on smoother roads!
I've replaced all the front wheel bearings with FAG kits (correct end-float too), had all the wheels balanced, new CVJ's on the N/S driveshaft (shot too bits - rattling both ends) all of which have improved things by degrees, but it still has this low-frequency "thrumming" that you can feel coming up from the floorboards and the seat and then up the column to make the wheel buzz! About 6 seconds per vibration cycle, I guess and ruddy tedious.
There's no wheel shake, which is what makes me think that it's coming from out back...
Sound familiar to anyone?

When one of my rear wheel bearings went the drone varied depending which way I was turning. I found that when it was on the inside it went quieter and the outside louder. Jacking the back up and spinning the wheels showed a marked difference left to right too.

Vibration between 60 and 70 sounds like classic wheel balance...vibration through steering wheel is usually fronts and through vehicle is usually rears. I would jack the rear of the vehicle up and spin both rear wheels just to make sure you not got a tyre going out of shape..
IAN

I was stood in the tyre fitting bay chatting to the lads as they were doing it (keeping an eye) - all good to less than 5g. There's no steering wobble, it's a strange shudder that comes and goes and you can feel it going right through the bus. Weird.
I may have a lumpy tyre then.

I find some of our motorway surfaces leave a lot to be desired. Could it just be rutted tarmac?

Cruz wrote:I find some of our motorway surfaces leave a lot to be desired. Could it just be rutted tarmac?

Hmmm. It's pretty bad when you clatter over the joints in the concrete slabs ( like when going south on the M25 from J11). I wonder if I'm getting wheel flutter from a tired rear damper?

I know this sounds a little silly but did the good old boys in the tyre shop do the wheel up properly check your wheel nuts these guys tend to use impact wrenches with torqued wobble bars and they think thats ok never use a torque wrench but if the wobble bar is knackered ........

I only suggest this as had a wheel come off due to the highly skilled technichians at Kwik-Thick!

It does sound like a rear wheel / bearing issue the other thing to check is the Big hub nut loose it should be done up to 450Ft/lbs which is very very tight but most people dont have a Torque Wrench capable of measuring that amount