I have replaced everything in the front end suspesion / brake system along with new stub axles and bearings. Coil Springs, Shocks, Rotors, 10 control arm and shock bushings, upper and lower ball joints, inner outer tie rod ends. EVERYTHING. I even replaced the rear bearings inner and outers along with shcoks and 4 Michelin tires. Alignment and everything. I still get a steering wheel shake at around 55. It tracks fine and is very smooth up to that point. What am i missing???

Cheers,

Snookfever / Martin

 

Are your wheel nuts properly tightened? Have you had the wheels balanced? Is the steering rack mounted securely? I have read reports of the mounting nuts becoming loose over time! Is the steering column secure?

These are just some basic suggestions, but in my thinking, it's the best place to start.

 

You don't mention wheel balancing but you must have done this.

Here's an idea. Perhaps you have one wheel that's not balanced. Using the spare wheel swap one of the fronts then try it. Then swap the other and then try it. Then do the back wheels. If it cures it you know that wheel is bad.

The other thing is perhaps your disks are warped or not seated properly. Perhaps a wheel is not on straight.

Bearing in mind I have not ridden in your car could it be an engine misfire? See if selecting a lower gear changes the affect.

I am buying a spare coil to see if swapping each coil in turn makes the engine smoother. It's very smooth at tickover but the car has a perceptible low frequency shake. This might be normal.

 

Bent wheel?

 

Usually a vibration at a given speed is the result of tire/wheel imbalance. The best thing to do is find a Road Force Wheel balance machine that puts load on the wheel/tire. The technician can then use the high spot of a tire and mount it to a low spot on the wheel (weight wise) to eliminate vibration. This is ideal in the case of a bent rim, it also accounts for manufacturing tolerance (or lack thereof). Ideally the two tire/wheel combos that have the least road force (assuming asymmetrical tires) can be put on the front.

I used to own a wheel/tire company and we used the Hunter GSP 9700 machine for this.

Also, your subframe v-mounts or lower fulcrum bushings could be bad in addition?

Check the balance first though.

 

I have had to use the load force balancer on my XK8. But even that didn't work on one wheel. All balancers mount at the hub, but one wheel proved to have bolt holes that were not perfectly concentric to the hub. That wheel had to be replaced.

 

Thanks Everyone For Such Quick Responses. I have tried everything except obviously what the actual problem is!!! I know the rack is tight as I had to losen and drop a little to replace both inner tie rod ends. The shake in the front end has been there from day one when I got the car with 135k. Hence, this replace everything to get rid of it plus I want to keep the car for a while. All the coils where replaced with Lucas OEM out of the UK. Including all suspension parts where Lumefurder, Billstein or UROSpare parts. The one thing I think it could be is the rear wheel hubs. The car was humming from the rear and one of thefirst things I did was replace rear wheel seals and inner outer bearings ALL by Timken the original OEM. The hum went away. However the Hubs metal shaft did appear burnt and a little worn. I went ahead and re-used them and like i said the hum is gone. Both front and back still have a slight play up and down 6 to 12 oclock. More so in the back. SD96XJ6L, I will look into the Road Force first as thats only 60 bucks and I believe the fulcrum bearings are okay. Where is the subframe V-Mounts located exactly?

Snookfever

 

Bye the way if this helps: The car is smooth as butter until I reach 55mph and settles down somewhat at 65-70mph. However, is still there at higher speeds just not as bad as 55mph to 65mph.

Snookfever

 

Also, I believe every car has a tire that works best for that particular car. I choose Michelin Defenders because of the 90K tread warranty. However, is there a better tire like the Pirelli Cinturato P7 All-season Plus or a Different Michelin the Michelin Premier A/S instead of the Defender? This shake has got to go!!!!! Uuuugh!!!

 

The shake is almost definitely wheel balance, and a load force balance is the next step.

 

I want to thank everybody as the Hunter GSP 9700 wheel balancer was the answer and COMPLETELY resolved the wheel shimmy. Thanks everybody.

Snookfever

 

my X300 developed a horrible vibration and drone that kicked in at 60 km/h and got worse as speed increased, then on slowing down would abruptly disappear again below 60.
It was a different problem - no steering shake
It was a worn hanger bearing in the middle of the 2-piece driveshaft. Once replaced, perfect
Just a thought...

could you have a slightly sticking set of brake pads on one front disc which are causing this? (Just clutching at straws)

 

Judging by post#11 there's no need to clutch at straws.