I am getting strong vibrations from the front. They start mildly at around 40 - 45 mph, develop when driving at 50 mph and than dissapear at around 60 ' 70 mph. The steering wheel goes nuts and the whole front suspension fees loose. Tha car is a 1990 850 with 63t miles on the clock and still has original springs, shocks and all other front axle components appart from replaced (OEM) upper arm bushings and 1 tie rod end. I reballanced the wheels and they are ok. I feel the vibrations from the floor and through the steering wheel.

Another issue is a strong clunking sound when accelerating and decelerating, actually when stepping on the gas pedal and lifting the foot off while the car is driving. The car has automatic gearbox.

Can anyone suggest what are the most likely causes and cures for this.

vibration is most likely upper control arms...........unfortunately your thump issue on acceleration sounds like the driveshaft...............new arms and new driveshaft.......

Ok.

The first issue: Strong vibration from the front.

Some common possible causes (There maybe more):

1. Bent wheel. Resolution = Get wheels ckecked and repaired if needed.
2. Poorly balanced wheel. Resolution = Get a ROad Force balancing of the wheels.
3. Thrust arm bushings shot. All the gel came out of the bushing as it cracked. Resolution = Very common issue. Replace Thrust arm bushings with BMW OEM bushings. Make sure they are Pre-Loaded.
4. Tie rods loose. Resolution = Tighten the Tie Rods to proper torque. Loose tie rods can result in a catastrophic event.
5. Uneven tire pressure. Resolution = Check all tires for correct and even air pressure.
6. Wheel bolts too tight. A lot of places use an Impact wrench to tighten the wheel bolts. Resolution = Loosen the wheel bolts and then retighten them by hand to 70 ft-lbs.

Issue 2: Clunking noise from the rear as vehicle weight shifts.

Some common possible causes (There maybe more):

1. Broken Rear Shock mount. This is a common problem and a repair kit is available from BMW. Resolution = Park the car in a location where the sunlight hits the trunk. Open the trunk and remove the side carpets (CD Changer and the Jack side). Look up through the rear wheel wells. If you see any light pass through, the shock mounts are cracked. If that is the case, purchase and install the BMW rear shock tower reinforcement kit (A lot of welding involved and better left with the pros.
2. Worn Shocks. The shock levels are hitting the bump stops. Resolution = There is not a very good way to test this without taking the shocks out. Test and replace shocks as needed.
3. Worn Boots and Bushings of the rear wheel carreer. Resolution = Replace the bushings and boots. They are very hard to find and replacing them is very labor (= cost) intensive.

I hope this helps a bit.

Ok.

The first issue: Strong vibration from the front.

Some common possible causes (There maybe more):

1. Bent wheel. Resolution = Get wheels ckecked and repaired if needed.
2. Poorly balanced wheel. Resolution = Get a ROad Force balancing of the wheels.
3. Thrust arm bushings shot. All the gel came out of the bushing as it cracked. Resolution = Very common issue. Replace Thrust arm bushings with BMW OEM bushings. Make sure they are Pre-Loaded.
4. Tie rods loose. Resolution = Tighten the Tie Rods to proper torque. Loose tie rods can result in a catastrophic event.
5. Uneven tire pressure. Resolution = Check all tires for correct and even air pressure.
6. Wheel bolts too tight. A lot of places use an Impact wrench to tighten the wheel bolts. Resolution = Loosen the wheel bolts and then retighten them by hand to 70 ft-lbs.

Issue 2: Clunking noise from the rear as vehicle weight shifts.

Some common possible causes (There maybe more):

1. Broken Rear Shock mount. This is a common problem and a repair kit is available from BMW. Resolution = Park the car in a location where the sunlight hits the trunk. Open the trunk and remove the side carpets (CD Changer and the Jack side). Look up through the rear wheel wells. If you see any light pass through, the shock mounts are cracked. If that is the case, purchase and install the BMW rear shock tower reinforcement kit (A lot of welding involved and better left with the pros.
2. Worn Shocks. The shock levels are hitting the bump stops. Resolution = There is not a very good way to test this without taking the shocks out. Test and replace shocks as needed.
3. Worn Boots and Bushings of the rear wheel carreer. Resolution = Replace the bushings and boots. They are very hard to find and replacing them is very labor (= cost) intensive.

I hope this helps a bit.

This helps a lot, thank you!

1st issue:
1. and 2. -checked that and got the wheels ballanced. Not road force though but ballanced ok.
3. I replaced them with BMW OEM about 1000 miles ago. Didn't do the pre-loading at first, but a month after fitting the new bushings I raised the car again, losened the trust arms, supported the wheels and raised them to the height where they should be if the car was on the ground, and tightened the bushings again, but without torque wrench. I tightened them as much as I could with a normal wrench. Do you think this is ok? I didn't notice any damadge to the new bushings in the mean time.
4. Tie rods -will check again, but I checked them by hand while the car was on a jack and didn't find any loose ones. However, I tried jerking the wheel left-right and there is small play. I also have play on the steering wheel. I guess I should adjust the box first, yes?
5. Checked the pressure - ok.
6. Last time I had them torque wrenched to 120 Nm. I think this is 88 ft-lbs. Do you think this is too much?

What about the lower control arm - alu wishbone? I can rotate fairly easily with my hand while the car is on the ground. Is this normal and what is the indication of necessary replacement?

Issue 2:

1. Will check that.
2. Worn shocks - most likely the source of my problem bacuse rear left shock has leaked. I just didn't realize it could make such noise.
3. Worn boots and bushings on rear wheel carrier - I am not sure what you are reffering to, but I did replace all rubber mountings on rear trailer arms, all with BMW OEM:

33 32 1 090 452 - very expensive
133 864 - wasn't really necessary
879 - also wasn't really necessaryWhat are other usual worn out parts and necessary replacements on rear axle?

vibration is most likely upper control arms...........unfortunately your thump issue on acceleration sounds like the driveshaft...............new arms and new driveshaft.......

Checked the drive shaft and all seems ok. Rear left shock has leaked and I from what ahmed says I guess this is the problem. If that isn't the issue than I would suspect the diff rubber mountings... what do you say?

could also be a bad center bearing/guibo........diff mounts should be easy to check...

I once had such a noise on my E32 750iL and it turned out to be the rear tranny mountings.

For the front vibration another possible cause:

Are you running after market wheels or BMW OEM wheels with the wrong center bore size? If so you may need hub centric rings.

I once had such a noise on my E32 750iL and it turned out to be the rear tranny mountings.

For the front vibration another possible cause:

Are you running after market wheels or BMW OEM wheels with the wrong center bore size? If so you may need hub centric rings.


I am running aftermarket wheels - Keskin KT4 8.5x18" and 9.5x18" but they have plastic rings that are still in good shape.

I am running aftermarket wheels - Keskin KT4 8.5x18" and 9.5x18" but they have plastic rings that are still in good shape.

to make sure they are not the reason I'd mount an OEM set temporarily and check if the symptoms disappear. I would almost dare to bet that it is the wheels.

I will try that. Thanks