96 W210 Front bearing hub runnout, Help - PeachParts Mercedes-Benz Forum

skhagen · #1 02-16-2008, 10:42 PM

I have a 1996 W210.
The front bearing hub had excessive runout on the driver side causing slight vibration. I bought a new set of hubs w/bearings installed along with new Brembo brake rotors.
When I installed the new hub I checked the runout and it was still not true.

Anyone have any ideas as to what else can cause this type problem?

Is it common to have to turn the rotors on the car? MB dealer says they dont turn rotors.

Chas H · #2 02-16-2008, 11:29 PM

You should review your measuring methods.
How much run out?

skhagen · #3 02-17-2008, 12:02 AM

Dial indicator and magnetic and the hub seated you can also see it with the rotor in place and bolted to torque spec. The run out was .026" it has a slight drag when rotateing the hub by hand. You can hear the brake pad rub at the point where its out. I only feel pedal pulsation when braking aggresivly at high speed on the initial pressure to the pedal.

Chas H · #4 02-17-2008, 12:22 AM

Did you check the face of the hub for run out before fitting the rotor? Check for swarf on the mating surfaces. That's alot of runout.

skhagen · #5 02-17-2008, 12:23 PM

Now your beyond my knowledge. but I will say that I did check the runout on the hub before running the rotor. It is out aswell. can the spindle be the probem?

Chas H · #6 02-17-2008, 01:03 PM

A bent spindle will not make run out. Do both old and new hubs have run out, measured without rotor?

skhagen · #7 02-17-2008, 05:54 PM

yes both have runout I am thinking of swapping the left and right hub. Im pretty sure it wont make a difference. Its hard to beleive that two (old compared to new) parts would having the exact same issue. but its there Ive verified it a couple times. The hub shows no more than normal bearing play on either side with the tire on. Im stumped.

The hub runout is not so bad but the system gets very exagerated when the rotor is in place due to the increase in diamater.

skhagen · #8 02-17-2008, 05:58 PM

The spindle was not discolored or spawled at all
the mating suface swere new since both rotor and hub were new no burs rust ETC.

Quote:

Originally Posted by skhagen

yes both have runout I am thinking of swapping the left and right hub. Im pretty sure it wont make a difference. Its hard to beleive that two (old compared to new) parts would having the exact same issue. but its there Ive verified it a couple times. The hub shows no more than normal bearing play on either side with the tire on. Im stumped.

The hub runout is not so bad but the system gets very exagerated when the rotor is in place due to the increase in diamater.

Chas H · #9 02-17-2008, 07:50 PM

Try tightening the bearing nut until the hub turns with a small amount of drag and re-measure the runout.

skhagen · #10 03-02-2008, 03:57 PM

Well, I did the dreaded runout test and as you suspected the bearings had not been preloaded. Its hard to comprehend that a the wheel bearing being loose can cause such braking and vibration issue. I pulled the brakes,rotors, hubs and repacked the bearings. (Bye the way the MB grease far outlives the lubrimatic high pressure grease.)
The rotor end play was mildly out of spec after adjustment. I have 15 k miles on the bearings and rotors. It s amaizing how durable the Brembo rotors are after being to loose and developing bad vibration issues.

I have a mild runout issue with the left rotor, about .003 in. None with the hub; at least beyond measurement with my tools, cost will keep em on the car awhile longer. They are very responsive brakes with EBC reds. As a result of being out of spec the pedal has mild pulsation when braking hard at Highway speed. The 50-60 MPH vibration is gone and the car I expect is back.

Thanks