Wheel bearing question - PeachParts Mercedes-Benz Forum

300ESUPER · #1 11-23-2006, 06:35 PM

I have a 1989 300E and I am doing a front brake job and the question I have is how tight do I put the I call it the tension bolt (beacuse it looks like the top of the battery terminal) against the bearing to hold the bearing, hub straight? Also what does the little copper thing do?

Thanks

Fab

Gilly · #2 11-23-2006, 06:41 PM

With the small bolt in that nut loose, first tighten it down quite hard while rotating the disc, then loosen it again. My rule has always been that you tighten the nut just tight enough that it won't loosen by hand, then lock the lock bolt. The small copper tab is there to (believe it or not) decrease interference noise on the radio.
Gilly

300ESUPER · #3 11-23-2006, 06:48 PM

Thanks for the rply but I have a question. What did you mean when you said tighten then loosen. Also how freely should the disc rotate?

Thanks

Gilly · #4 11-23-2006, 06:58 PM

First tighten the nut quite hard, to remove any excess grease from between the bearing surface and the bearing race. Rotate the disc as you are tightening it.The loosen the nut again. Then tighten the nut JUST tight enough so you can't loosen the nut by hand. You will need to try a few times to get it right, so don't rush this. THEN tighten the bolt that cinches the nut on to the car. You should be able to spin the rotor freely, but it won't sit there and spin for 1/2 a minute or anything, but should spin without any binding.
Gilly

300ESUPER · #5 11-23-2006, 06:59 PM

Thanks