• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

240 Violent wheel shaking on braking

I see overheated front brakes all the time. Usually it's from large aftermarket wheels. Once in a while it's out of adjustment rear drums. Fluid contaminated rear drums is also a great way to destroy the fronts.

Whenever I detect the driver has been going too fast, or has mods, I am never surprised to find heat glazed front rotors and cracked pads, and wheel vibration.

Another rant: failed u joints onifted trucks... damn driveshaft angle is so far off it destroys u joints! Not anybody's fault but the owner.
 
never ever seen a bearing race wear like that... interesting.
what would be the cause and what would be the effect? Did the worn bearing race cause the rotor warpidge? Or did the warped rotor cause the wear on the bearing race?
 
never ever seen a bearing race wear like that... interesting.
what would be the cause and what would be the effect? Did the worn bearing race cause the rotor warpidge? Or did the warped rotor cause the wear on the bearing race?

I've seen races that look like that before, on trailers and cars that did not move for a long period. I would be curious to know if it's the case here.
 
Ok, so

Lateral Run-Out: Rotor wearing away/down perhaps uneven beyond tolerances ( .002 " )

Thickness Variation: Rotor is poor quality or has over heated/worn uneven ?


Is this correct ?

That's a very good question. I'm reading up on it right now.
 
Thickness variation is usually a buildup of pad material on the rotor. Coming to a hard stop, staying on the brakes, part of the pad compound can transfer to the rotor. Over time that can buildup and cause some variation and a surge will slowly develop when you are slowing down. Completely normal, pad choice may have some effect on it.

Runout is usually related to hub runout issues, machining tolerances slipping when the rotor or hub are made, rust/corrosion between the two, incorrect torque sequence, etc.

That bearing, that is an odd one for sure. Yeah, kinda has the look of having sat for a while, kinda has the look of a hard impact when being installed, kinda has the look of being a little tight, but not a solid indicator of any of the three exclusively.
 
Bearings were packed well with grease. I want to say when I installed the 4 years ago or so when I did the coilover conversion that one never felt quite right. The longest the car has ever sat without moving was two weeks while on a vacation. Up close it almost looks like the spots are collapsed voids like a bad casting. I do not know how that is possible in a machined and hardened race.
 
With damage like that I'd go with all new bearing surfaces.
I replaced the outer bearing but sadly I did not replace the inner bearing. I am accepting of the fact that this may be a stop gap measure. Really just need to make it into the new year and I can give the Volvo the attention that it needs.
 
Rollers and races were replaced, although with National brand bearings since that was all the local autoparts store had on hand. Had to have the car back together for the commute to work today.
 
Torqued to 85 ft-lbs while rotating the hub. Loosened all the way. Finger tight +1/8 turn to line up the castle nut with a hole.
 
Roller bearings don't like being too tight, better a smidge loose or you'll burn a bearing, spin it and ogg out the hub so it won't hold the race.

There's two holes btw, one vertical and horizontal so you can fine tune it a bit.
 
Torqued to 85 ft-lbs while rotating the hub. Loosened all the way. Finger tight +1/8 turn to line up the castle nut with a hole.

Eeeeeeeeeeeeeeh, I just did one today, the Bentley book said, 41 ft-lbs (while rotating the hub) and go back 1/2 turn.

But whatever.
 
I promise they are loose. I have the hand strength of an 11 month infant so my finger tight is more like an elastic waist band on the sweats of a 500lb couch potato.
 
85 seems tight to initially set them, but as long as you were rotating the hub while doing it, then back off and snug up as you did, most likely it'll be fine. Even on the Dodge it's a similar method.
 
Back
Top