Hi all, I just noticed this today as some friggin moron pulled into my lane causing me to slam the brakes on hard.

The left front appears to have a grinding/metal crunch noise under high braking pressure.

I have a feeling it might be a warped rotor or worn suspension bushing in the left front. I can feel it under my left foot. Is it possible that front left shock is going bad and is letting the tire rub? It doesnt seem like a rub as I can feel it in the floorboard and in the brake pedal.

This only happens during very hard braking.

I would like to know what it could be and if I should worry about it right now.

The feeling almost feels like the pad is grinding into the rotor, but the rotors look fine.

Could it be a defective pad?

I hope that this is something that is not major for repairs, and if its a DIY job, I'd love to do it myself to save on the labor.

I've done work on my other cars, from brake jobs, tuneups, radiator flushes and valve covers, but have never gone into major repairs. Though working on American cars and in the one case an old 1980 MGB I had, is easy as hell, I would prefer to know if its more than a DIY, so I can schedule to take the car to my mechanic.

If it has to deal with replaing rotors/pads, I am sure can handle that, or simple tuning work, but when it comes down to dismantling major stuff, don't let me near a wrench hehe. I can take it apart, but putting it back together is the harder part.. I don't want to end up with any extra nuts or bolts after I'm done.. hehehe

Please advise, I would like to get it taken care of ASAP.

Also want to know if motor mounts/tranny mounts would cause my shift knob to rock a bit under accelleration and braking. if I hold it, it doesnt move. I was thinking the tranny mounts may be shot.

I checked for play in the drive shaft and all seemed solid.

My main concern is the brake issue, but as long as I may have to take it to the shop, I figure I'd get the mounts done if they are needed.

Other than that the car drives and feels great.

Thanks for any help,

Alon

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'92 300CE
Metallic Black (Blue Flaked) on Creme
Clear Corners
Black Grille Insert
78k Miles

Future Upgrades:
Sportline Suspension
17" AMG Monoblocks or EVO II's
94-95 Tail Lights
Euro Headlights
Chip
AMG Exhaust

Click here to Go To My 300CE Page

This sounds like the Anti-Lock brakes are "kicking in". When they decide to take over, it feels like something is grinding your car to it's death.

Good luck,

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Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, manual, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Larry,

Thanks for the reply, do you think it could be signs of impending failure, or is it normal.

Should I change out the pads/rotors just to be safe? Maybe change to steel braided brake lines at the same time?

Would you recommend doing anything or just doing nothing?

Also what about that tranny gear selector rocking back and forth during accel/braking? Any ideas? I think it is a bad mount, or the drive shaft is moving backwards and forwards due to wear? Let me know.

Thanks
Alon

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'92 300CE
Metallic Black (Blue Flaked) on Creme
Clear Corners
Black Grille Insert
78k Miles

Future Upgrades:
Sportline Suspension
17" AMG Monoblocks or EVO II's
94-95 Tail Lights
Euro Headlights
Chip
AMG Exhaust

Click here to Go To My 300CE Page

Alon,

If I was an unscrupulous mechanic and you were in my shop, I would be thinking, "Cha-Ching" and dollar signs would be spinning in my eyes.

What you described is normal ABS behavior. Nothing to worry about. I remember when it first happened to me -- felt like I was pushing through, and snapping, metal rods or something. Very odd sensation indeed.

Eric Silver
89 260E

Hi,

If you are still worried that it may be more than the ABS cutting in, you can remove the wheel and check the pad thickness through an aperture in the caliper. Check out the Do It Yourself section on this site for 300E pad change if you need to go this route. Best of luck and I hope its just the ABS.

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Ian Anderson
87 300E

The pads appear to be very new. very thick actually. My thinking is that if Larryis correct, then it might just be normal. I havent noticed any rotor damage being done due to the grinding feeling.

Nobody answered the question about the gearshif going back and forth. Mine does the same, but i can only feel it by hand (not much movement). I think it has something to do with the mount. I think we will have to post it as a separate topic if nobody picks up on that.



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Dmitry
90' 300CE
17" Lorinsers RS90
Brulen mufler
Clear Blinkers

If you're not sure what ABS feels like, find a dirt road, or a road with loose sand or some such on it, then mash the brakes at moderate speed. Oh, yeah, do this when there is NO TRAFFIC, and don't forget to steer! The ABS will engage, and you can experiment with the sound and feel. It won't hurt anything on the car.

I do this occasionally to relieve boredom...

I also "test" ABS on each car during the first few snowfalls each year, to gauge the traction available, or lack thereof, and to remind me what the ABS feels like. It's different on each car.

BTW, when the ABS on the Suburban engages, the pedal drops fast and it feels like it will NEVER stop! 6,000lbs of IS hard to stop on slippery roads

My $0.02

Good luck, and safe motoring
BCingU, Jim

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'96 E300D 60k mi (wife's daily ride)
'95 Audi 90 120k mi
'92 GMC Suburban 139k mi
'85 300SD 234k mi (my daily ride)