DriveShaft Vibrations 1994 C220

While driving I had a SEVERE!!! Vibration that felt like it was coming from behind me. I thought it was the U-joint but when I put her up on the jacks I noticed that the front Flex Disk was just about destroyed.
Hopefully this has saved me several hundred dollars. Obviously I need to replace the front Flex Disk, should I also replace the rear Flex disk?
The Drive shaft Support (or as my British Haynes calls it Propeller Shaft Support) Center Bearing does not "feel gritty" There is movement in it like the support is allowing the drive shaft to flex up and down. Is this normal? It doesn't take much to move it; it's definitely not stiff. I just have no idea how stiff it should be.
Any thought how long does this job take with hand tools? Might have to reacquire my air compressor and impact wrench, it took 2 hours to loosen up the Exhaust bolts (most of the time spent trying to figure out how to get at them and removing the heat shields) and 5 minutes to drop it out.
Thanks, Hoping to order parts in the morning, install in the evening or tomorrow.
Thanks, Dave
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My sources seems to tell me that the mercedes drive shaft is best serviced my someone with proper balancing equipment...
I hope this is bunk and Tiger tells us we can do it ourselves...
I have a shop in Seattle that will repair/restore mercedes drive lines for about $275US including the flex disks and U joints.
Marty
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The driveshaft itself is superduty... only reason it might be a problem is center bearing that might go bad... but hey, both my cars have 200.000 miles and I never changed the driveshaft yet.
You are right on track about flex-disc. When bad, the vibration is just horrid. As far as the rear flex-disc, just inspect it, if you see serious crack then you have to replace it. My suggestion is loosen the bolt for the rear one... slip it out on one side... if all the sleeves where bolt goes through are solid, then it is fine...
However, like you said... if I gone that far, I might as well change it! Yep...
Flex-disc will go bad many times before the driveshaft go bad... Since you took out your exhaust and the shield that covers the driveshaft... inspect it... tighten up the bolts. If you feel alot of play in the bearing, then it is probably shot.
No regular shop can replace the u-joint instantly, it needed to be cut out and reweld a new one in... then it needs to be balanced. It is all precision work. Rebuilt driveshaft runs $275+ alone. I think that shope in Seattle is called Driveline... they are reputable business.
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I was able to get the old flex plate out last night, after dropping the transmission support, actually wasn't that hard... Removing the flex plate was at least 33% easier than most since 2 of the bolts had fallen out. This proboubly led to the failure. My Haynes didn't call for Locktite, but I don't see any reason not to use it, any thoughts?
Also my Haynes only calls for torquing these to 44 foot/lbs. This seems a little light to me. The Nuts and Bolts that came with the flex plate don't feel like they are matched. like they are purposefully cross threading. Does this make sense? The old ones were the same way.
Tonight, I'll put it all back together and go for a test drive, I hope. I'm leaving the rear alone. It looks good.
Thanks, Dave
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If you reuse the old bolts, then I would definitely use the Loctite. I would put loctite on new one too even though it won't need it. It feels tension because it is a compression nut... meaning it will hold the tension as it is tightened.
The torque sounds right... you can apply a bit more but not much more... maybe 50 is fine. It is the bolt/nut design factor.
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There really is no reason to over tighten these. The bolts and nuts only hold the flex plate in place and do not really need to hold much force, they just need to keep it in place (ie Snug).
Marty
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I finally got to test drive at 12:40 this morning... The vibration is gone while accelerating and decelerating; however there is a slight vibration when braking. I didn't get around to doing the rear disk, not sure if that will take care of it. One thing I forgot to do was check the holes in the yolks for wear. The "tabs" on the old disk show definite signs of distortion and wear.
When I stopped to back into my parking spot, the ABS light came on. When I released the brake it went out. Any new thoughts?
Thanks, Dave
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Check your brake pad. Vibration when braking is most likely to be your brake rotors slightly warped.
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Last night I pulled the old flex disk which was 33% easier than the re-installation since 2 of the 6 bolts just weren't there. Though the Haynes I have doesn't say anything about it I added loctite to the threads, I can't see any reason not to.
Both the original and the new nuts and bolts feel like they aren't matched, is this the German form of a locknut? Has anyone else had this issue.
Tonight I'll reinstall the transmission bracket, and exhaust and take her for a test drive.
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