Vibration while driving on 300E Flex disc suspicion - PeachParts Mercedes-Benz Forum

loepke72 · #1 02-25-2010, 04:59 PM

Most definitely. Not only is there an imbalance due to the missing bolt, but the flex disc can also move around a bit there.

Mike@Exclusive · #2 02-25-2010, 07:58 PM

theres metal inserts in the flex discs. Check them for play. I usually replace them once I see dry cracks in them.

Ferdman · #3 02-26-2010, 08:06 AM

Replacement bolts/nuts should come with the new flex disc. Be sure to check the condition of the front flex disc too. You will need large open end wrenches to loosen the driveshaft coupling so the driveshaft will telescope to allow sufficient clearance for rear flex disc removal. If for some reason the driveshaft halves separate be sure to reassemble using the match marks or the driveshaft may be out-of-balance. It's likely that you will need to lower the exhaust system to work on the flex disc and driveshaft coupling. This is a DIY job, but time consuming ... at least when I did it.

samiam44 · #4 02-26-2010, 12:27 PM

I'm suprised to hear the vibration starts so low speed.

Are your wheel brgs tight? Any play in the idler arm? Motor mounts good?

tinypanzer · #5 02-26-2010, 11:37 PM

For God's sake, don't wait to fix it. That can fail with rather dire consequences.

JordaanDMC-12 · #6 02-27-2010, 12:43 AM

loepke72- Thanks, that's what I needed to know, really want to get that screw back in there asap.

Mike@Exclusive- I haven't checked the metal inserts but from a visual standpoint it looks good with no cracks.

Ferdman- Thanks for the info for the DIY Ferdman, I'm probably going to be taking this to an indie though

due to the lack of time I'm going to have in case I mess something up. Hopefully it just needs the bolt and I can be on my way.

samiam44- This may be a really stupid question but are idler arms only in front? I know for a fact that the vibration is coming from the rear, yeah it starts at about 25-30 and it's a pretty good vibration, how do you check if the bearings are tight?

tinypanzer- I want to get this fixed ASAP because it feels as though it's getting worse and I've seen the damage that a flex disc can cause when it fails, I'm just hoping replacing the missing bolt will cure this, why it's missing to begin with is totally beyond me too, I've I knew the owner before the person we bought it from, I'd like to give them a piece of my mind!

My dad thinks it might be the transmission mounts but it feels as though it's coming from where the flex disc is.

ps2cho · #7 02-27-2010, 02:55 AM

Quote:

Originally Posted by tinypanzer

For God's sake, don't wait to fix it. That can fail with rather dire consequences.

The dire consequences are more along the lines of freeway safety if it disconnects. There is no issue with it "falling out" because the transmission mount bracket stops it from falling.

But don't confuse this with it being okay to leave it. You do not want the disk to crack and leave you without any wheel power. Get it replaced asap.

It is very easy to do. It is even easier if you support the transmission and remove that crossmember I mentioned as it gives you 5x the room to access the disk. The Flex disk is a general maintenance item that seems to need to be replaced anywhere from 45-90k miles. I replaced mine on my 300TE 30k miles ago and I am already starting to see some small gaps emerging between the bolts so they do wear.

Give the throttle a solid blip at low speeds and you should hear a metallic "clunk" if it is loose in any way.

Ferdman · #8 02-27-2010, 07:14 AM

I wouldn't consider flex disc replacement a routine maintenance item. The rear flex disc failed on our 1992 300CE at 137,000 miles; while the rear flex disc on our 1995 E320 is still fine at 165,000 miles.