Two-Mass Flywheel failure - anyone else suffered this? - PeachParts Mercedes-Benz Forum

Greg in Oz · #1 06-21-2006, 04:44 AM

Has anyone suffered a dual mass (two mass) flywheel failure? With the gearbox currently out of my 1990 190E-2.3 Sportline 5-speed to replace the clutch, I discovered that the two halves of my dual mass flywheel have separated due to the failure of the eight pins that should hold it all together. The annoying aspect of this is not just the fact that it has failed, but that the list price for a new flywheel from the dealer is $2516.23 AU ($1.00 AU is approximately $0.75 US).

Has anyone else had a similar failure in a car with one of these flywheels? For more details and pictures see my thread about the clutch problems at New issue with 5-speed manual in W201 - difficult shifting (flywheel photos in post #11).

t walgamuth · #2 06-21-2006, 05:37 AM

so what is the idea with the dual mass flywheel?

cant the bolts be renewed and just go on with it?

i think my favorite machinist could figure a way to repair that one.

too bad you are down under.

tom w

kidMoBile · #3 06-21-2006, 07:53 AM

Greg:
When I was sourcing my donor 86 300E 5-spd to swap into my 95 wagon (no, not yet....sitting in driveway), my brother in law (BMW fan....leased a M coupe when it first came out...now owns a 95 M3) mentioned that it was great that the car has a single mass flywheel because the earlier duals were prone to the type of failure you have seen with yours, at least on BMWs. He had read of a few cases of this happening on BMW forums.
Sorry to hear about the big bill.
Good luck.
Brian

mbdoc · #4 06-21-2006, 08:14 AM

Here in the USA..MB part number 102-030-31-05 has a list of $900...With about 4-5 hrs labor....add the price of a complete clutch...$450-500.

Greg in Oz · #5 06-21-2006, 08:12 PM

Tom,
The dual mass flywheel is effectively two flywheels coupled by springs and a damping mechanism. The primary mass (which includes the starter ring gear) is bolted rigidly to the crankshaft. The secondary mass is that to which the clutch is attached and thereby provides the drive to the gearbox. In the case of the 4-cylinder M102 up to +/- 40 degrees of movement is allowed between the two masses (up to +/- 15 degrees on the 6-cyl M103 & M104). This "soft" coupling is intended to remove vibration and noise from the driveline and to improve smoothness, particularly at low engine speeds. Unfortunately, repair it is not so straight forward as replacing bolts (they are actually rivetted pins). I actually have access to a machine shop and we investigated the possibility of a repair but decided that the labour involved would be extensive and the end result questionable. The holes for the pins which have sheared have elongated due to movement around the broken pins and would therefore need to be enlarged and larger pins fitted. Other parts such as the bearing between the two masses is worn. I decided that for such a critical component of the car it was not worth it.

Brian,
As you mention your '86 M103 still has a conventional flywheel. MB introduced the dual mass versions in late '89 for the '90 model year (except on the performance oriented 190E 2.5-16 which retained a conventional flywheel with a weight well under half that of the dual mass). When I discovered mine had failed I looked at the possibility of fitting a conventional flywheel. Studying the EPC revealed that whilst the same crankshaft was used on all the 2.3 litre M102 engines, the gearbox input shaft and guide tube were shortened to accommodate the thicker dual mass flywheel. I liked the idea of a lighter conventional flywheel providing a slighty more "sporting" drive as whilst the dual mass is very smooth its huge mass and the momentum it carries means gear shifts cannot be rushed.

M.B.Doc,
A102 030 3105 is indeed the correct part number for the flywheel which replaces the original A102 030 2605 flywheel fitted to my car. Hopefully the new part number indicates a design change that will hopefully prevent a repeat of the same failure. The prices you quote are similar to those I have been quoted to get the parts directly from Germany. The $2516.23 my local dealer quoted me for a flywheel (and the $445.30 for a clutch disc and $495.80 for a pressure plate) just goes to show how much we here in Oz are being reamed up the you-know-what by MB on parts prices. Thankfully I don't also get reamed on labour as I do all that myself.

Thanks for the replies,
Greg

t walgamuth · #6 06-21-2006, 08:33 PM

perhaps you could bolt them together solidly.

tom w

Greg in Oz · #7 06-21-2006, 09:00 PM

Quote:

Originally Posted by t walgamuth

perhaps you could bolt them together solidly.

tom w

Tom,

On the surface that may appear to be a solution, however the two masses bolted solidly together would behave quite differently and present the engine with a flywheel that is too heavy. Remember that since the two masses are elastically coupled, the engine is not presented with a flywheel that is simply the sum of those masses. It is actually a far more complex system that is the result considerable analysis. The clutch disc for a conventional system also includes shock absorbing springs in its hub. Those springs are absent in my clutch as the "elasticity" of the dual mass flywheel takes care of that.

Greg