Does anybody have any experience with the following on Mercedes? If so, please elaborate. Thanks.


Why Some Crankshaft Thrust Bearings Wear Out

Besides a clutch being out of adjustment, or even a clutch petal rider, there areother reasons why a crankshaft thrust bearing wears out. One of the causes of aworn out thrust bearing is a worn out or faulty torque converter. The main purpose of the torque converter is to multiply effective engine power to the transmission at low speeds, and to act as a fluid coupling at higher speeds in delivering torsional force from the engine to the transmission main body.

The problem generally stems from a worn stator assembly, which is either allowing too much end clearance, or the one way roller clutch is not holding. Thus, the stator is freewheeling between the turbine fins inside of the converter, causing excessive slippage. The stator is the element in a torque converter which must remain stationary, in order that the flow of fluid is redirected in an efficient manner from the primary pump to the turbine and back at lower speeds, thereby increasing torque, or power output. Its function is to redirect fluid flowbetween the pump and impeller, giving proper torque multiplication from the engine to the transmission.

When the stator wears and allows more than .050" to .060" end play, the multiplication of the converter becomes more difficult due to pressure loss in the converter, and then puts more torque load on the engine or forward pressure on the crankshaft. When there is constant or too much pressure on the crankshaft thrust bearing, the oil film becomes destroyed, and the wear pattern begins. Oneof the first indications that the converter is wearing is a sluggish acceleration of the vehicle, especially on take off.

I'm no expert and it sounds like you've got it pretty much figured... but how many miles on the converter, and has the fluid ever been changed?

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/showpost.php?p=831799&postcount=13
http://www.peachparts.com/shopforum/showpost.php?p=831807&postcount=14

Wear on the thrust bearing can be determined by checking the endplay of the crankshaft.
I think friction sufficient to affect acceleration would quickly wear out the thrust bearing.

Not sure about the stator wear issue. Pressure differential between the fornt half and rear half of the converter is a cause of axial load on the thrust bearing, though.

See this link for some more on the subject:

http://www.4secondsflat.com/Thrust_bearing_failures.html

__________________
Prost!

100k. Fluid changed every 30k