Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: twistedtree on April 23, 2015, 02:11:28

Title: Symptoms of a bad transmission modulator?
Post by: twistedtree on April 23, 2015, 02:11:28
Other than sucking ATF back up into the intake manifold, are there any other symptoms of a bad modulator?

My transmission seems to be much more interested in up-shfiting than down-shifting unless I punch the gas such that I engage the down-sift switch under the peddle.  I have checked the trans pressures and they seem good with 10psi with the idle switch engaged, 40 psi off of idle, and 60 psi with the kick-down engaged (the three positions of the three-position solenoid).

I'm just starting to drive this car, and just starting to explore this particular anomaly, but welcome any insight anyone might have.
Title: Re: Symptoms of a bad transmission modulator?
Post by: ctaylor738 on April 25, 2015, 21:15:06
Well, you can put a vacuum pump/gauge on the modulator to make sure that it's holding vacuum.  I believe there is a gasket and o-ring that can leak, in addition to the diaphragm.

You can mess with the adjustment and see if it changes the behavior.  Here are some instructions:

http://mercedesdismantlers.com/16BoltInstallationInstructions.html

Cheers,

CT