Mercedes 6.9 Transmission Modulator Valve

[Star]

Evening All, I'm having transmission issues etc, and our local Gearbox Mechanic outlined to me that the diaphragm could be split, it's not holding any vacuum.
Questions
1 - Any idea where one could purchase one from?
2 - Also, would anyone have the original part No

Thanks
Starman

 

[Patrick_R]

Sean may b able to assist with this one?

 

[Star]

Many thanks Patrick

 

[sean sherry]

Is the Transmission having Hard Upshifts ? The Modulater's job is to regulate the Line Pressure. To correctly diagnose the Transmission is with an Oil Pressure Gauge and then a Vacuum Gauge at the inlet Manifold and then at the Transmission end. Anything else is an uninformed guess. To test the Modulator for vacuum leakage is with a Vacuum Pump. It should be leaner all the way up and down. As should be the Line Pressure .. Engine Idle. Probably 60 PSI to around 150 PSI
Reverse test will be much higher. Guessey games will cost you....A job for someone with the correct equipment An Internet search for a Modulator....using the Vin No. !!!!
Styria may have a used one you could just try ??

 

[sean sherry]

I should have said .... first pull the Oil Pan to see if the Clutches have failed..... first check... If so rebuild the Transmission.
And Michel, how was the Honda you asked about .. a clean Oil Pan ??

 

[Star]

Many thanks Patrick for the reply, apology for the delay in my response I've been away.
transmission sticks in first gear, gets into second then drops back to first driving slowly, will get into third and every now and then drops back.
I have the vehicle booked into a local auto transmission company ( company owner has a Mercedes 350 auto and seems to know all about them)
I did a test on the modulator and it doesn’t seem to hold pressure, I‘ve got hold of a second hand one that does hold pressure, come Monday I’ll know more re transmission company inspection test etc

 

[Star]

I should have said Many thanks Sean
my apology