trany modulator - PeachParts Mercedes-Benz Forum

joro · #1 04-08-2008, 12:11 AM

Would someone be so kind to photograph and post a picture of the modulator on the 722 tranny?
Im down there but dont know what im looking at.
Thanks

kerry · #2 04-08-2008, 12:14 AM

Look on the DIY wiki's, there are pictures.

joro · #3 04-08-2008, 12:17 AM

can you provide me a link?
thanks

kerry · #4 04-08-2008, 12:22 AM

http://www.peachparts.com/Wikka/Trans722VacMod

RML · #5 04-08-2008, 12:38 AM

Quote:

Originally Posted by joro

Would someone be so kind to photograph and post a picture of the modulator on the 722 tranny?
Im down there but dont know what im looking at.
Thanks

I was hunting down the elusive modulator myself last weekend. I finally had the time on a nice day to get under the car. It is tucked up alongside the left side of the tranny, above the pan. Mine is green, but was dirty so I did not recognize it at first. I found it hard to get to as it not as accessible as I had hoped. Next time I will try to get the jack stands up a little higher so I have more room to move around. If you have someone that can wiggle the black vacuum line from above, it may help you to locate it. The black line goes into the modulator.

Now that I located the bugger, I need to test if the vacuum hose connecter is cracked, or if the modulator is bad. I do not hold vacuum in that line, so pulled the black line from the vacuum source above to see if it made any difference. It didn't, so I need to do some more testing.

Good luck.

Richard

pawoSD · #6 04-08-2008, 12:40 AM

Here's a question....how do you replace the trans modulator? How does it come off?

Pete Burton · #7 04-08-2008, 12:44 AM

Quote:

Originally Posted by pawoSD

Here's a question....how do you replace the trans modulator? How does it come off?

2 M6 allen head screws (5mm hex) hold a retaining plate. remove those, and pull modulator straght out.

RML · #8 04-08-2008, 12:58 AM

Quote:

Originally Posted by Pete Burton

2 M6 allen head screws (5mm hex) hold a retaining plate. remove those, and pull modulator straght out.

Thanks. That was probably going to be my next question. Did you find it hard to get your hands into that small space?

I took that cap off and turned the T adjusting handle clockwise two notches to see if it would make a difference in my harsh 1-2 shift. The T fell off in my fingers and I had to reinsert it. Should that have happened? It did not end up making any difference.

Richard

pawoSD · #9 04-08-2008, 01:50 AM

Quote:

Originally Posted by RML

Thanks. That was probably going to be my next question. Did you find it hard to get your hands into that small space?

I took that cap off and turned the T adjusting handle clockwise two notches to see if it would make a difference in my harsh 1-2 shift. The T fell off in my fingers and I had to reinsert it. Should that have happened? It did not end up making any difference.

Richard

Its a lot easier to get at/replace on a W126 than on a W123....tunnel is bigger and the trans sits a little lower so the modulator is in plain view. Its quite nice.

I will be replacing my modulator soon.

RML · #10 04-08-2008, 07:00 PM

Quote:

Originally Posted by pawoSD

Its a lot easier to get at/replace on a W126 than on a W123....tunnel is bigger and the trans sits a little lower so the modulator is in plain view. Its quite nice.

I will be replacing my modulator soon.

Hmmm! This would be a good excuse to find myself a nice W126.

Richard

John Schroader · #11 04-08-2008, 11:03 PM

I found that replacing the modulator was a pretty tough job. The allen head screws stripped out. Then the fun began. Eventually cut a 2 1/2" hole in the tunnel to access it from inside. Made using an EZ out possible. Was advised that I could not easily lower the transmission to gain access. Was later told by someone else that that is exactly what he did (and it worked). Hope I never have to replace it again, but if so - I now have an access hole in my tunnel.

RML · #12 04-08-2008, 11:12 PM

Quote:

Originally Posted by John Schroader

I found that replacing the modulator was a pretty tough job. The allen head screws stripped out. Then the fun began. Eventually cut a 2 1/2" hole in the tunnel to access it from inside. Made using an EZ out possible. Was advised that I could not easily lower the transmission to gain access. Was later told by someone else that that is exactly what he did (and it worked). Hope I never have to replace it again, but if so - I now have an access hole in my tunnel.

Yowzer! Thanks for the heads up, John. This tells me to be really careful and cautious if I try to replace mine. But first I need to establish where the problem is.

Richard

pawoSD · #13 04-08-2008, 11:56 PM

Cutting = potential rust zone!

I hope my allen screws don't round out....I'll be extra careful. At least mine isn't hidden....makes it much easier.