PeachParts Mercedes-Benz Forum - View Single Post - Replaced transmission modulator...it had ruptured.

pawoSD · #1 10-19-2008, 12:07 AM

Late this week, like thursday or so, I noticed my transmission was suddenly shifting very "soft"....very unusual as I usually have it set to shift quite briskly....it wasn't real bad so I didn't do anything till today, I did a vac test with my vacuum tester on the modulator line, it fell to 0 right away, didn't hold any vacuum at all.

So I tested it underneath to be sure it was the problem, leaked down there too. I had bought a spare about a year ago, so I removed the two 5mm allen bolts, pulled it out with channel locks (wiggling it out), was met by a cascade of fluid.

I then noticed that the little plastic pushrod thing that fits in ahead of it was broken off inside.

I managed to fish it out with a piece of wire, thankfully. Even more thankfully, I had bought a spare just to have one. (They're only $2.55 or so)......So I cleaned it all up, put the new pushrod thing on the modulator, slipped it in place, pressed it in, tightened the allen bolts, added a little fluid, and took it for a spin. Shifts perfect! Just like before except maybe even a bit better! The new modulator holds vacuum without any loss at all. Its cool to apply vacuum to it when its in your hand, you can watch the little piston move in and out and see how it works....those crazy engineers....

Total repair time, a little under an hour. I like when things go fairly smoothly! And my shifting is back to its firm old self.

Whoever says these automatics are "hard to keep shifting right" or "don't last as long as the manuals".....are dumb. Simple as that.

I've adjusted mine maybe 3 times in the past 5 years/70,000 miles.....and all I've done repair-wise is change the fluid/filter each spring.....and the modulator I just replaced. Thats it. Very very reliable.