Author Topic: Transmission modulator diaphragm replacement  (Read 4928 times)

twoods

  • Guest
Transmission modulator diaphragm replacement
« on: December 01, 2010, 17:29:23 »
I need help with if and how the modulator diaphragm can be replaced with the
transmission in the car. Any tips are appreciated.
Thanks

ja17

  • Full Member
  • Platinum
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  • USA, OH, Blacklick
  • Posts: 7410
Re: Transmission modulator diaphragm replacement
« Reply #1 on: December 01, 2010, 19:09:39 »
Hello,

The worst part of the job is removing the large mounting plate underneath the transmission. Some of the many 17mm bolts are above the exaust. An exhaust heat shield can get in the way also.   You may need to removle all the exhaust hangars and allow the exhaust to move down giving you a bit more room to work on the bolts.

After the cover plate is off, just follow the metal vacuum line from the engine down to the modulator. Do not disturbe the little square adjusting bolt and lock nut. You will see three 7mm or 8mm bolts which fasten the modulator housing to the transmission.  Once the three bolts are removed, the diaphram is easily replaced.  A bit of fluid may escape, but you do not have to drain the fluid. Be careful not to loose the spring when the cover is open up . The diaphram installs easily.  Most likely, no modulator adjustments will be needed.

Keep us up to date.

Joe Alexander
Blacklick, Ohio
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

twoods

  • Guest
Re: Transmission modulator diaphragm replacement
« Reply #2 on: December 06, 2010, 16:00:12 »
Received my parts and parts diagram from my friend and parts supplier Will Samples of S&S Imports in Dallas.
Moved the exhaust heat shield out of the way. The upper bolts are difficult. Found that taking the modulator off at the second bracket (11mm bolts) was easier. You can then replace the diaphragm out of the car and replace. No need to
drain transmission fluid. Car runs great. There was no need to adjust, shift points remained smooth. First time I have used the forum. Thanks for all the great information.

al_lieffring

  • Guest
Re: Transmission modulator diaphragm replacement
« Reply #3 on: December 06, 2010, 19:00:15 »
Did changing the modulator diaphragm fix the smoking problem you were working on in http://www.sl113.org/forums/index.php?topic=13727.0 ?

twoods

  • Guest
Re: Transmission modulator diaphragm replacement
« Reply #4 on: December 08, 2010, 21:53:01 »
 Yes that was the problem. After your reply I checked the vacuum line at the intake and found fluid. Also made sense because my trans fluid was very low.
Great call Al. Saved me from going into my head to search for a possible valve problem.
Thanks again.