Author Topic: Instruments: Removal, Cables  (Read 6529 times)

Richard Madison

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Instruments: Removal, Cables
« on: March 12, 2003, 21:29:14 »
Tried to remove the speedo ('71) to fix the fluttering needle and screeching. Have the tach out. The center unit is loose and pushed aside with cables still connected.

On the tach, the nut holding the bracket was finger tight but the same nut on the speedo is tight (maybe the threaded post is corroded). I tried open and closed wrenches, a socket, but there's no maneuver room. I tried a blind spray of WD-40 but the nut ain't moving. The speedo won't push in to relieve the pressure. The meter won't move at all. Any suggestions on how to get the nut off?

Another issue (and maybe a warning to others). I thought the tach cable had some slack so I could pull the unit partially into the car then remove the cable. NO, the cable did not move...instead the end connector (1 inch white metal piece) came off the cable. Getting a new cable so this was not a disaster.

The problem of the "no move" tach cable may be due to some work previously done on the firewall. The cables pass thru a grommet but this area was slathered with old black rubber goop that held the cables tight to the wall. Doesn't look original.

I removed the rubber goop and will be installing new grommets. Anyone know if the rubber pasty stuff is original?

Richard M


'71 280 SL, Tobacco Brown, Cognac interior, Tan top, Jump Seat, 80K orig miles, NYC.
1969 280 SL, Tunis Beige, Euro Model (Italy).


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Re: Instruments: Removal, Cables
« Reply #1 on: March 12, 2003, 21:50:15 »
Hello Richard,
Try putting on some thin leather gloves if you have room. They will give you more grip and a little more torque.

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


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Re: Instruments: Removal, Cables
« Reply #2 on: March 13, 2003, 09:23:34 »
Richard - try a squirt penetrating oil instead of WD40 and if you are right handed try to tighten that nut a fraction of a turn first to free may have a little more torque turning right.


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Re: Instruments: Removal, Cables
« Reply #3 on: March 13, 2003, 10:50:35 »
    While you are ordering the firewall grommets you should also examine the rubber seals aroung the instrumnets. There should be rubber seals around the tach, speedometer and the center instrument panel. These seals sit between the instruments and the dash. Mine were old and dried out.
Good luck,


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Re: Instruments: Removal, Cables
« Reply #4 on: March 22, 2003, 08:49:14 »
Push in on the bracket (toward  the instrument) where the stud passes through, while turning the thumb nut. The pressure of the bracket on the thumb nut serves to lock it in place. This worked for me.
Your hands will heal in within a week.