Author Topic: Tach question  (Read 854 times)

GW230SL

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Tach question
« on: March 21, 2022, 18:34:33 »
Recently had the tach out to repair my light switch, all back in, but the tach needle is now on the wrong side of the resting pin. When you crank it up it the needle stops of course on the pin. What happen? Thanks
Greg W Smith, Pawleys Island SC
1965 230 SL
2018 AMG GTC
2018 AMG GTR
2021 AMG GLS

Kevkeller

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Re: Tach question
« Reply #1 on: March 24, 2022, 13:31:27 »
What exactly do you do to the unit?
1970 280 SL

ejboyd5

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Re: Tach question
« Reply #2 on: March 24, 2022, 18:00:54 »
Sounds like a mechanical issue with the tachometer having been jostled while out of the car and the needle becoming displaced. Try removing the tachometer again, turning it dial downward and gently shaking it in an attempt to jump the needle to the correct side of the peg. Failing that, the lens may have to be removed to properly orient the needle. Removing the retaining bezel and re-crimping it is not a big deal, but it must be done carefully to avoid dents or bulges in the metal.

naristodemou

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Re: Tach question
« Reply #3 on: March 29, 2022, 06:03:37 »
Yes, I think you would have to remove the lens and gently move the pointer end over the peg. Check it thoroughly that is does not go past the peg again, if it does it means that the needle is not straight but bent, gently straighten it and recheck. It should stop firmly on the peg when released.

Use a new O-ring seal when refitting the tacho back in its place.

Nicolas
Nicolas Aristodemou
Nicosia - CYPRUS
280SL Auto 1970 US spec (W113), 380SL 1982 R107, Citroen DS23 Pallas 1973, Triumph TR4 1963, Triumph Stag 1973, Mini Cooper S Mk1
1965, Jaguar 3.8 Mk2 1962, VW Beetle 1978 Karman Converible, 1987 Ferrari 328GTS

Pinder

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Re: Tach question
« Reply #4 on: March 30, 2022, 00:10:27 »
if you were able to jump it over the post while out maybe before you take the lens off try jostling it back by holding it glass face down and some creative movements.
1970 280 SL Light Ivory DB 670. 4 Speed manual shift no AC Limited Slip Diff.

GW230SL

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Re: Tach question
« Reply #5 on: March 31, 2022, 00:49:00 »
Thanks for the suggestions, I'll pull it out and try these ideas.
Greg W Smith, Pawleys Island SC
1965 230 SL
2018 AMG GTC
2018 AMG GTR
2021 AMG GLS