Pagoda SL Group

W113 Pagoda SL Group => Electrical and Instruments => Topic started by: grn280SL on June 01, 2008, 10:26:55

Title: Tach bouncing and making audible noise
Post by: grn280SL on June 01, 2008, 10:26:55

Fellow Owners,

I took a turn a little fast yesterday, and now my tachometer needle is now bouncing and there's an audible buzzing noise coming from the gauge cluster that gets louder as the rpm's increase.  What is this? What is the fix? Loose cable or broken tachometer?  

Thanks!  I want to get back on the road!

Title: Re: Tach bouncing and making audible noise
Post by: waqas on June 01, 2008, 12:28:45

This sounds like the Tach needs a rebuild. I had a similar issue some years ago and I had the Tach rebuilt from Overseas Speedometer (http://www.speedometer.com/). Noise was all gone. Another culprit might be the tachometer cable.

Here's a topic about someone else having a similar problem:
http://sl113.org/forums/index.php?topic=4622,play

Whilst we're on the subject, make sure you check your tachometer drive gear play. This gear also drives the oil pump. Excessive play could lead to gear disengagement, which would effectively switch off your oil pump (no oil pump = no lubrication = seized engine).  This has been discussed a great deal, such as these threads:

Excellent post by Joe Alexander somewhere in this topic:
http://sl113.org/forums/index.php?topic=3097,play

Replacement of thrust bushing:
http://sl113.org/forums/index.php?topic=4869,play
http://sl113.org/forums/index.php?topic=3952,play

Title: Re: Tach bouncing and making audible noise
Post by: philmas on June 03, 2008, 02:46:22

I had the same issue some years ago.Greasing the tacho seemed to have solved the problem, and no more screaming since then.

Title: Re: Tach bouncing and making audible noise
Post by: Naj ✝︎ on June 03, 2008, 05:20:53

Hello, Mike,

Try putting a squirt or two of oil down the tacho cable from the engine end to see if that stops the buzz.

Also, read this thread while you're in there...

http://index.php?topic=3097

naj

Title: Re: Tach bouncing and making audible noise
Post by: Jonny B on June 03, 2008, 11:06:01

Try the simple thing first. I would also recommend you use a proper cable type of lubricant, graphite based I believe.

Title: Re: Tach bouncing and making audible noise
Post by: grn280SL on June 04, 2008, 22:02:23

Wow, my hands are pretty big so I had a really fun time lubricating the cable and the tach.  Finally got it back together after a rather painful 30 minutes of fumbling with the cable trying to reconnect it to the tach..  started it up.. it's silent and functional.  Hopefully it'll last.