Weird speedo/tach problem...
Thread Starter
Pro
Joined: Sep 2004
Posts: 690
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From: Madison WI
Weird speedo/tach problem...
Okay, so my speedometer and tach have been acting rather weirdly lately...basically, they work fine at first (well, the speedo reads about 2mph low and I don't know the accuracy of the tach but I don't have any reason to doubt it), but once the engine gets hot, they will start to bounce, the tach just a little bit but the speedometer will bounce a lot. I've noticed that it only happens consistently on hot days, but when I first fire up the car in the morning they're fine - it's not until I've been driving for a little while on a hot day that they start bouncing. What's going on? I know I must have some problem with my speedometer gear, because when I roll to a stop it'll read, say, 5mph but then suddenly bounce very high at regular intervals. Still, the problem goes away if I'm actually driving, until it gets rather hot. Any suggestions?
Burning Brakes
Joined: Jun 2005
Posts: 764
Likes: 2
From: THE OLDER I GET THE BETTER I WAS! NORTHERN ONTARIO
Speedo cable needs lubrication for sure....the tach could be loose at the distributor...when the wire heats up from the engine temp it could start to move around a bit possibly causing the tach to be inaccurate.good luck
Thread Starter
Pro
Joined: Sep 2004
Posts: 690
Likes: 0
From: Madison WI
Originally Posted by G dad
Speedo cable needs lubrication for sure....the tach could be loose at the distributor...when the wire heats up from the engine temp it could start to move around a bit possibly causing the tach to be inaccurate.good luck
Burning Brakes
Joined: Jun 2005
Posts: 764
Likes: 2
From: THE OLDER I GET THE BETTER I WAS! NORTHERN ONTARIO
Speedo Cable comes in two parts with cruise as on my 79 you should be able to take it apart the the transducer or at the joint & if adventureous remove the springwire... soak it with tranny fluid & pop it back in...or just spray a little LPS or WD 40 type lubricant into the cable housing & presto re-assemble. Have Fun.
