Tach behavoir during shifts...

Hello:

I recently noticed that when I shift, as I let the clutch out the tach will jump up about 300 RPM's higher than where it will end up, then drop about 300 RPM's below, and then level out. For example, shifting from 2nd to 3rd, engine speed will end up at 3000rpms, when I let the clutch out tach goes up to 3300, down to 2700 then stays at 3000. I just recently put back in a rebuilt trans and new clutch. I did clutch adjustment according to spec. The clutch does not slip, I did the peg it in 4th at 20mph test.

I am not sure if it was like this before and did not notice it, or it is a clutch related problem or not.

Thanks in advance for any help...

Sorry,

car is 79 911SC 107k miles
~ 250 miles on new clutch-PP-TOB,
rebuilt trans...
This happens with no throttle input.
Car runs and shifts smooth...




[This message has been edited by bill mateer (edited 07-07-2000).]

Well, it would have helped a bit if you had told us the year and model of the car, miles accumulated so far ...

Since the clutch, throttle and gear shift are all operated by you, I get a bit nervous about trying to decide whether the tach is misbehaving, or not.

I suggest a very simple test ... drive the car to 30-35 mph and shift into 2nd gear, settle on some constant speed that is comfortable for the engine and continue at that speed for a bit, then remove right foot from throttle, followed one second later by engaging the cluthch. Since NO input is being given to the engine for more revs, the tach should not rise when disengaged!

Let us know if the tach is still acting up during this test ... then maybe you can decide whether you driving habits are/were causing the 'quirk' you are complaining about, or not.

------------------
Warren Hall
1973 911S Targa