Hi all. I've been lurking the board for the past couple months and finally decided to "show" myself.

At lunch today, driving home, (yeah, I find excuses to drive my car ) I noticed an odd tranny behaviour. Maybe I'm just oversensitive due to all the dead-n-dying tranny stories posted here ...

Anyway, I'm in D-5 doing the usual 100kph and "sense" that the engine seems to be rev'ing kinda high. The tach says 2200 rpm and I know its usually around 1750 for 100kph. So I slide the shifter into SS to see what gear I'm in (tranny failure paranoia)and it shows 5. Hmm ... odd ... why rev'ing higher today than usual? So I touch the gas, literally just touch it and I "hear"
a shift and my tach drops to 1750!

So it looks like the shift computer "thought" it told the transmission to shift into 5, and displayed that as the gear selected .. but the transmission was still in 4. I'm no mechanic, but that can't be a good thing ...

 

I think this is normal, I have noticed this too. It seems that there are almost 2 stages of the fifth gear. One gives you a little more power and keeps the RPM around 2300 or so, the other one cruises closer to 2000 rpm (all based on going around 70-75mph). My car does this all of the time and I can control it on command with the gas pedal......

 

I do not drive in D5 unless I am driving on the freeway. D4 is perfect for regular driving and the car is alot smoother since it does not want to 'search'

 

I do the same now, but someone told me D4 uses more gas... is that tru?

 

What you are feeling is the torque converter locking up. This will feel like another shift. The converter clutch will engage fully in cruising situations- giving you optimum fuel mileage by reducing rpms. This is a simplified explanation of what happens but it should give you the gist.

 

Wayne:
What about Logic Grade Control ? Could it be a combo of both ?

 

The road is pretty much level, at least where I observed the behaviour and I wasn't accelerating - had reached my cruising speed so I wouldn't expect the Grade Logic to kick in?

Thanx for the info Wayne, it seems to confirm what juniorbean has also observed. I suppose I don't need to order that replacement tranny just yet ...

 

Welcome to the board.

I've also become very sensitive with the transmission. I went to the dealer and test drove another CL and it seems ok. Maybe you could try driving someone else's CL or go to the dealer.