700R4 shifting issues
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Joined: Jul 2010
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700R4 shifting issues
Car was shifting late and hard into all gears (~17 mph 1-2 at no throttle), bounced off the rev limiter for a second before the 1-2 shift at WOT. Outside of that, everything was fine. I adjusted the TV cable last night (found it to be in the unlocked position and fully extended, go figure).
Now the car drives, well, like a car around town. No more jerking around, shifts seem more or less at the right place (~11 mph under no throttle).
Under heavy throttle though, there are issues: At WOT, it just sat at the rev limiter instead of making the 1-2 shift. Couldn't say if it was slipping or not shifting, since I didn't stay on the gas for more than a second or so to try and find out. I got on the gas to ~4000 rpm or so and I don't recall the shift being particularly clean, but only had one chance to do that.
I'm going to triple check the TV cable adjustment and take it out again when I can. Before adjusting the TV cable, it made the WOT shift after a short pause at 5500 rpm. Don't recall it ever having trouble shifting at lower speeds, which it may have last night (4000 rpm).
So, finally, my question: What do you suspect? Governor? TV valve? Burned up clutches?
Now the car drives, well, like a car around town. No more jerking around, shifts seem more or less at the right place (~11 mph under no throttle).
Under heavy throttle though, there are issues: At WOT, it just sat at the rev limiter instead of making the 1-2 shift. Couldn't say if it was slipping or not shifting, since I didn't stay on the gas for more than a second or so to try and find out. I got on the gas to ~4000 rpm or so and I don't recall the shift being particularly clean, but only had one chance to do that.
I'm going to triple check the TV cable adjustment and take it out again when I can. Before adjusting the TV cable, it made the WOT shift after a short pause at 5500 rpm. Don't recall it ever having trouble shifting at lower speeds, which it may have last night (4000 rpm).
So, finally, my question: What do you suspect? Governor? TV valve? Burned up clutches?
Drifting
Joined: Aug 2006
Posts: 1,624
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From: Canandaigua New York
I would pull the tranny dipstick and take a whiff.
Running the tranny with such high pressure, even for a short time is definitely not good for the 3/4 clutch pack.
I had the same issue with my 91 chevy truck. After adjusting the cable, it shifted smooth as could be.. for 1 day.... blew out 3/4 clutch pack going home from work on an uphill climb.
Running the tranny with such high pressure, even for a short time is definitely not good for the 3/4 clutch pack.
I had the same issue with my 91 chevy truck. After adjusting the cable, it shifted smooth as could be.. for 1 day.... blew out 3/4 clutch pack going home from work on an uphill climb.
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Joined: Jul 2010
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I actually changed the fluid four or five days ago, bought the car a few weeks ago. Fluid looked fine, save for a fair amount of fine black residue left on my finger after wiping fluid away (clutch material).
Couldn't say how long it was set like that - at least as long as I've had it (400 miles or so).
Couldn't say how long it was set like that - at least as long as I've had it (400 miles or so).
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The problem you are having if the TV cable is adjusted correctly (tight at WOT) is the band has lost its holding power due to being glazed. TV cable adjustment is critical. It is better to have late firm shifts than early soft shifts as you will take out the 3transmission in a short while. With the pan off, did you see any black residue on the bottom of the pan? Could you take your finger and write your name in it? If you could, it would be a sign of band/clutch material. The 2-4 band on these are in general very good and hold up well especially with the Corvette servo. But as I stated earlier TV cable adjustment is critical to keeping these transmissions alive. Dana
