Yeah, I know - I can find it in the dictionary between S*** and Syphilis.

I've had my '89 convertible for a dozen years and I've yet to get used to the idiosyncrasies of its automatic transmission. Having never driven another C4 with auto, I don't know if this one has been modified, but I can't imagine Chevy selling a car with this poor of a slushbox. It won't shift unless you let up on the gas pedal. If you hold the pedal down from a dead stop, it will stay in low forever.

Downshifts are sudden and solid enough to crack walnuts between your teeth. Either on deceleration or when shifting into "passing" gear.

I dearly wish this beast had a six speed. I know it's not economically feasible to change it over and it would be much better to sell it and buy a manual trans car. It's just that if I went to the trouble to sell it, I'd likely buy a different toy instead of another C4.

Just venting. Anybody got a clean '89-96 six speed convertible that wants to trade? Hmm. Didn't think so.

My last Corvette had a much smoother auto tranny.

 

Im not being jerky ,but has the trans ever been serviced? Maybe its time

 

Sounds like the tv cable is out of adustment also

 

Not since I've owned it. The odometer read around 43,000 when I got it and has about 20,000 more since then - I haven't driven it much.

When I bought the car, I had all the fluids changed IIRC, but I'm not sure if the tranny fluid was actually changed or filters taken care of. I didn't stand there and watch. It was done by a trusted mechanic (if there can be such an animal). I remember him telling me he had to straighten the X-brace to get it off & back on again.

Getting it serviced by an expert might be a good option. I just remember the beautiful whine of 1957-1960's Chevy manual transmissions. Do the six-speeds still do that?

 

TV cable? Throttle Valve??? I'd have to toddle out to the shop to look it up in the manual.

 

I have a 96' LT-1 with auto trans and just the other day a friend who never rode in a corvette ask me to take him for a spin. He made the comment that he has never been in a car that shifted so smoothly and seamlessly while under WOT. I have the 3.07 rear and have been in quite a few vets and these C4's do have one of the best automatics I've ever driven. Mine shifts so quickly that you don't even know it happened. Someone must have modified yours or it must need servicing really bad. Get it checked. The C4 auto trans is one of the redeeming qualities of this series and yours needs something to bring it back to its original quality. The TV is a mechanical cable that lets the transmission know what the engine is doing.

 

Check the TV cable adjustment.

 

i belive the tv cables main job is more just to downshift the transmission when you mash the accelerator hence its slang name of kickdown cable, i would be more looking in the area of the governor.

i have seen these that the plastic gear apple cores and really messes with shifts, also they do sell kits to reprogram/recalibration kits for these governors .

located taward the tailshaft area and usually have a thick spring steel wire overtop of it thats not shown here.

governor shown with a recalibration kit

hope this helps

 

YEP TV Cable a whole 5 minutes to fix. There are plenty of write ups, been so long, you pull the throttle body all the way forward, to the left of the spring housing there is a plastic small square, push that in and let the cable go, then with your hand, open the throttle cable again. That adjusts it, but be best to find a write up. It will cause exactly what the OP says, its not just for downshifts

 

sorry your correct its not just for downshifts, its to raise tranny line pressure, shift,points, shift feel, part throttle downshifts, and detent (full throttle) downshifts pressure as well and can cause permanent damage if not hooked up or adjusted properly. so check and adjust that first as its simple then check modulator if prob still there or if you want to taylor shifts a bit more.

Adjustment procedure (self-adjusting cable)

1. Stop the engine.
2. Depress the adjusting tab and move the slider back through the fitting away from the carburetor until it stops.
3. Release the adjustment tab.
4. Move the throttle linkage to rest against the full throttle stop, then release it .
5. Check the cable to insure that it is not sticking or binding.
6. Road test the vehicle.
7. If the problem still exists, refer to the cable diagnosis section.


-------------------------------------------------------
or
Adjustment of the TV Cable on a gasoline engine.
a. Adjustments are made with the engine off. Locate the Adjust Tab on the cable housing. Press in the tab and push the slider as shown in Figure 3.
b. Release the tab and rotate the throttle lever to WOT and the cable will self adjust itself as evidenced by a few audible clicks. Release the throttle lever and check the cable for any signs of binding or sticking.
c. Road test the vehicle. Under moderate acceleration your shift points should be close to the following:
1-2…………………15-20 MPH
2-3…………………25-30 MPH
3-4…………………40-45 MPH


whichever is easiest for you to understand

 

Wow! I didn't realize there were those adjustments which could affect the shifting. When I first got the car, my mech told me it had been set up for Autocross with a transmission "kit" and heavier shocks.

I will look into the transmission thing and perhaps it can be smoothed out. If a kit has been installed, maybe it can be un-installed. I don't autocross the car at all.

I have a '92 GMC Sonoma 4x4 with an automatic. I love it! It shifts so smoothly as to be almost unnoticeable. It would be great if the 'Vette was anywhere as nice. Thanks for the advice.

 

I'm not sure why you guys think a smooth shift is a good shift. One poster said that at wot, he couldn't even feel the shift. That is really not what you want. At wot or with any of my cars on the street, I want to feel the shift. The car runs quicker and the tranny lasts longer. I'm not talking about leaving rubber at every 1-2 and 2-3 shift, but a good solid shift.

 

i'm with you on that, fully agree with both the longivity and the feel.
i prefer to have a nice positive firm shift durring normal driving and firm enough that when im really on it should get tire bark at least durring 2-3 shift.
but ya to each there own i guess

 

Don't forget that a '96 has a 4L60E. The electronic versions of these transmissions can do magic that a 700r4 can't even come close to matching.

 

... If the trans has a shift kit in it , the line pressures will likely be higher than stock ... line pressure feeds directly to the governor and WILL affect the timing of shifts , especially at WOT ....... refer to the post regarding the governor re-programming kit and get ready to do some sit-ups ... good for the 'ol spare tire ..........

 

At 71, I'm not likely to ever be at WOT. The ol' ticker doesn't respond well to instantaneous changes of direction. I've driven enough really fast cars on tracks to last me. I just be stylin' from here on out.

If there's adjustments to be made, I'll make them. If there's a shift kit in there, it can be removed. When it's as smooth as my truck, I'll be a happy man.

 

If you would join the group of Corvette owners that get together semi regularly, arranged on the Northwest regional forum, we could check out your car and even help with making adjustments.
Just happened. July 20, Corvette Show at Lee Johnson in Kirkland and All Corvette and Camaro Show in Tacoma.
Coming up.
Aug. 8 and 9. 500 Corvettes gathering in Puyallup and cruise to Lemay Museum for the 60 Years of Corvettes exhibit, featuring the original Sting Ray, Manta Ray and Mako Shark cars.
August 17 Drive out on the Olympic Peninsula.
August 24. Gathering at the Hydroplane Museum in Kent.

 

I put my name in for the 8/17 event. You guys will be driving right past our home near Hwy 302 and I'm hoping to join in at that point.

We used to do a lot more stuff like that, but not so much lately.




2002 Vashon Is.


2002 Pacific Grove Rally


2002 Pacific Grove Rally


2001


2001

I'll be looking for more info on the Olympic Peninsula drive and hope to get someone to give us a call when you cross the Narrows. We'll be waiting about five miles after you cross the Purdy bridge on 302.

 

Kudo's to Ladystoy69 on the TV cable post. Hopefully the OP will make this simple adjustment. I've been told a misadjusted TV can cause damage. Don't know if it's true or not. An automatic trans is something I've always let others do, but I hear they're simple.

 

I copied the whole procedure(s) to a document and printed it out. I'll have it in hand while I give it a try.