Driving my 82 collector down the interstate yesterday. On my way home after taking off from a stop light it took for ever for 1st gear to kick in. Seemed like it was in a strain to do so. Has never done this. You know how a manuel shift is when you wait longer to shift it. That kind of sound and maybe rougher. Any ideas. Thanks

Automatic I presume?  Have you checked the fluid lately?  Is it full; does it smell burnt or look burnt?  Been changed recently?

The description is a little hard to unnerstand, for me. "Taking off from a stop light it took for ever for 1st gear to kick in"is confusing. When taking off, it should be in 1st gear already. Are you saying it is NOT in 1st when you stop?
Or....do you mean it takes a long time for it to shift into 2nd after taking off from a stop?
Does it shift into 3rd and 4th ok after that, or is there a problem with those shifts also?
You could simply have a TV cable that went out of adjustment, or you may have a stuck valve in the trans valve body, or....it could be something even more sinister.
A little more info will help with the diagnosis...

From what I recall your '74 would have a vacuum modulator to regulate shifts, not a TV cable.  (at least my '76 TH350 had a vacuum modulator)The vacuum hose / line could have slipped off, mimicking WOT and delaying the shifts....  Or the vacuum modulator diaphragm gave up, should be able to test to see if it holds vacuum.

 

sorry for the confusion, I meant from 1st to 2nd.  the fluid is fine. could be a vacuum, cable or whatever problem. no burnt fluid smell either. thanks

My '69's automatic transmission suddenly had the same shifting symptoms and an inspection of vacuum line where it connects to the modulator found a deteriorated line. Cheapest "fix" I've ever had on this car....replaced the hose and shifting returned to normal.....Hope yours turns out to be that easy. Just before this happened, I had noticed gray smoke coming out of the tail pipes which turned out to be a symptom of transmission fluid being sucked up in to the engine from a bad vacuum line hose. After the line was fixed, the gray smoke stopped. 

Hope its that simple too! thanks

By the way, my Vette is an 82. Will everything be the same?

No....the '82 used the 700R4 transmission, which is a 4 speed automatic. No vacuum modulator here. The shift feel/pressures are controlled by the TV(throttle valve) cable, which is attached to one of the throttle bodies on the intake. The cable comes up from the trans to the rear of the intake.



Check the actual metal cable part where it comes out of the plastic sheathing for any fraying, or other damage that would keep the inner cable from sliding in/out smoothly. The adjustment is by pushing IN on the small metal tab on the cable end(arrow), then moving the cable in/out of the adjustment block. Moving the cable towards the front of the car will make the shifts earlier and softer, moving the cable towards the rear of the car makes the shifts later and firmer. You do NOT want the shifts too early, or soft.....trans damage WILL occur if it shifts too soft.

The cable is responsible for controlling the fluid pressure of the trans mainly. It also has an effect on shift timing. However, it is the trans governor that is most responsible for shift timing.



The governor is basically a mechanical speed sensor that tells the trans how fast the vehicle is moving, and what gear it needs to be in. A failing gov can cause all kinds of shifting issues, from wrong gear starts, late/early shifts, to no shift at all.

The last thing that can cause a weird shift pattern would be the valve body itself. Valve body problems with the 700 are not very common, other than a sticky/stuck TV valve.....which brings us back to the TV cable itself. Check that cable first, and go from there. Make sure it is not damaged, and that you can pull it all the way out, and it pulls itself back in. ANY binding of the cable can cause shifting problems.....gotta make sure the cable is working well first.

I don't recommend making any adjustments on the TV cable at this point....just check to see if it is free to work properly.