Can someone in the greater Pittsburgh area give me the name/ no./e-mail address of someone/ business who can adjust the throttle valve cable on my 76-383 Corvette. It seems to work pretty well and shifts into all four gears. although you sometimes have to get to 2200+rpm before it shifts into 4th gear. Im running a 3:70 rear end. I'd feel more comfortable if someone with more transmission knowledge than me would check it out.

Thanks

 

Is the fluid good/fluid level correct/filter in good shape?

Does the transmission seem to be slightly "slipping" before going into 4th? (Aggressive acceleration will cause a 700R4 to take longer to shift into 4th and "lock up" the torque converter under heavy acceleration if it has lots of miles on the transmission (like mine...212,000 miles)

 

Probably only has less than 1000 miles on it. It really doesn't "chirp" into 4th.

 

Fluid level should be ok,but I bought an aftermarket flex dip stick when installing the crate 383. It was a lot easier to put in rather than the solid tube stick which came with the trans. I will double check the fluid level tomorrow.

 

how exactly did you calibrate that flexible dipstick? you could be low on fluid, do you have an aftermarket pan too?

 

The correct way to adjust a TV cable is with a pressure gauge. I know that I am not specifically answering your question. But you can manually adjust it yourself. by shimming or unshimming the cable length. You first tighten it with shims to the point with someone in the drivers seat with the gas pedal floored that you still get full all four throttle blades to open all the way. Then add about 1/8th to 1/4 less tension. This puts the pressure at mid point and will allow auto shifts off throttle like cruising down the hiway. No tension is harmful So back it off to where it shifts earlier than your 2200

You have to understand that the governor springs and weights sets the WOT max shift points. The TV cable determines the of throttle shift points in conjunction with how the valve body was setup.


My advice is read up on TV cable adjustment and get an understanding of the relationships. I hope I was some help.

 

If I remember I installed the dipstick tube and dip stick while I had the trans. pan off and marked the stick where it protruded into the pan and level with base of the trans. case. This assumes the fluid would be to the top of the pan when full.

 

You would rather have the TV cable too tight as it is now rather than too loose but try a few clicks looser and se if it corrects the problem.

 

And the geometry between WOT and no throttle I've been told is critical... There is a 'sweet' spot on the linkage, away from the pivot point, that will achieve this...

Mine was set by my trans guy who built and installed the 700r4... But he was saying I may have to buy a new throttle linkage bracket if mine could not get the proper arc... Thankfully, what I had worked fine...

And a 'improperly ' adjusted cable on these transmissions can hurt the trans in a matter of miles if not minutes, not hundreds or thousands of miles... Wish I had more info...

Another thing I was told, is that these transmissions have a weak spot for shifting from nuetral/park into gear... Try to keep your Rpms as low as possible when doing this... If the motor Rpms are too high, it'll shear a (spur) gear that engages the trans and cause you to lose 2nd, 3rd , 4th and reverse... Something like that... Trans guy said it'll leave you with first to limp it home, and then it'll take extensive work to repair.. So I'm always very cautious to get the motor warned up and at a smooth low idle before I attempt to move the car...

With my 2.73 rear end, it takes me until 63-67mph before hydraulic lockup will engage in 4 th... He also added lockup in 3rd... No moving parts reduces friction, wear, and heat ... Here's a slow vid showing my shift points at low throttle...