I 'read somewhere' that there is a potential for transmission damage if a 700R4 that is in overdrive with torque converter 'locked' is manually downshifted into 3rd gear. Is this true?

Currently, I use the accelerator to force the downshift as recommended but there are times when I'm caught in (slow) traffic, the trans shifts into overdrive and then I need to accelerate. If going too slow, the engine kind of 'groans' and then the trans kicks down and I'm off to the races :smash:

 

No Damage! My 700 is made to never auto down shift. I always have to do it manually. That way I never have to worry about some surprize downshift in the middle of a corner

 

If you are using the Painless Wiring kit, it's set up to automatically lockup in 4th, but not in 3rd. Therefore, the tranny should be unlocking as soon as you shift.

If, however, you are set up to lockup in 3rd also, there's a potential problem because the TC is staying locked during the shift.

Just my .02 :smash:

 

Page 62 - i have owned different variations of 700R4's I had a full manual with lockup in every gear just by flipping a toggle switch. It's great idea, but they just don't last very long. It's like a clutchless 4 speed.

You are right that most are built for lockup in fourth only and they do unlock during down shift

 

Suppose I should drop a message to Bow-Tie as they provided the harness and trans. Will advise.

 

how was this done ? I hate when mine down shifts from 4th to 3rd, and I even have the parts to make downshifts only happen at 3/4 throttle.

 

I say, install a toggle switch so you can over-ride the 4th gear lockup. That way you can cruise at slower speeds in 4th with out the bog and chugging. I got my O/D set up that way. It only locks when I want it to. I can roll along at 35mph in 4th unlocked. No bog , no chug. Just smoothin right along. I dont lockup unless im doin a steady 50+mph.

 

You can buy the no 4-3 kickdown part. This allows Wide Open Throttle in fourth gear.

I'm not an auto tranny person so I don't know what was modified inside my Art Carr racing tranny to make for no auto down shift. I have to slow down to just creeping along before the tranny will go down to the lower gears.

I also have a lighted 50 amp toggle switch to lockup my three clutch 3500 stall 9.5 inch convertor. I don't hit the lockup until I'm on the freeway. It let's me know when I forget to hit the lockup off because the car starts bucking if you pull up to a stop with the tranny in lockup fourth. It's like driving a stick shift and forgetting to push in the clutch.

 

If you all look in a GM manual, say '87 vette, under 700r4 you will find a whole bunch of variations in how they handle the lockup of the converter....
there are a whole bunch of switches and wiring diagrams...and MY tranny has switches that will allow lockup in ALL gears but first.....so I have the positive lead fed by a brake switch activated relay...so it's allways hot, IF the brakes are at rest...fine...NOW the ground side of the lockup solenoid goes through some switches in the tranny.....which in turn go to EITHER the computer programmed for ~50 mph lockup....OR through a manual switch directly to ground...which means it locks up immediately upon going into 2nd gear, and stays locked thereafter....that means I can have it shift really hard and fast into /outof any gear.....IF I select that option on the console....OR I can have the computer lock it at 50 and be done with it......

NOW for observation and opinion time....I had a 'loose' stock 2k stall corvette converter in the initial build up....and it was like the '87 vette in that it was allways so sloppy in the shifts, the tranny would shift NOW, but there was no pleasing bump...in the computer mode....meaning unlocked unless manually locked by flipping my switch....OK....now in the second repair/build up here with the 2-4 band and the 3/4 clutch pack replaced....and the converter changed to a truck converter...NO slippage..tight....I find pulling the tranny into neutral in traffic stops is just easier, BUT I feel more pleasing bumps in the shifts....and of course less slippage is better for cooling, as the converters generate more heat than the tranny itself....
so now a daze I leave it in the computer mode and seldom in the manual mode.....

frankly I think the shifts are still too soft, I think the driveshaft needs ring like it was dropped on the damn floor when it shifts, no ring, not hard enough...but that's me....

GENE

 

Mines being look at as we post for this. Pops into third way to easy, so they are looking for a broke o-ring or other damage.

 

only corvette 700R4's allow for WOT in 4th (some say 82's didn't have that, mine did...), so if you have a non vette tranny you may need the vette governor. As for downshifting, I always manually ripped through the gears and it never even hesitated.

 

I like the way mine pops from 4th to 3rd. But I really like it when it SLAMS down into second!

Engage warp speed...yeeeeeeeee-haw! :steering: