200-4r lockup issue
I had thought that using the stock vacuum switch to provide the +12v to lockup solenoid in tranny would work, but I don't think that the stock switch is in range of my modified motors vacuum range for it to work properly.
http://i244.photobucket.com/albums/g...osedWiring.jpg
I am thinking I might need a "non-stock" vacuum switch, that is adjustable, if there is such a thing ........ anyone heard of one that would work? I will take some manifold vacuum data readings during a road test in next few days to see exactly what I need, range-wise.
Has anyone else already "invented the wheel" here and have a good solution? I am all ears
http://www.transmissionhead.com/#Parts
With cruise..... Two contacts "two Connections"
The lockup can be wired with either combination
also, I am wondering what the "delay" filter that sits right before vacuum connection on switch, has some effect on my 200-4r setup

Surely some of you SMART ONES out there has gotten your 200-4r to work correctly

Tomorrow, I am going to check my vacuum switch AND hook up a vacuum gauge so I can drive it and see where my vacuum readings are exactly, so I can get myself a "workable" switch!
But that is just me ......
The Best of Corvette for Corvette Enthusiasts
just wire the +12 to the tranny, through a relay that opens contacts when the brake lights lite......Rat Shack....or parts house....the ground side is usually perma wired inside the tranny to a MINIMUM of a 4th gear switch on the valve body, 4th and closed, so lockup occurs....
then another wire can be run out off that 4th gear switch, to allow control by computer grounding at speed, OR a dash switch like I have to ground it directly for really nasty shifts all the time....
a Vacuum switch is totally not needed and a poor idea anyway....for driveability reasons....
The TCC is really loose (want to get a tighter one) and see how it performs ......
PS - 1) would it make any difference IF the GROUND wire from 4th gear NO switch is just spliced into the solenoid ground wire (from console switch???) I wouldn't think so, but thought I would ask .....
2) Is the logic that when in 4th and cruising with TCC locked up, and all of a sudden you give it some throttle, to say, pass another car, that it will downshift to 3rd and unlock, or some other line of thinking ???? I ask because of what if you don't give enough throttle to downshift, and I think there is the twitch in my thinking, that the TCC stays locked up, where you would like it to slip. So then manifold vacuum would be a good indicator of where motor is at, and could unlock TCC. That is just my thinking and I could be WAY OFF
Last edited by tomard; Sep 22, 2008 at 08:36 AM.
[/QUOTE]You are thinking correct. That is the purpose of the vacuum switch. To drop out of lockup and down into third
What 4th gear switch are you using?
Single terminal
Double terminal
Last edited by Artsvette73; Sep 22, 2008 at 02:13 PM.
My stock switch is set to Close at 7in/hg and provide 12v at that point, and open at 2.5in/hg (removes the 12v)......seems like a world away, when you look at my readings that I got off road test just completed !!!!! (MPH is little off, as I have to zero in on speedo gear one less tooth)
Gear RPM MPH VAC in/hg
OD/P 900 0 14
4th 2000 60 17 Cruise
4th 2500 70 15 Given light throttle/to "pass"
Adjustable switch, in my immediate future ?????
Vac drops when you goose the gas, so a set point of 14 or 15 should let it unlock
so that leaves the lockups to be controlled via the ground side of the lockup solenoid....which BTW I hope is NEW in your rebuild, and fresh white nylon, not some damn brown heated looking thing, and don't ask how I know this, as when building MY tranny I did not change it, and so had a hard time locking or worse yet, UNlocking the converter, and I had that herkey jerkey crap operation wether upshifting or downshifting in traffic.....put the tranny in 3rd gear via the lever, and IF you don't have a 2-3 gear lockup switch OR a computer telling it to lockup you can ground and unground that wire to the ground side of the coil...thereby locking and unlocking the solenoid....
I could tell by feel of the car that it was a problem, and when NAPA had a solenoid in stock down the street, I KNEW IT.....they don't stock dead parts not turning off the shelf....duh.....
so now to the situation with your cars.....It can vary with the internals and how many switches you have but you always have a 4th gear switch that locks the converter regardless of any computer or other input on that end of things....
so that leaves 2-3 gear lockup, first won't ever lockup as that line is hydraulically controlled by stopping flow to the valve in the first place while in 1st gear.....so grounding the point/solenoid on 2-3 will lock the converter as if it was in 4th....you want a nice slam shift .....ground it all the time, kinda hard on the clutches I understand, maybe even the converter too.......I have a switch on my console that can select wether the tranny locks in 2-3-4 solid without any unlock between shifts....as in slam gears HARD, OR the other position I have it in is the computer locking it at about 40 mph....which typically is in 3rd gear in normal driving, sometimes 4th along with the pressure sw on the valve body....
I can not recall EVER feeling the tranny in 4th and unlocked....
now with my first auto tranny in this car, it was a 700, same deal but the 700 always downshifted at speed and going WOT, a pesky bug I dearly loved to hate.....
this 200 4r has a Trans Go shift kit in it, the big one....and so it's manners are ever so much better, I can go WOT at say 80 mph and the tranny sticks in there.....Locked.....which is what I want....none of that wishey washey crap....




















