700r4 fiddly bits
On mine, i used the factory lever and original detent plate and all lines up, just had to grind the detent plate to get first. The 2004r I installed in a friends 78, I used the shiftworks kit and it works well also when all the parts are installed.
My 75 will be getting a B&M Hammer shifter this spring.
Last edited by '75; Mar 10, 2015 at 07:48 PM.





looked for a solid state relay, cheapest i could find do do the job was 50$, bit expensive for a quick fix.....
turns out they only switch AC or DC, not both like a normal relay which can do either, guess which ones are the dear units....

started the exhaust mods last night, got the easy side done.
Last edited by riverracer au; Mar 11, 2015 at 07:01 PM.





"hi , i purchased a B&M controller with the parts i got from you.
have connected it up, got red light, spun up with a drill, turned **** until green light, but only getting 8.2 volts out.
is that enough to activate the soleniod?
or is there a problem with the unit?
thanks alan"
got a reply from BTO
"Eight volts is plenty for the lock up solenoid. I have installed these in 6 volt cars without any problems.
I once did a Packard that would only muster about 4.5 volts and it worked.
Thank You, Rich Weller, Bowtie Overdrives"
that's good news, and one less thing to worry about.
didn't have to move the bracket, plenty of clearance on the park brake cable, bout 5/16" clearance.
little close on the passengers side, bout 1/8", but it's only the insulation foil, will remove a small patch if it rubs..
i already have slip joints in my 2" exhaust pipes just after the x-member.
drivers side, just cut 3" off one end, slid back into rear main pipe and added a bit back in, had lots of room.
passengers side a bit more complicated, i bought a couple of scrap bends, bit of cut n shut and fits well.
excuse the welds, still need to be cleaned up, my brother tig'd with stainless wire.
i can drop the pan very easily with no interference on the exhaust.
just working out making hangers to support where it goes thru the x-member.
have changed the speedo drive gear to a "19 tooth" to run on the existing driven "43" that came with the box.
only ordered it last fri arvo here, and it arrived thurs morn here, great service from BTO.
Last edited by riverracer au; Mar 12, 2015 at 08:18 AM.
i'm using 235/60R15 tyres (26.1 tall) 3.08 rear in the t700 box
i have looked at 3 "speedo calculators" and i get different answers with each.
i want to order the other parts from BTO soon, and thought i'd get the gears as well





as i used the tail housing mount, i used the std mount position for the hanger
it's alive... the new trans is a go'er
the 1-2 shift is a bit harsh
and it chirps the tires easy if i boot it around a corner 
at a 100kph (60mph), i used to do 2500rpm, today i was turning 1850 revs, not a bad drop with OD
thought there was something wrong with my lockup, got home and it turns out i left a wire off the brake switch

will have to take it for another test morrow.. and see if it drops another 2-300 with the lockup.
should save a drop of fuel or 2 lowering the rpm that much
The Best of Corvette for Corvette Enthusiasts





Gear ratio calculator
http://tri-5.chevyrides.com/rpm.php
enter the info, then just swap between the t400 (or whatever you have) and the 700r4/200-4r to estimate the drop.
then add a bit more for the lockup






i removed the vac switch out of the equation, using B&M controller - brake switch - soleniod
set controller to switch on at bout 90kph, but i think the 8v output is not enough, even after what BTO said.
will try temporary setup with direct 12v wired thru a switch.
i pulling approx 15hg on the vacuum gauge at between 90-110kmh(56-68mph) steady flat road speed
so i set the switch to open at approx 10-12hg when accelerator pedal is depressed

i removed the vac switch out of the equation, using B&M controller - brake switch - soleniod
set controller to switch on at bout 90kph, but i think the 8v output is not enough, even after what BTO said.
will try temporary setup with direct 12v wired thru a switch.
i pulling approx 15hg on the vacuum gauge at between 90-110kmh(56-68mph) steady flat road speed
so i set the switch to open at approx 10-12hg when accelerator pedal is depressed
Then.......for now just use an ON/OFF switch to send a full 12-13 volts straight to the solenoid (no controller or safety switches) to make sure it engages/disengages....JUST DO NOT FLOOR THE GAS PEDAL AND DESTROY YOUR TRANSMISSION WITH THE SOLENOID ENGAGED.
At 60 mph engage the On/OFF switch to ON for 30 seconds to make sure the solenoid stays engaged and notice the rpm DROP......
Then turn the On/OFF switch to OFF for 30 seconds and notice the rpm INCREASE.
________________________________________ ________________________________________ ___________________________________
It IS possible that the solenoid was somehow constantly engaged previously.....that's the first thing I though of when you stated how much of an rpm drop you noticed on the test drive.
Is it possible that you had the vacuum switch wired "backwards"?
Is it possible the brake switch was working "backwards"?
Just add one safety device (B&M controller for example) at a time...then test drive the car before adding another device (brake switch) or (vacuum switch).
The B&M controller may be all that is needed. (I don't use a controller, so I need a vacuum switch, brake switch, and an ON/OFF switch)
Last edited by doorgunner; Mar 15, 2015 at 03:52 AM.





i ran a switched 12v source thru brake switch to the plug on the side and tried again, still no change
when activated, should it be instantly noticeable?
i suppose it could be either the solenoid or the 4th gear pressure switch in the trans.
guess i'll be dropping the pan and having another look during the week.
Last edited by riverracer au; Mar 15, 2015 at 04:49 AM.





speedo didn't work on the first try, the cable wasn't engaged in the drive housing properly,
seams that there is some freeplay back n forth in the outer sleeve,
when i screwed the B&M pulse generator on with the short cable, it allowed the inner to move away fron the drive square in the gear.
placed a small piece of plastic tube over cable to stop the cable sliding forwards and going anywhere.
now if the lock-up was that easy to fix, i'd be a happy chappy
i ran a switched 12v source thru brake switch to the plug on the side and tried again, still no change
when activated, should it be instantly noticeable?
i suppose it could be either the solenoid or the 4th gear pressure switch in the trans.
guess i'll be dropping the pan and having another look during the week.
Make sure the solenoid has the ground wire connected to the internal body of the transmission OR make sure it is wired to the case connector and THAT harness is properly grounded to the frame at some point.
I had to remove my 4th gear pressure switch/attatch an ohm meter to the two contacts/apply over 100 lbs. of compressed air to the fluid port on the switch to make sure it was a NORMALLY OPEN switch that was working correctly----it was defective---so I bought a new NORMALLY OPEN switch/installed it/test drove the car/turned on the Overdrive switch....lock-up and rpm drops was instant!
Then a week later the lock-up quick working again....this time the AutoZone lock-up solenoid was fried/defective.....I installed a new solenoid and everything worked correctly/400 rpm drop when I switch the Overdrive ON.
Then I added the vacuum/electric switch to the wiring so I wouldn't have to turn the Overdrive switch OFF every time I decided to accelerate heavily.....the vacuum swithc worked great with minor adjustment.
It's just a matter of doublechecking to get the overdrive working correctly.





now when i switch on 12v the lockup works.
obviously it now works in 2,3 and 4.
is that a problem having it on/using it in the lower gears?
i re-connected the NO vac switch, and that drops it out under acceleration, set @ <11hg
i assumed that the factory installed 4th gear pressure switch was a NO, is that correct?
maybe that's kaput.....
more to come
Last edited by riverracer au; Mar 18, 2015 at 05:54 AM.





had a vacuum gauge on dash connected to the same port as the vac switch,
holds above 15hg driving around, press the throttle it drops below 8hg, so set switch with mityvac at about 11hg.
problem was it hunted on n off as the vacuum stabilised with the extra 200rpm drop, what to do??
then i thought, i have a adjustable timer relay in my electrical junk,
so added the timer relay as the last control before the trans,
switch 12v on ( yes )
vac switch above 15hg ( yes - no ) drop below 11hg
brake off ( yes - no ) brake on
wait about 5-10 sec ( yes )
12v out to trans ( yes )
now to get the B&M speed controller's 8v output to switch the solenoid.
forgot to re-connect it and try it on the solenoid now i got the above to work

tried making a simple voltage regulator to convert the 8v to 5v to switch a 5v relay to switch 12v supply
nothing like a 'rube goldberg' way to control the lockup, but will be fully 'automatic" when done...
Last edited by riverracer au; Mar 18, 2015 at 07:14 AM.
With the lock-up tirned OFF....does the transmission shift into 4the gear at cruising speds above 45 mph?
With the lock-up switch turned ON... it should go to 4th gear and then to 4th gear lock-up at cruising speed if the pressure switch is good4th gear pressure switch is defective if it doesn't lock up in 4th and the rpm doesn't drop when cruising.
Make sure you have all the above working correctly before installing the B&M stuff.





trying to get the shift points correct as 1-2 is a bit hash and late.
spoke to the re-builder that did the trans, and he's going to have a look next week.
so if he has to drop the pan to get to the 1-2 accumulator, i'll get him to check the 4th gear pressure switch at the same time.
just need to modify the cable bracket, needs a little more cable adjustment.
the vacuum switch works very well, cruise along with lockup and just have to lightly press and it disengages.
then once back to cruise speed, timer allows vacuum to settle for about 10sec, then lockup comes back on.
and the B&M controller WILL switch the solenoid with only 8volts, well it did with mine.










