700r4 into '70 C10

[BlouDon]

Installed a 700r4 ('93 I think) into my C10.

Fantastic!!

The most complicated aspect about my install was preparing my Carter Thermoquad carb for the TV cable hookup.

I am also waiting for a modern instrument cluster with electronic speedo, tacho and 4 other gauges.

I bought the transmission from local importers for US$375, installed a new cable, filter and sump gasket and it works just fine. Propshaft was shortened, fitted with 700r4 yoke, serviced and balanced. No vibrations.

Next on the agenda is converting from floor shift to collumn shift. The truck was collumn shift manual originally. Clutch pedal is still mounted hidden behind carpet.

[Steeveedee]

Yes, the TV cable adjustment is critical for the transmission's life. Nice choice. I used one (for a Buick hot rod, not my truck) from an '85 car so I didn't have to upgrade to an electronic speedo. Loved that digger first gear!

[BlouDon]

Well, the 700R4 install has now been running quite a bit ... without 12V connected for Convertor lockup.

Did so today:
12v on pin A
GND on pin D

That's it. No in-line vacuum switch. So what happens?

It pulls away in 1st and very quickly locks, in 1st. Thereafter it remains locked for upshifts & downshifts into all gears. Shifts are not harsh at all, but positive.

Downshifts are OK, but engine speed does seem to dip a bit low when coming to standstill. Not a train smash though.

I concluded that either a foot controlled TC engage/disengage switch or a vacuum switch is called for. Best yet would be a speed based engagement. Should not be too difficult to do with an Arduino Uno.

[Smitty]

For technical information on tv cable hook-up/adjustment go to https://www.bowtieoverdrives.com lots of good information on the 700r4 there. Actually bought mine from them 20 years ago. TV cable is extremely important or you'll burn it up.

[AussieinNC]

Originally Posted by BlouDon

Well, the 700R4 install has now been running quite a bit ... without 12V connected for Convertor lockup.

Did so today:
12v on pin A
GND on pin D

That's it. No in-line vacuum switch. So what happens?

It pulls away in 1st and very quickly locks, in 1st. Thereafter it remains locked for upshifts & downshifts into all gears. Shifts are not harsh at all, but positive.

Downshifts are OK, but engine speed does seem to dip a bit low when coming to standstill. Not a train smash though.

I concluded that either a foot controlled TC engage/disengage switch or a vacuum switch is called for. Best yet would be a speed based engagement. Should not be too difficult to do with an Arduino Uno.

There are aftermarket kits available to use brake lamp circuit feed to disengage the lockup, plus vacuum control switches to limit lockup according to vacuum signals...google is your friend...

[jimijam00]

I've got an earlier and built 700R4 with a vette servo in my Chevelle. Does the 93 have the equivalent of the vette servo? If not, get one.

[YoungPup1977]

The best way that I have found to engage the TCC on a 700R4 in our trucks is to use a type 1 VB in the 700r4. This type of VB has a provisioning for the TCC shift valve. This omits any wiring to the transmission. I remove all pressure switches and plug with 1/8 npt plugs. Cut the wires to the TCC solenoid but use the solenoid with a new o-ring with a checkball stuffed into the snout of the solenoid.

No vac switches, no wiring to the 4th gear oil circuits so the TCC engages as soon as 4th gear is achieved which is a PITA in town driving. If you have a really cammed truck, the TCC engages at lower speeds which will lug the motor/truck....

Transtar has a "700-LU" kit that provides the Valve assembly for the TCC. Very easy thing to do, can be used with non aux or aux VB's as well.

Thanks for listening.... I have built hundreds of these and they work !!