700R4 still confused..3rd or 4th lock-up

Imo Apita

Well-known member
Joined
Feb 28, 2009
Messages
244
Been looking into a possible 700R4 swap.
Am aware of the cross member mod and the drive shaft shortening required.
Although I read somewhere (can't remember where) that certain versions of the 700R4 have a shorter tail shaft which means no drive shaft mods required, true/false?

Main question:
Still confused about the 3rd gear and 4th gear lock-up.
Why would you want to disable 3rd lock up in favor of only 4th lock up?
I've been told of special mods that disable down shift in 4th to prevent over-revving when you go full throttle in 4th.
However, my shop buddy tells me it's not necessary since a 700R4 will NOT downshift anymore above 75 mph.
So from moderately confused I'm now royally confused.
 
The governor springs and the cable setting can be adjusted to eliminate annoying kick downs. The tranny can also be set up to hydraulically lock up the converter. Mine has ZERO wiring to it.
 
They will definitely downshift over 75 mph! mine did it over the weekend @ 85-90 mph. Art
 
Some cars were setup from the factory to lockup in 3rd and 4th. More hassle IMHO. In addition to the 3rd gear and 4th gear switches on the valve body, there is a 3-4 pulse switch too. Final effect is the TCC is locked in 3rd, unlocks, shifts to 4th and locks up again. Too much monkey motion. And 3rd is 1:1, it generates very little excess heat, so the TCC lockup is a fuel economy move. It really needs the TCC lock in 4th- the OD runs the planetary set and makes heat.

For ease of installation, the hydraulic only lockup seems like the way to go.
 
Some cars were setup from the factory to lockup in 3rd and 4th. More hassle IMHO. In addition to the 3rd gear and 4th gear switches on the valve body, there is a 3-4 pulse switch too. Final effect is the TCC is locked in 3rd, unlocks, shifts to 4th and locks up again. Too much monkey motion. And 3rd is 1:1, it generates very little excess heat, so the TCC lockup is a fuel economy move. It really needs the TCC lock in 4th- the OD runs the planetary set and makes heat.

For ease of installation, the hydraulic only lockup seems like the way to go.

Can I modify my 700 in the Clamper to hydraulic lockup in 4th only?? like described above....and HOW???

much simpler than all this wiring crap I"m dealing with now, and that solenoid that is apparently hanging...

:shocking::beer:
 
Some cars were setup from the factory to lockup in 3rd and 4th. More hassle IMHO. In addition to the 3rd gear and 4th gear switches on the valve body, there is a 3-4 pulse switch too. Final effect is the TCC is locked in 3rd, unlocks, shifts to 4th and locks up again. Too much monkey motion. And 3rd is 1:1, it generates very little excess heat, so the TCC lockup is a fuel economy move. It really needs the TCC lock in 4th- the OD runs the planetary set and makes heat.

For ease of installation, the hydraulic only lockup seems like the way to go.

Can I modify my 700 in the Clamper to hydraulic lockup in 4th only?? like described above....and HOW???

much simpler than all this wiring crap I"m dealing with now, and that solenoid that is apparently hanging...

:shocking::beer:

YEP. I think it's Trans-Go that has the stuff to do it.
 
Thanks guys....

The governor springs and the cable setting can be adjusted to eliminate annoying kick downs. The tranny can also be set up to hydraulically lock up the converter. Mine has ZERO wiring to it.

Which kit was used to make that happen?
So if I understand correctly I can get rid of 3rd lock up in favor of 4th? :clap:
 
Thanks guys....

The governor springs and the cable setting can be adjusted to eliminate annoying kick downs. The tranny can also be set up to hydraulically lock up the converter. Mine has ZERO wiring to it.

Which kit was used to make that happen?
So if I understand correctly I can get rid of 3rd lock up in favor of 4th? :clap:

I called TGo and they said it has to be the 82-86? valve body on the tranny....can not be done with the later VB.....

:quote:
 
Thanks guys....

The governor springs and the cable setting can be adjusted to eliminate annoying kick downs. The tranny can also be set up to hydraulically lock up the converter. Mine has ZERO wiring to it.

Which kit was used to make that happen?
So if I understand correctly I can get rid of 3rd lock up in favor of 4th? :clap:

The lock up was a kit. Transgo I think.
Shift points were trial and error. My friend owns a tranny shop, and we changed gov. springs about 3 times untill I was happy with my custom shift points.
I also added a tranny cooler, as spirited drivingng in the mountains in lower gears without it locked up created MUCHO heat. Not an issue now.
I am quite happy with the performance and the milage.
I have had it serviced since new at 10,000 miles. No issues at all.
 
Thanks guys....

The governor springs and the cable setting can be adjusted to eliminate annoying kick downs. The tranny can also be set up to hydraulically lock up the converter. Mine has ZERO wiring to it.

Which kit was used to make that happen?
So if I understand correctly I can get rid of 3rd lock up in favor of 4th? :clap:

The lock up was a kit. Transgo I think.
Shift points were trial and error. My friend owns a tranny shop, and we changed gov. springs about 3 times untill I was happy with my custom shift points.
I also added a tranny cooler, as spirited drivingng in the mountains in lower gears without it locked up created MUCHO heat. Not an issue now.
I am quite happy with the performance and the milage.
I have had it serviced since new at 10,000 miles. No issues at all.

Have a pix or description of that cooler man??

all I have is a ten row 1/2" pipe cooler on the Clamper...I wonder if it's enough...seems fine around the hood for 30 minits, but I wonder...
 
Have a pix or description of that cooler man??

all I have is a ten row 1/2" pipe cooler on the Clamper...I wonder if it's enough...seems fine around the hood for 30 minits, but I wonder...

34939cdb4ec56f.jpg
Noonie gave me the number. Not too spendy, and fits between the hood opened, and the brace below. Something like 6"x22" I believe. Had to heliarc some tabs on, then tek screwed into the condenser frame.
 
Unless GM did something I've not seen (very possible) all the 700's were 100% electric control thru pressure switches on the lockup. Wire it so it bypasses the 3rd pressure switch and has to see 4th. You can also add another pressure switch that sees governor pressure so it'll go into 4th and not lock instantly. THey still have the ports in the valve body for the switches, or you can put switches in the pressure taps on the outside of the case.. If you're into twinkly lights put one in all the external ports, and make the pretty lights blink when it changes gear.

The hydraulic thing in Bird's car works great.

In the real world, you need to be using a trans from 88-92 anyway- New and improved stuff inside.
 
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