700R4 dilemna

Joel,

I understand the valve installation may prevent downshifts when I want them, like from 30 -40 MPH at part throttle. It doesn't drop all the way to second unless I shower down on it under 40 MPH. I'm talking about running 90 - 100 MPH in 4th then trying for a top end run. I don't need a downshift there.

Do you know anyone with experience in the new valve. I had looked into the valve some time ago but forgot the source. I have been waiting to get 'lectric to my new garage so I could operate my lift.

Dave

Dave, check this out... I use these all the time.

                                       Click for link


btw...this is the same set-up GM installed in the later Corvette 700s('87>), to solve the same problem.Adams' Apple2007-11-04 15:10:54

I'm having a similar problem with my 700R4. Mine has a kit that control everything hydraulically, so no electrical connections. I can't figure out how to get the TV cable adjusted so it will lock up the torque converter.

If the trans is set-up for a hydraulic LU, it will ONLY go into LU at a specific road speed(mph)...the TV cable adjustment will have no effect on it.
In your case, you may need to have the spring changed in the LU valve to a lighter one, so it will lock-up earlier. The kits for this normally come with at least three different springs, so the LU apply can be tailored to work at different speeds.
You should be able to feel when it goes into lu, just after the shift into 4th(around 45mph). Depending on what spring tension was used, it may not lock-up until later. There is also a check-ball that must be installed into the snout of the lu solenoid for this to work. If the ball was not installed, the trans will never go into lu.
One way to determine if the lu is working, is to watch the tach. After the shift to 4th, you should be able to see the tach drop down a couple hundred RPM once the converter does go into lu. Once the converter locks up, applying small amounts of throttle should not raise/jump the rpms. If there is no lu, the rpms will raise considerably with just slight throttle.

That being said, there are some folks that will install the ball in the lu solenoid, without using the correct lu valve line-up. This creates lu from 2nd gear up, regardless of throttle, or road speed. It also makes the shifts a little "lunge-y", or rubbery. There are some valve bodies, the late '86 and ups, that do not have a place for the lu valves. These vbs are strictly computer controlled, as far as lu. These should not be used for this application, for this reason.

                                                        More info on lu valveAdams' Apple2007-11-04 15:09:54

[QUOTE=Adams' Apple]If the trans is set-up for a hydraulic LU, it will ONLY go into LU at a specific road speed(mph)...the TV cable adjustment will have no effect on it.
In your case, you may need to have the spring changed in the LU valve to a lighter one, so it will lock-up earlier. The kits for this normally come with at least three different springs, so the LU apply can be tailored to work at different speeds.
You should be able to feel when it goes into lu, just after the shift into 4th(around 45mph). Depending on what spring tension was used, it may not lock-up until later. There is also a check-ball that must be installed into the snout of the lu solenoid for this to work. If the ball was not installed, the trans will never go into lu.
One way to determine if the lu is working, is to watch the tach. After the shift to 4th, you should be able to see the tach drop down a couple hundred RPM once the converter does go into lu. Once the converter locks up, applying small amounts of throttle should not raise/jump the rpms. If there is no lu, the rpms will raise considerably with just slight throttle.

That being said, there are some folks that will install the ball in the lu solenoid, without using the correct lu valve line-up. This creates lu from 2nd gear up, regardless of throttle, or road speed. It also makes the shifts a little "lunge-y", or rubbery. There are some valve bodies, the late '86 and ups, that do not have a place for the lu valves. These vbs are strictly computer controlled, as far as lu. These should not be used for this application, for this reason.

                                                        More info on lu valve[/QUOTE]

Hey Josh!

Do you have it WIRED to lock up? In my case I have a vacuum switch piped to my intake that closes @ 8" hg Vacuum in series with a switch that is closed with no brake application, then in series with the transmissions 4th cog pressure switch. If all the above switches are closed the trans will lock up. If you're not in top gear or are accelerating or braking, the converter unlocks....

Joel,

That's the valve I had researched, but a different mfgr. When I get 'lectric in my garage to run my lift I'm gonna get one.

DaveAutom8r2007-11-05 07:20:03

[QUOTE=Autom8r]Hey Josh!

Do you have it WIRED to lock up? In my case I have a vacuum switch piped to my intake that closes @ 8" hg Vacuum in series with a switch that is closed with no brake application, then in series with the transmissions 4th cog pressure switch. If all the above switches are closed the trans will lock up. If you're not in top gear or are accelerating or braking, the converter unlocks....

Joel,

That's the valve I had researched, but a different mfgr. When I get 'lectric in my garage to run my lift I'm gonna get one.

Dave[/QUOTE]

Josh,

Everything about the transmission IS hydraulic..... except the lockup, which uses an electrical signal to a lockup clutch soleniod.

Hang around here long enough and you'll be a whiz kid!

Dave

He said even that was controlled hydraulically by a kit. So I dunno. I havent had it on a lift yet, but I dont remember seeing any electrical cables going to the tranny

It's just one wire. A lot of guys use a toggle switch to lock it up, but then they forget to unlock it when they hit the brakes and stall the engine. It's a fairly simple hookup to have it autom8d...

Dave