700r4 tv valve assembly problem

[YoungPup1977]

Here is the pin that once the tv cable is pulled the pin pushes up on the pressure relief check ball. So it’s off the seat of the VB.
Second pic shows when the cable is pulled the pin moves upward to move the checkball off the seat in the VB.

I really don't think this is your issue, I am leaning towards as mentioned above is the TV valve itself.

Are the rear wheels off the ground, which enables you to run the vehicle in gear with the wheels off the ground. this may allow you to figure out if the transmission is actually shifting at all.... With the wheels off the ground, manual shift the transmission from low to second, than second to 3rd, 3rd to 4th and see if it shifts real late or early....

[frankslagoon]

Hmmm. So 2 questions, what would I do if the relief valve is set. and I'm checking pressure at the plug above the shifter, is that correct? I didn't notice the pin your talkin about, darn it, but will look at your pic when it comes up. thanks.

[frankslagoon]

Awesome pics. I'll pull the pan and see what's up. I think I'll order a TV upgrade kit. any suggestions.

[YoungPup1977]

Originally Posted by frankslagoon

Hmmm. So 2 questions, what would I do if the relief valve is set. and I'm checking pressure at the plug above the shifter, is that correct? I didn't notice the pin your talkin about, darn it, but will look at your pic when it comes up. thanks.

The pin as outlined in the pic would be pushing up onto the pressure relief checkball if the TV cable is adjusted correctly.

Pressure gauge is connected correctly at that location. Above the manual shift lever on drivers side of trans case.

[YoungPup1977]

Originally Posted by frankslagoon

Awesome pics. I'll pull the pan and see what's up. I think I'll order a TV upgrade kit. any suggestions.

Before pulling the pan off again, can you run the transmission in forward gears with the wheels off the ground just to see if it is shifting at all. If is does not shift at all, than I would take pan off and remove the VB and check the TV Valve for movement.
I can provide pics of this TV valve as well along with which roll pins to remove to get TV valve out of the VB bore.

With the pressure at 150, is directing our attention to the TV Valve........not the governor at this time.

Also, maybe this trans 2/4 band is totally burned up. This is a junk yard dawg trans right ? You would never get a shift to second if that’s the case

[YoungPup1977]

Here is a pic of the pressure gauge port. Sorry the case has not made it into the washing cabinet yet so it is real dirty but you can see the port above the manual linkage on drivers side of case

[Chris_oz]

Hi all,

I put a TH700 in my Cadillac a few years ago and had some similar issues before I drove it.

The TV "valve" will be loose in the bore, if you don't have the cable connected at the carb or adjusted tight enough, there will be "freeplay" between the end of the valve and the lever which pushes it.

Once adjusted correctly there wont be any free play.

There is a very specific way that the cable and bracket needs to be set on the carb to work.
Most manufacturers have the correct pin and geometry in the carb specs.

If you don't set it right you will have late shifts, low TV pressure which may cause burned clutches if pushed hard.

As stated, later model trans had a "safety" in them so if the cable snapped it gave you full TV pressure, this would give very harsh, late shifts, but a safe pressure for the clutches.

once you have the correct brackets and mounts for the cable on the carb, you can get a pretty good setting by adjusting the cable until it is TIGHT with throttle at WOT, so you really cant pull any slack in the TV cable, at closed throttle, there will be some tension on the cable, this is from the springs in the TV valve.

Don't try and check pressure before you have the cable hooked up and adjusted, you are wasting your time.

once you have the TV cable adjusted, then you can drive it, you may need to adjust the GOV, as the heavy truck will have different shift points than a sedan.

http://www.tvmadeez.com/article/

[frankslagoon]

Ok back form my errands. with TV cable disconnected I have 150 in all gears except reverse kicked up to 225 ? The tranny auto shifts trough all gears but needs 3500 rpm to start shifting. then it runs up through all 4. Hook up TV cable same thing. if I pull hard on the cable the pressure actually goes down 30 or 40 psi at idle. idle is 800. if I turn the idle down to maybe 600 the pressure starts to drop but the motor won't run much lower.

[Chris_oz]

Originally Posted by frankslagoon

Ok back form my errands. with TV cable disconnected I have 150 in all gears except reverse kicked up to 225 ? The tranny auto shifts trough all gears but needs 3500 rpm to start shifting. then it runs up through all 4. Hook up TV cable same thing. if I pull hard on the cable the pressure actually goes down 30 or 40 psi at idle. idle is 800. if I turn the idle down to maybe 600 the pressure starts to drop but the motor won't run much lower.

Hi,

Good to see it upshift, means the trans is probably OK.

Now you need to hook up the TV cable and adjust it, tyring to do tests without doing this has no point.

What carb do you have?
Do you have a bracket to hold the cable?
I made one that picked up 2 of my manifold bolts and set the cable to sit in the correct alignment to the throttle shaft.

[frankslagoon]

I have a 4160 model Holley. I have a bracket. I ordered a corrector plate and a transgo jr. kit for the valve body. I'm thinkin the tv valve is stickin. Looks like I need to drop the valve body to get at the pin that holds the tv valve in. I think I can get the plunger pin but looks like there is another pin that holds the tv valve in. is that correct?

[Chris_oz]

Originally Posted by frankslagoon

I have a 4160 model Holley. I have a bracket. I ordered a corrector plate and a transgo jr. kit for the valve body. I'm thinkin the tv valve is stickin. Looks like I need to drop the valve body to get at the pin that holds the tv valve in. I think I can get the plunger pin but looks like there is another pin that holds the tv valve in. is that correct?

Before you put the transgo kit in, try it with the cable hooked up. It is doing exactly what it is supposed to be with the cable disconnected.
You are pulling on the cable against the spring and hydraulic pressure when it's running, and the pressure dropped.
Get it set and try it before you pull it apart, my bet is that there is nothing wrong with it.

[frankslagoon]

ok I'll set it up in the morning. it's 2230 here Tuesday.

[Chevyrestorerman]

Glad to see you got it to shift, moving forward is a good thing.

maybe the TV valve is not stuck after all and all thats required is getting the cable adjusted correctly.

There are so many articles on the 700R4 TV cable on how it works and how it should be adjusted.

Looks like you are on your way!!!

[frankslagoon]

Update. Soo, I adjusted my cable and fired him up. 800 rpm. the pressure is around 75 psi. bring it up and I get 150. more in reverse. shifts through the gears at about 1900 rpm. That's pretty good. I'm gona stop here and get a couple things straighted out. My carb is a 750 and that's to big, I'm gona put a 600 on. before I do I'm gone bolt the new tv lever that's coming in the mail. and the drive line I cut down is vibrating.I'll get that fixed this week also. Then test drive, That stuff never held me back when I was 20 ? thanks guys. I'll probably put the transgo kit in. but after I get it everything working.

[YoungPup1977]

Originally Posted by frankslagoon

Update. Soo, I adjusted my cable and fired him up. 800 rpm. the pressure is around 75 psi. bring it up and I get 150. more in reverse. shifts through the gears at about 1900 rpm. That's pretty good. I'm gona stop here and get a couple things straighted out. My carb is a 750 and that's to big, I'm gona put a 600 on. before I do I'm gone bolt the new tv lever that's coming in the mail. and the drive line I cut down is vibrating.I'll get that fixed this week also. Then test drive, That stuff never held me back when I was 20 ? thanks guys. I'll probably put the transgo kit in. but after I get it everything working.

At this point I would not put the transgo kit in it, drive it awhile to see how it upshifts and downshifts. If the shifts are a bit stacked I would put different springs in the gov to improve the shift points.
I like to use the two yellow springs out of the Transgo SK350 kit in the 700R4 gov as a "starting point", not every 700R4 gets the same springs and weights on the gov....
also, I have used a T350 gov in a 700R4 with good success.