700r4 tv valve assembly problem
 

I'm installing a 700r4 in a 67. my first 700r4. I fired up the car at the salvage yard and the tranny seemed to go into drive and reverse well. I have the tranny in the trk now and dropped the pan to adjust tv valve. the plunger doesn't spring all the way out by itself. the plunger moves freely but doesn't seem to have spring pressure about the last quarter of travel. That doesn't seem right to me. ?

Re: 700r4 tv valve assembly problem
 

First, what adjustment are you making in the pan?

And no, there should be slight pressure on the plunger even when fully extended.

It sounds like the TV valve is stuck. The aftermarket sells a small spring that can help push the valve rearward. Transgo sells a kit that replace the TV valve completely with one of it's own design.

What year is the trans? 92-93 are difficult to get the TV out without a special tool as the roll pin is in a small circular well rather than a rectangle bowl.

Look here

Re: 700r4 tv valve assembly problem
 

I am in the process of installing a 700R4 in my 72 swb big block truck and I adjusted my cable at the carb end of the cable.

Before you dropped the pan did you try to adjust the cable to see if it changed the shifts ?

Are you having late shifts or early shifts into 2nd ? or does it shift at all ?

Re: 700r4 tv valve assembly problem
 

OK, Some guy puts a nice roller cam 350 motor and a 700r4 in a jaguar. Fires it up and something goes wrong. burns it to the ground. melts carb down etc. I pull intake clean it up , put a new carb on dist. wires etc. fire it up, runs good. put the tranny in forward and reverse, seems to shift in solid. I pull the works out. drop it in the 67. I use a throttle TV bracket off a newer trk. I use a aftermarket TV cable , the kind that you adjust the length of the cable housing, seems pretty solid. As I said earlier, this is my first 700r4 so I'm not sure I got the right adjustment or the geometry at the carb is correct. So I figure I'm droppin the pan anyway to put a new filter in, so I'll adjust the cable while I'm looking at the plunger and make sure it's working correctly.Tranny is super clean new porks torque converter, looks good inside. But when I bring the plunger lever back the plunger stops with 2 rings left in the tube. I can easily move it the rest of the way out with my finger. pretty sure that's not working correctly. I don't know what year the tranny is. probably the hard one to get apart

Re: 700r4 tv valve assembly problem
 

Seems like once the tv valve is pushed in there is no reason for it to want to come back with no fluid pressure. there doesn't appear to be a spring or any mech. reason for the valve to be forced back just because I bring the plunger back.

Re: 700r4 tv valve assembly problem
 

Maybe a picture of the plunger / tv valve area with the cable connected may show something.

maybe I missed something here, you changed the filter before you installed the trans without any fluid in it or now you changing the filter after you put fluid in it and noticed the tv plunger thingy not working.

Re: 700r4 tv valve assembly problem
 

I put the tranny in before I pulled the pan and drained it. Doesn't really matter, question is , what forces the tv valve back out, the only mech device is the spring between the plunger and the tv valve. I can't see any reason for the tv valve to move back out without some line pressure on the front of the valve. but when I watch some videos the plunger comes all the way back. mine stops short and I can slide it the rest of the way very easy with my finger.

Re: 700r4 tv valve assembly problem
 

Did it shift at all.

Maybe a stuck valve as mentioned above.
Did u look at the thread where it shows the TV assembly in the VB ?

Re: 700r4 tv valve assembly problem
 

True, in a stock setup there is nothing but hydraulic pressure to move the valve rearward. So your's might be fine.

The transgo and aftermarket solutions have a small spring to push the throttle valve, spring and plunger back.

So you haven't started it? I wouldn't worry unless you have a delayed shift that can't be corrected with cable adjustment.

Re: 700r4 tv valve assembly problem
 

No I haven't started it yet. just seemed like something to check on before I put the pan back on. It did go into fward and reverse good in the doner car, but I couldn't drive it. I think it's ok but Monday I'll go to yard and check out acouple other 700r4s thanks

Re: 700r4 tv valve assembly problem
 

The salvage transmissions can cause more headaches than one would want. I hate to see you pull the transmission back out because the cable is not adjusted correctly.....I dont know if it even shifted so I am only throwing darts in the air here. Maybe its the governor, who knows. no idea what it was doing .

I bought a rebuilt 700R4 and it works great the first time out plus its something I can drive anywhere I need to without worrying its going to leave me out in the tundra. Hope the salvage transmission works out for you.

Re: 700r4 tv valve assembly problem
 

Thanks chevyman, if you can't explain the mech of the Throttle Valve to me and have adjusted one at the tranny you probably won't be able to answer my question

Re: 700r4 tv valve assembly problem
 

I know I can not explain how to adjust the TV valve assembly because the TV valve assembly is not adjusted at the Valve body.

With the pan off, get your buddy to push on the gas pedal while you watch the TV plunger in the VB, check to see how far the travel of the plunger goes and ensure the TV valve moves freely. How hard can it be.

transgo makes a self cleaning TV valve, maybe since you already have the pan off replace the TV valve and take the assembly apart and use the reference material that was referred to in a post above.

Maybe its the cable itself, not pulling on the plunger enough, maybe pulling on it to much.

You don't answer the simple questions so how do you expect someone to assist you.

again, before you pulled the pan, how did it shift ?
you pulled the pan off because of what ? not to change the filter, which you should of changed before you did anything with the salvage transmission.
you pulled the pan off because the transmission was not shifting right ?

Need to set the cable using a pressure gauge which is the "correct way" of making sure the cable is adjusted correct. If not, which everyone on this forum will agree, it will burn up your 3-4 clutches. seen it happen over and over again.

Do a search on 700R4 TV cable adjustment and you will see for yourself on how the TV valve works. Can you take a pic of the valve body with the cable connected and with the cable disconnected.

Take the two bolts out of the valve body that holds the arm that pushes in on the TV plunger. maybe the arm is bent, being a junk yard transmission maybe the cable was pulled and bent the arm.

Just trying to help but help me help you.

Re: 700r4 tv valve assembly problem
 

I don't know the answer to your question. But this thread may help you. If not try posting your question (or PM Clinebarger) in the thread. He is a wealth of knowledge. He talks briefly about spring preloading the TV valve about 3/4 of the way down the page.

http://67-72chevytrucks.com/vboard/s...=634121&page=8

Good luck with your search.

Re: 700r4 tv valve assembly problem
 

From the bottom of the VB you most likely can not determine if the tv valve itself is moving or stuck. Removal of the VB will be the only way to determine this.
As far as the number of rings showing on the plunger, you can push the plunger in until it gets spring tension which will show 4 rings outside of the VB. This is normal. With the plunger all the way out will show 6 rings. See pics.
So when you have 6 rings showing on the plunger, you should be able to push the plunger in to where only 4 rings showing without any spring tension.
Since you have the pan off, With your tv cable hooked up is your plunger pushed in with how many rings showing. Let’s start here.

Re: 700r4 tv valve assembly problem
 

Also no one has said this but on a 700r4 the tv is not used to adjust the shifts just the line pressures, if the cable is not adjusted properly the trans can burn up in as little as 20 miles proper way to set is using teh gm method and the verify using a trans guage and pressure chart

Re: 700r4 tv valve assembly problem
 

Perfect, thanks guys. I adjusted the cable so I have 6 rings at closed throttle then slide plunger in to spring tension and show 4 rings. and WOT the plunger is pushed all the way in. I should be good , at least on the TV valve setting.

Re: 700r4 tv valve assembly problem
 

OK, next question. the speedo output assembly on the 700r4 is a smaller dia. male thread then the output from the pglide anyway the end of the cable that went to the powerglide slips right over the threads on the 700r4 are there different speedo assemblys for the 700r4 or does someone sell a conversion.

Re: 700r4 tv valve assembly problem
 

check out : WWW.LASPEEDOMETERGEAR.com

Re: 700r4 tv valve assembly problem
 

Ok I sent em a email,meanwhile I'll try some other cables. thanks

Re: 700r4 tv valve assembly problem
 

So here's an update I set the TV cable by looking at the tv plunger. But just to be sure I put a pressure gauge on the tranny. I'm showing 150 in all gears. idle or throttled up. The car I got this from as mentioned before had a engine fire. melted the carb and TV cable was have gone. I replaced the intake carb dist. etc. and fired it up. tried the tranny , just put in forward and reverse and it worked. is it possible that the tranny went into fail safe without the TV cable hooked up when I first started it.

The 700r4 does not have a fail safe mode so that is not your problem

Sounds to me the cable needs to be adjusted correctly. 150 in all gears doesn’t sound right.
Start by lifting up the tab on the adjustment up near carb. Push the gas pedal to the floor. Push on the tab adjustment to lock cable in that position. This is a good starting position.

The cable is not “adjusted” at the Valve body.

Can you supply a pic of your cable at the carb area.

Check your pressure in each gear Let us know.

Re: 700r4 tv valve assembly problem
 

As mentioned the pressure in most ranges at minimum TV is around 60-70. Your pressure is closer to maximum TV.

Likely it's the TV valve, in the valve body, is stuck forward

There is a "fail safe" if the cable breaks or becomes disconnected but most rebuilders throw that check ball out during an overhaul.

Re: 700r4 tv valve assembly problem
 

I'm haven a hard time to post pics. the pressure stays the same no matter what I do with the cable. I know the plunger was all the way out ( 6 rings at idle and all the way in at WOT. But it would not come back past 4 rings on its own I had to slide it back with my finger. which seems reasonable be cause there is no spring behind the TV valve. could be a stuck valve. The reason I ask about the fail safe ball is the cable was burned off at the intake manifold before I started the motor. I haven't driven it so I don't know how it shifts up or down, just that it shifts into forward and reverse, rigs still on the blocks in the garage. So if the fail safe ball falls in because the pressure was to low when I fired it up how do I reset it?

Re: 700r4 tv valve assembly problem
 

The pressure relief checkball when seated all the way will create hard and late shifts. The term "reset" is not a option.

Did you notice on the arm that pushes in on plunger have a pin that pushes on the checkball thru the VB, this pin maybe broken off.....while pan was off would of been a good time to check the operation on this. I will take a pic and provide what I am referring to.