The 1947 - Present Chevrolet & GMC Truck Message Board Network

The 1947 - Present Chevrolet & GMC Truck Message Board Network (https://67-72chevytrucks.com/vboard/index.php)
-   The 1967 - 1972 Chevrolet & GMC Pickups Message Board (https://67-72chevytrucks.com/vboard/forumdisplay.php?f=3)
-   -   valve body in 700r4 - no spring? (https://67-72chevytrucks.com/vboard/showthread.php?t=169620)

guyryan100 08-21-2005 06:24 PM

valve body in 700r4 - no spring?
 
1 Attachment(s)
Ok, so my 700r4 is stuck in first and the govenor is fine, also TV cable is set and working correctly. So I dropped the valve body hoping to find some trash in a valve or something. Found no trash but did find this:

One of the valves (see pic - the one boxed in blue) does not pring back into its closed position when I slide it open. All of the other valves do. Could this be my problem, and if so how do I fix it?

chickenwing 08-24-2005 03:47 PM

NFC. Just wanna see the answer too.

Jwill41 08-24-2005 07:33 PM

I cant help either but sure am glad to see that pic. I was wondering what I would find if I dropped the valve body. Mine is working better now but takes off in 3rd or 4th unless I slightly tap the gas peddle when taking off.

VetteVet 08-24-2005 10:21 PM

Looking in my Haynes manual "10360" GM sutomatic transmission overhaul on page 8D-22 it shows a valve body on the 700 R4and says that if you take a small screwdriver or pick and pry against any of the valves they should snap back to the closed position.
In the troubleshooting section, it says under -will not shift out of first- 1/2 valve stuck in the valve body.
There should be a small pin holding each valve in place. If you drift it out the valve should come out. You may have a weak spring or a burr causing the valve to stick. Hope this helps.

86k10 08-25-2005 12:46 AM

The valve you have in question is the TCC valve. Go up three and you have the 1-2 valve train. Just curious but what is that red stuff you have holding the checkball?

chickenwing 08-25-2005 10:58 AM

Quote:

Originally Posted by 86k10
The valve you have in question is the TCC valve. Go up three and you have the 1-2 valve train. Just curious but what is that red stuff you have holding the checkball?

TCC? Could ya define that for me? Thanks.

72MARIO 08-25-2005 01:17 PM

Vett Vett,

You seem like you know your stuff. I have a 700r and on ocasion when cold under light acceleration the 2nd to 3rd shift misses pops out of gear and if you let off the gas then lightly tap the gas it will pop into 3rd. Only happnes when cold. What could be causing that ?

Thanks for the help

86k10 08-25-2005 02:56 PM

Yeh I should have written it out, it stands for Torque Convertor Clutch. But you still didn't tell me what that red stuff holding your checkball is :lol: And to give a possible cause to Vett Vetts problem, it more than likely is the front sprag getting worn, I've seen that before.

Jwill41 08-25-2005 07:03 PM

Not wanting to hijack this thread but can anybody help with my problem? It does not downshift after coming to a stop. A light tap on the gas and it takes off normal. Without the tap of the gas it takes off in 3rd or 4th, I dont know which.

86k10 08-25-2005 11:33 PM

Are you certain it's in 3rd or 4th, probably 2nd. Does it work fine after that?
And I'm still waiting for Guyryan to tell me what's holding that checkball :lol:

VetteVet 08-26-2005 01:04 AM

700 r4 stuff
 
Quote:

Originally Posted by 72MARIO
Vett Vett,

You seem like you know your stuff. I have a 700r and on ocasion when cold under light acceleration the 2nd to 3rd shift misses pops out of gear and if you let off the gas then lightly tap the gas it will pop into 3rd. Only happnes when cold. What could be causing that ?

Thanks for the help

If you are refering to me then you have overated me. I have a lot of automotive experience and am somewhat familiar with the automatic trannys. 86k 10 is the expert and he works on them a lot. I saw the red stuff on the checkball too and was wondering what it was.
From what I read about your shifting problem the book lists several probable causes. It's like asking why is my engine missing. There are so many reasons that it will slip or not shift that it may take a teardown to find the culprit. Two that may cause the problem are govenor weights and springs and tv cable not adjusted correctly. There are several references to the clutches and that is why 86k 10 asked if it worked ok after it shifted into third.

Jwil41 It sounds to me like you may have a sticking TV cable . The TV valve controls downshifts as well as upshifts. Take the cable off the carb and work it by hand and see if you feel any binding.

Jwill41 08-26-2005 09:50 AM

I have had the cable disconnected several times and it works freely. I have looked at the govenor and it moves freely.

Also when I go to reverse from any forward gear it feels like it is "locked up" and the truck will not move. If I go to park then reverse it works ok. This happened after towing a truck 200 miles in the Texas heat with only an auxiliary cooler. I have no tank in radiator. I know, what a stupid thing to do. :rolleyes:

72MARIO 08-26-2005 10:41 AM

Oky I kinda figured that it's going to have to be removed and rebuilt angain. The tranny works fine thru all the gears just on occasion it cant find 3rd and then it bangs into 3rd and nicely into 4th.

I really dont want to remove the tranny. Oh well.

dmec 08-27-2005 12:21 AM

the red stuff is probably trans assembly lube. it is actually auto trans fluid mixed with vaseline. it is used to lube the seals for installation and to retain the check balls during assembly.

guyryan100 08-28-2005 08:02 PM

Wow - I though this thread was lost. Thanks for the replies so far. Yes, the red stuff is assembly gook. And quite handy in keeping those check balls off the garage floor. If that valve is the TCC valve, could it impact my 1-2 shift? (still awaiting tranny book from library). Interestingly, the valve that's marked in the pic above does not exist on the valve body of another 700r4 I checked....

Here's a fluid diagram I found on the chevelles site - not exactly applicable but for those searching for info, maybe this will help.

http://img200.imageshack.us/my.php?i...icdiag25iv.jpg

guyryan100 08-29-2005 08:44 PM

Well I talked to two tranny guys today - took my valve body to two shops to ask their ideas. Tranny guy 1, an older guy, told me that this valve was deleted in the design around 1984 (my tranny is '86) and that the always-open valve was a normal result. He said he thought my stuck-in-first problem was something deeper in the tranny.

Tranny guy #2, the rastafarian, said that rebuilders often leave the spring out of that valve to create harder shifts and that it was no problem, but that I was missing 2 check ball valves - one in that jelly-bean shaped spot on the top left corner of the pic above and one off the pic on the right. He seemed sure that these two check balls were my problem and that I should bolt it up and be done with it.

Would have been nice if the old guy and the rastafarian saw it the same way... anybody ever leave out the check ball and find themselves stuck in first?

86k10 08-29-2005 10:39 PM

Any vehicle that had an ecm didn't have that valve in it which started in 86 but the bore for the valve was still there it was just filled by 2 aluminum plugs and they did that until the 90 model year when they deleted the bore as well. Which is nice because you can take a later trans and install the valve train in there and it will function without an ecm just like the older ones. The TCC valve has nothing to do with anything but controlling the TCC lockup. It reacts off of TV pressure and tells it when to lock and unlock depending on throttle position. It has nothing to do with the shift patterns at all and yes you should have a total of 3 checkballs on the valvebody itself.

VetteVet 08-29-2005 11:52 PM

more 700r4 stuff
 
I found this website where a guy tells about rebuilding the 700 and a lot of other stuff. Check the FAQS and read what he says. It might give you a clue on yours. You have me at a disadvantage, What's a rastafarian?

http://www.technicalevolution.com/faq.htm


All times are GMT -4. The time now is 09:37 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright 1997-2025 67-72chevytrucks.com