700R4 Shifting Problems

TomSawyer · April 16, 2009, 10:53:33 PM

My son's truck one day stopped shifting from first into second, third and overdrive. A very knowledgable Chevy person said it was straight up governor problems, broken gear or stuck valve / piston. The governor gear was not stripped or broken but the piston was stuck. I replaced the malfunctioning governor with a used functional one and the transmission began to shift correctly, at least at first. The truck now is reluctant to shift into second and third but will do so at much higher RPMs than usual. Not sure about overdrive, I'll need highway speeds to test that. I serviced the transmission, new filter screen and fluid, but it's still behaving the same. Any thoughts or ideas? Trannys are expensive so any help is much appreciated. Thanks

Crosley.In.AZ · April 16, 2009, 11:22:33 PM

You need to verify the TV cable adjustment.. minimum setting is important too.

Full pull of the TV cable at WOT is best place to start.

visit this page for info and specs:

http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html

TomSawyer · April 16, 2009, 11:33:00 PM

Thanks for the reply. Replacing the governor resolved, for a short time anyway, the shifting from first into second and third. How would the adjustment of the TV cable resolve the issue the truck is having now? The cable didn't need adjusting when the governor was first changed. You thoughts are much appreciated. Thanks.

enjenjo · April 16, 2009, 11:51:30 PM

The TV cable controls the shift points. the cable can get out of adjustment, or even stretch over time.

WINGNUTZ · April 17, 2009, 12:20:08 AM

Quote from: "enjenjo"The TV cable controls the shift points. the cable can get out of adjustment, or even stretch over time.

I just switched out a T400 for a 700R4 and set the TV cable to be fully extended at Full Throttle... however My car is really light and requires very little throttle to scoot down the road and my shifts are very quick up to 3rd!

I noticed that when I let off the throttle... the cable seems "Slack"... is this "Right"

Were these some of the symptoms you were having before your governor change?

TomSawyer · April 17, 2009, 12:20:08 AM

After changing the transmission governor, the problem of shifting seemed to just go away, at least for a few miles. After about 4 to 6 miles of stop and go traffic, the high RPM shifting delay problem occurred. Cable stretch in this circumstance isn't the issue, that's more of a long term circumstance. Thanks for all the input, it's very helpful.

Crosley.In.AZ · April 17, 2009, 08:30:20 AM

Quote from: "TomSawyer"After changing the transmission governor, the problem of shifting seemed to just go away, at least for a few miles. After about 4 to 6 miles of stop and go traffic, the high RPM shifting delay problem occurred. Cable stretch in this circumstance isn't the issue, that's more of a long term circumstance. Thanks for all the input, it's very helpful.

As I posted , check the TV cable. Minimum setting is important too since:

Late shifting can be an indication of the fail safe check ball that has seated. Trans will then shift late , like the vehicle is at WOT.

TV cable adjustment is plastic parts , may have broken , shrunk enough to allow the cable to slip out of adjustment

The governor may have stuck again , which is an indication the trans is creating metal.

What is the mileage on this transmission , if known. An Old unit , recent rebuild or recent service work?

Since you are new to the RRT ; I do not get my trans information from the internet , It is decades of experience

BFS57 · April 17, 2009, 10:00:21 AM

Hello;
The TV adjustment ia very important! It is also very touchy! You have to make sure it is adjusted properly! Believe me, it makes a very big difference! You will realize that a minute adjustment makes a very big difference!!

Bruce

TomSawyer · April 17, 2009, 02:53:45 PM

The transmission has 168K miles and has never been rebuilt or removed etc. I serviced the transmission and did see some metal around the magnet but nothing unusual. It wouldn't hurt to check the TV cable measurements but I just can't see how a transmission would work completely fine one day, not shift into second the next, have a governor replaced another day and go back to shifting just fine again, and then a few miles later start shifting at higher shift points. With each mile it seemed to get worse. It would be a coincidence if the TV cable did get out of adjustment right after replacing the governor. A tranny mechanic I kinda know said to expect sticky valves and such because the transmission was well overdue for a service. I'm gonna figure this out, it's only a matter of time.

TomSawyer · April 17, 2009, 03:11:39 PM

Hey wingnutz,
I never looked at the TV cable so I can't really say much about your "slack" issue your having. All I know is the tranny wouldn't shift up and the guy said it was straight up governor issues. I replaced it and it worked great for a short while. It then started shifting at higher RPMs. Sorry I can't be of any help.

wayne petty · April 17, 2009, 06:31:39 PM

wingnuts...

which carb do you have... there is a difference in distance from the center of the throttle shaft of TH350 detent linkage pivot point and the 700R4 linkage attachment point...

the 700R4 takes an adaptor to move the throttle valve cable link farther away from the center of the carb shaft... this gives it a different pull vs angle ratio.... so it will have slack at idle when the cable is adjusted for WOT...

holley sells the linkage adaptor at most parts stores...

her is a link to a picture of it..
http://www.transmissioncenter.net/AS3-03K.jpeg

here is a link to a description of a 200r4 info sheet

http://www.transmissioncenter.net/2004RTIP.htm

same info as you will need for the 700...

WINGNUTZ · April 18, 2009, 09:38:40 AM

Here lies the problem for me... if I move the cable farther from the center... the cable will be more slack in the returned position!

I have a dual quad with Edelbroch 600's and the TV is set on my primary carb to control shift points and when I set the cable for WOT it feels slack in the returned position... and I don't know if there's enough tension while cruising down the road at 1/8th throttle!

Should I be looking at a governor change like Tom or will I be experiencing the problems that are noted in the beginning of this thread???

wayne petty · April 18, 2009, 10:15:45 AM

i am trying to remember the distance from the center of the throttle shaft for the exact location of the pull attachment . (+--------------+)

i don't have any gm throttle bodys handy... or later model gm carbs.. should be electronic feed back..

but i am going to the junk yard right now... if i remember.. i will see what i can find so i can measure it..

34ford · April 18, 2009, 11:53:12 AM

Quote from: "WINGNUTZ"Here lies the problem for me... if I move the cable farther from the center... the cable will be more slack in the returned position!

I have a dual quad with Edelbrock 600's and the TV is set on my primary carb to control shift points and when I set the cable for WOT it feels slack in the returned position... and I don't know if there's enough tension while cruising down the road at 1/8th throttle!

Should I be looking at a governor change like Tom or will I be experiencing the problems that are noted in the beginning of this thread???

You need this adapter for the carb to set the right geometry. Bought mine at summit. have them for both edelbrock and holley

page link http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-700202&N=700+115&autoview=sku

bc

WINGNUTZ · April 18, 2009, 03:26:59 PM

First of all let me apologize for "Hijacking" this thread... Should I just start another thread?

But this has raised many questions and could use the help so that I don't end up asking the same questions the original poster has brought up!

I've seen this bracket before but it says it's for Holleys... and I don't see a lever for the Edelbroch's.

Would this work for both?

Plus I don't have much room under the lever to clear the manifold and I'm wondering if this will hamper the operation?

Thanks

Mark