It has to be a reluctant valve in the valve body. Again from everything you have described, one of them is causing a fault. Remember, the governor works in sequence with the other valves. If you look at the schematics (you will see when I pm you one from my book) it will be clear how all the hydraulic circuits work together. Line pressure, gov pressure, throttle oressure...
Any good mechanic will tell you this transmission is has Milage on it can be a lot of things starting to fail... Yes it's going to have to be rebuilt from the ground up....
The prob is a sticking valve as it returned to normal a few weeks ago, so while it seems like a big problem, it's a hidden little flaw, I will find it!
+CORVAIRWILD did you ever find out what the problem was?...My 85 GMC 700R4 started out fine then no second gear, it jumps from 1st to drive ...then later on overdrive stops working after the transmission fluid warms up....
I know this is a old thread but first thing or few things would be TV detent cable adjustment, then governor by taking the pin out and valve and gear off cleaning it check to make sure the valve is moving up and down probably, then the fluid levels and filter.
I tried everything to get that tranny to shift, new valve body, governor etc. it's still lying in the same place, one day I'll open it up. The Torque Convertor is seized on, pia
I cant find anything on why my 700r4 wont shift in my 4x4. Everyonce in awhile if i take off in low and get to about 25 mph it will go in second and get to about 40 mph it wont do anything else
Oblivion_Army I took off my valve body so many times to correct my non shifting problem. I put a new throttle valve cable, a new spring, I cleaned the valve body, I rebuilt the valve body, put a new valve body on, and nothing worked. I eventually changed the transmission, and I never opened it up to see what failed.
check the line pressure on the trans , google it , there are ports to install a gauge , it sounds like the pressure is down , and comes back from time to time when it works right , their is a pressure relief valve just like in the engine oil pump , I am sure you have seen an engine oil pump get a piece of valve seal in the relief valve before , you might have a small piece of clutch facing causing all of this ...
Good point, I'm almost ready to buy a reman valve body, but didn't think that was the prob. Is the relief valve in the pump pressure valve? I'm familiar with modifying the valve for a shift kit
CORVAIRWILD it is in the bottom of the front pump , you can see it with the pan off , it has a c-clip that holds it in , it is string loaded , there are 5 parts in there , from the clip in , you will find ... the clip , the boost valve and sleeve , spring , and the valve rod , there are a few o-rings on these parts , I bet it's junk in there , or a hard or broken ring , some times they don't want to come out , their is an easy way to get it out , you have to remove the c-clip , rreinstall the filter and pan , add a couple quarts of fluid , start it , and put it in reverse , you will hear it leave the pump as it pops it out , don't let the wheels turn , and shut down right afterwards , I have had this issue more than once ;) there are only 3 things that can cause this issue really , one is this pressure reg valve , the other two are governor , and the TV cable , by the way , set that cable back correctly , a loose cable will trash that trans , note the TV cable being set anywhere will still let it shift , as the governor will take control when it gets to high RPM's , and that is what leads me to the pressure reg , as it has to have pressure to apply the clutches and make the shift , without pressure the throttle valve , or the governor neither even if working right will make the shift , they are making the call , but the pressure is not there to make the shift ... so how many of these transmissions have I broken , well you don't have enough trucks cars , and trailers to haul them , I killed 1 or 2 a week for years being young and dumb , ever wore out the threads in an engine block bellhousing ha ha ha I have lol
towrecker I didn't hear from the tranny place, I'll try him again tmrw. So is the boost valve the prob GM had with excessive wear as it is always moving, and wears the bore?
CORVAIRWILD yup and they always buzzed too from time to time , the boost valve is on the passenger side of the teeruk beside the hole the filter plugs into , and the pressure reg is on the drivers side , checking both might be worth the time too
those drain plugs suck, welded the hole up in two of my pans, nothing but leaking junk. Btw parts washer, can make them out of old dish washer, beats paying for brake clean. brake is for one thing, cleaning drums and rotors of dirt and grease imo.
Lesson 1 drain pan see how much metal is in the pan. If it looks good not much metal change the filter clean pan with brake clean . Clean silicone off Governor cover brake clean it too. Governor valve hold it and press both butterflies to see if valve is moving up & down . If the valve don't move take out roll pin & clean valve sleeve. if that valve is stuck Transmission will not up shift it will start off in 2nd gear . Do not use silicone on pan just a small bead around Governor cover. Use Cork pan gasket for pan not the black crappy one that comes with a filter kit ? Go over each hole on the pan where the bolts go thru & Hammer down them flat with a punch or ball peen hammer . Put new cork gasket torque bolts down. Put 4 liters in transmission start it up Check fluid . Jump in put it in reverse check fluid again . Let it warm up check fluid again ! Then when it's all level take it for a ride but drop it into 1st gear and shift Manual 1-2-3 drop it to 1st again 1-2-3 again same thing for 2 km . What this does is free up that Governor valve so it does not stick . If you put it in drive and it starts shifting normal again you did it right ! If it starts off in 2nd gear from a stop then pull governor gear out again free up valve or replace it !! Hope this helps !
luis freitas I tryed a different valve body and governor, nothing helped. I never disassembled the old tranny, the convertor is seized into the input shaft. One day...
Throttle valve cables and the throttle valves themselvee can be lazy too. With the engine off, throttle valves can appear to behave correctly. But once under hydraulic pressure and the subsequent vibrations, can hang up too in their bores. Remember, they arecacting upon much softer aluminum sleeves, so anything that is off square in the bore can be a headache. I wish I was there to crack the code on this one.
...all work together for a shift. If a valve is a little stuck or cocked, the whole process gets thrown out the window. I am far away but really trying to think this one through. The answer has to be right in front of us. Stupid valve body! What a total brat.
It has to be a reluctant valve in the valve body. Again from everything you have described, one of them is causing a fault. Remember, the governor works in sequence with the other valves. If you look at the schematics (you will see when I pm you one from my book) it will be clear how all the hydraulic circuits work together. Line pressure, gov pressure, throttle oressure...
Any good mechanic will tell you this transmission is has Milage on it can be a lot of things starting to fail... Yes it's going to have to be rebuilt from the ground up....
The prob is a sticking valve as it returned to normal a few weeks ago, so while it seems like a big problem, it's a hidden little flaw, I will find it!
+CORVAIRWILD did you ever find out what the problem was?...My 85 GMC 700R4 started out fine then no second gear, it jumps from 1st to drive ...then later on overdrive stops working after the transmission fluid warms up....
find a forum for your truck that has threads on diagnosing that trans.
I know this is a old thread but first thing or few things would be TV detent cable adjustment, then governor by taking the pin out and valve and gear off cleaning it check to make sure the valve is moving up and down probably, then the fluid levels and filter.
Everything old is new again!
I tried everything to get that tranny to shift, new valve body, governor etc. it's still lying in the same place, one day I'll open it up. The Torque Convertor is seized on, pia
I cant find anything on why my 700r4 wont shift in my 4x4. Everyonce in awhile if i take off in low and get to about 25 mph it will go in second and get to about 40 mph it wont do anything else
Oblivion_Army I took off my valve body so many times to correct my non shifting problem. I put a new throttle valve cable, a new spring, I cleaned the valve body, I rebuilt the valve body, put a new valve body on, and nothing worked. I eventually changed the transmission, and I never opened it up to see what failed.
check the line pressure on the trans , google it , there are ports to install a gauge , it sounds like the pressure is down , and comes back from time to time when it works right , their is a pressure relief valve just like in the engine oil pump , I am sure you have seen an engine oil pump get a piece of valve seal in the relief valve before , you might have a small piece of clutch facing causing all of this ...
Good point, I'm almost ready to buy a reman valve body, but didn't think that was the prob. Is the relief valve in the pump pressure valve? I'm familiar with modifying the valve for a shift kit
CORVAIRWILD it is in the bottom of the front pump , you can see it with the pan off , it has a c-clip that holds it in , it is string loaded , there are 5 parts in there , from the clip in , you will find ... the clip , the boost valve and sleeve , spring , and the valve rod , there are a few o-rings on these parts , I bet it's junk in there , or a hard or broken ring , some times they don't want to come out , their is an easy way to get it out , you have to remove the c-clip , rreinstall the filter and pan , add a couple quarts of fluid , start it , and put it in reverse , you will hear it leave the pump as it pops it out , don't let the wheels turn , and shut down right afterwards , I have had this issue more than once ;) there are only 3 things that can cause this issue really , one is this pressure reg valve , the other two are governor , and the TV cable , by the way , set that cable back correctly , a loose cable will trash that trans , note the TV cable being set anywhere will still let it shift , as the governor will take control when it gets to high RPM's , and that is what leads me to the pressure reg , as it has to have pressure to apply the clutches and make the shift , without pressure the throttle valve , or the governor neither even if working right will make the shift , they are making the call , but the pressure is not there to make the shift ... so how many of these transmissions have I broken , well you don't have enough trucks cars , and trailers to haul them , I killed 1 or 2 a week for years being young and dumb , ever wore out the threads in an engine block bellhousing ha ha ha I have lol
towrecker
I didn't hear from the tranny place, I'll try him again tmrw. So is the boost valve the prob GM had with excessive wear as it is always moving, and wears the bore?
CORVAIRWILD yup and they always buzzed too from time to time , the boost valve is on the passenger side of the teeruk beside the hole the filter plugs into , and the pressure reg is on the drivers side , checking both might be worth the time too
towrecker
Vid soon...
those drain plugs suck, welded the hole up in two of my pans, nothing but leaking junk. Btw parts washer, can make them out of old dish washer, beats paying for brake clean. brake is for one thing, cleaning drums and rotors of dirt and grease imo.
Could also be your vacuum modulator
Lesson 1 drain pan see how much metal is in the pan. If it looks good not much metal change the filter clean pan with brake clean . Clean silicone off Governor cover brake clean it too. Governor valve hold it and press both butterflies to see if valve is moving up & down . If the valve don't move take out roll pin & clean valve sleeve. if that valve is stuck Transmission will not up shift it will start off in 2nd gear . Do not use silicone on pan just a small bead around Governor cover. Use Cork pan gasket for pan not the black crappy one that comes with a filter kit ? Go over each hole on the pan where the bolts go thru & Hammer down them flat with a punch or ball peen hammer . Put new cork gasket torque bolts down. Put 4 liters in transmission start it up Check fluid . Jump in put it in reverse check fluid again . Let it warm up check fluid again ! Then when it's all level take it for a ride but drop it into 1st gear and shift Manual 1-2-3 drop it to 1st again 1-2-3 again same thing for 2 km . What this does is free up that Governor valve so it does not stick . If you put it in drive and it starts shifting normal again you did it right ! If it starts off in 2nd gear from a stop then pull governor gear out again free up valve or replace it !! Hope this helps !
luis freitas I tryed a different valve body and governor, nothing helped. I never disassembled the old tranny, the convertor is seized into the input shaft. One day...
Throttle valve cables and the throttle valves themselvee can be lazy too. With the engine off, throttle valves can appear to behave correctly. But once under hydraulic pressure and the subsequent vibrations, can hang up too in their bores. Remember, they arecacting upon much softer aluminum sleeves, so anything that is off square in the bore can be a headache. I wish I was there to crack the code on this one.
He sprayed half a can of brake cleaner directly into his transmission... If it wasn't broke before, it is now...
It WAS broken then, it's still broken, sitting on floor, same place 3 years
@@CORVAIRWILD LOL... sounds like some of my projects. LOL. I finally got around to building my S-10 Hot Rod after all most 20 years...
Upon removing the governor, did you have to drain a lot of transmission fluid? I would like to know bc I'm about to replace it when I get the time.
Aww, sorry he never responded lol. But no there is usually not a lot of fluid in there. maybe a half spoon to a spoon full.
@@Lilmiket1000 I got the kit but never changed it out haha ..thanks for the reply
Amen on the silicone brother he he don't use that on that transmission that's a No-No
it's the torque converter that is going bad
...all work together for a shift. If a valve is a little stuck or cocked, the whole process gets thrown out the window. I am far away but really trying to think this one through. The answer has to be right in front of us. Stupid valve body! What a total brat.
buenos días, disculpe no domino el ingles. causas q dañan el piñon del gobernador
A transmission rebuilt Price $1000- 6000 depending where you take it... This a a price for a transmission for you year Chevy suburban
Dude cover on drop valve body install cheater spring