1982 700R4 help no OD

[1983_SB_4X4]

New to the forum & really need some knowledge here. I just purchased an '83 K10 & it has the 700R4 trans. I've been around SBC's my whole life but I've never messed with an OD transmission. So I need a little help understanding how this trans works. The tranny goes through 1st, 2nd & 3rd gear but will not lock up the OD for some reason???? If I take off with very little skinny pedal it shifts from 1st to 2nd then quickly shifts to 3rd. If I put a lil weight on the skinny pedal it will stick in 1st all the way up to 4500 rpm until I lift the excelerator then & only then will it shift. I've read where folks say this is govenor related but before I tear into anything I would like some input. If the govenor is bad would it prevent the torque converter from locking up & going into OD??? Thanks in advance, and yes fluid levels are fine both hot & cold & fluid is clean & does not smelled burned.

Rob

 

[Jims86]

New to the forum & really need some knowledge here. I just purchased an '83 K10 & it has the 700R4 trans. I've been around SBC's my whole life but I've never messed with an OD transmission. So I need a little help understanding how this trans works. The tranny goes through 1st, 2nd & 3rd gear but will not lock up the OD for some reason???? If I take off with very little skinny pedal it shifts from 1st to 2nd then quickly shifts to 3rd. If I put a lil weight on the skinny pedal it will stick in 1st all the way up to 4500 rpm until I lift the excelerator then & only then will it shift. I've read where folks say this is govenor related but before I tear into anything I would like some input. If the govenor is bad would it prevent the torque converter from locking up & going into OD??? Thanks in advance, and yes fluid levels are fine both hot & cold & fluid is clean & does not smelled burned.

Rob

Welcom to GMSB,
There is a connector on the drivers side of the transmission, make sure thats connected.
You should also have a brake switch unfer the dash, with that same wire, make sure thats connected securely, and is adjusted properly, this disconnects power fro lockup when you hi the brakes.
Under the hood, on the firewall, ther should be a vacuum switch, with 2 wires, on comming from key power, and one going to the brake switch. trurn the key on, and confirm that your getting 12 volts on one of those wires.
while your at it, amke sure that the vacuum line is going to a thermal vac switch on the intake manifold, and also make sure the switch is connected to a manifold vacuum source.
If this all checks out, powered, and connected, and still no worky, i would get a 12 volt switch, like from a set of fog lights, and a couple of lengths of wire, wire one end to the 12 volt side of the vacuum switch, and the other side to the wire in the brake switch plug, going to the transmission. then drive the truck, let it get to around 40 mph, and flip the switch, and see if you notice lockup, if so, tha vacuum switch needs to be replaced. if not, then the next step would be to open the trans pan, and replace the TCC lockup solenoid, its right behind the bellhousing, in the valve body, held in with 2 bolts. replace the trans filter while your at it. and if that doesent work, either you have a bad clutch in the torque converter and/or 4th gear is totally gone.
A lot of work, yes, but you can save gobbs of money by doing these steps yourself. if it turns out that the trans is bad, I would recommend going to the wrecking yard, or craigslist, and find an 88-92 700r4(some refer to it as the 4l60) and have it rebuilt at a good shop, who should be able to do a good rebuild, with a new converter for around $700. Its a way better unit than the earlier ones.

 

[1983_SB_4X4]

Jim,


Thank you very much for the response. please see below in red, and thanks for the welcome......

Welcom to GMSB,
There is a connector on the drivers side of the transmission, make sure thats connected.4 pin plug with 3 wires is in tact, and connected. 1-Yellow wire, 1-Blue wire and 1- Green wire
You should also have a brake switch unfer the dash Brake pedal has 2- switches on it. One controls my Brake lights (orange & white wire) the other I assume is to the Torque Converter (1-Gray wire & 1- Blue wire I think??) Wires do not look the same guage or color as the ones coming from the plug on the tranny though...., with that same wire, make sure thats connected securely, and is adjusted properly Not sure what the propper adjustment is on this, but I put a test light to it, and when the brake pedal is depressed the Gray wire looses power. When the brake is in the unpressed position it has power. So once again looks like all of this is functioning properly???, this disconnects power fro lockup when you hi the brakes.
Under the hood, on the firewall, ther should be a vacuum switch, Found this also it is over near the heater/AC box. Have not checked it for 12V yet but I did replace the Vaccum line that went to the back of the Intake Manifold.....with 2 wires, on comming from key power, and one going to the brake switch. trurn the key on, and confirm that your getting 12 volts on one of those wires. I need to confirm this.
while your at it, amke sure that the vacuum line is going to a thermal vac switch on the intake manifold, and also make sure the switch is connected to a manifold vacuum source. Not sure what a thermal vaccum switch is?? It was connected directly to the intake manifold
If this all checks out, powered, and connected, and still no worky, i would get a 12 volt switch, like from a set of fog lights, and a couple of lengths of wire, wire one end to the 12 volt side of the vacuum switch, and the other side to the wire in the brake switch plug, going to the transmission. then drive the truck, let it get to around 40 mph, and flip the switch, and see if you notice lockup, if so, tha vacuum switch needs to be replaced. if not, then the next step would be to open the trans pan, and replace the TCC lockup solenoid, its right behind the bellhousing, in the valve body, held in with 2 bolts. replace the trans filter while your at it. and if that doesent work, either you have a bad clutch in the torque converter and/or 4th gear is totally gone.
A lot of work, yes, but you can save gobbs of money by doing these steps yourself. if it turns out that the trans is bad, I would recommend going to the wrecking yard, or craigslist, and find an 88-92 700r4(some refer to it as the 4l60) and have it rebuilt at a good shop, who should be able to do a good rebuild, with a new converter for around $700. Its a way better unit than the earlier ones.

Once again thank you very much for the reply. I hope I can get this thing fixed. I REALLY look forward to keeping this ole truck on the road, and driving it daily. Rite now the relationship between it and my pocket book is not a good one at the gas pump. Running 2500 RPM @ 62 MPH is not easy on the wallet. I drive over 100 miles to, and from work each day and it's not cheap!!


Rob

 

[Jims86]

Jim,


Thank you very much for the response. please see below in red, and thanks for the welcome......

Once again thank you very much for the reply. I hope I can get this thing fixed. I REALLY look forward to keeping this ole truck on the road, and driving it daily. Rite now the relationship between it and my pocket book is not a good one at the gas pump. Running 2500 RPM @ 62 MPH is not easy on the wallet. I drive over 100 miles to, and from work each day and it's not cheap!!


Rob

I looked in my manual for wire colors, but they are not listed. I would have a friend sit in the drivers seat, and have them push the brake pedal while you probe that trans connector for the lockup wire...I thought the pre 85 700r4s had only one wire, but i may be getting that mixed up with the 400.
a thermal vacuum switch is usually screwed into the cooling passage on the intake, or up in the thermostat housing...it just turns the vacuum on and off, depending on engine temp.
Its probably a benifit if its going directly to the manifold..at least that should give you lockup regardless of coolant temp...no biggy.
Sounds like your brake switch is working fine, it and your brake light switch ratchet back and forth in the brackets for adjustment.
i will dig a little deeper to see if i can find out what those other wires in the trans connector do, I am curiouse.

 

[1983_SB_4X4]

Jim the more I think about it, I think from what I've read there is a 2/4 servo in the tranny?? If that's the case I think that servo is not working. I put a tach on it yesterday and it seems like its shifting from 1st to 2nd briefly then sliding smoothly into 3rd. I manually ran it through the gears with the shifter & 2nd doesn't want to grab. But if I go from 1 to 3 on the selector it seems to go through 2nd real quick into 3rd.

 

[Jims86]

Jim the more I think about it, I think from what I've read there is a 2/4 servo in the tranny?? If that's the case I think that servo is not working. I put a tach on it yesterday and it seems like its shifting from 1st to 2nd briefly then sliding smoothly into 3rd. I manually ran it through the gears with the shifter & 2nd doesn't want to grab. But if I go from 1 to 3 on the selector it seems to go through 2nd real quick into 3rd.

hmmm...the only thing I can suggest is a good flush, and lots of prayer. a trans shop could do a hot flush, but it does not sound too promising at this point.

 

[oneluckypops]

FYI Lock up is NOT 4th gear. Lock up should be acheived around 40-45 mph with steady engine load.

2-4 servo is defintly something your gonna want to look into, But dont rule out the govenor either.

HRPC is very knoledgeable when it comes to alot of things and Transmissions is 1 of them, hopefully he will chime in here 1 of these days or you might send him a PM to get his attention.

Wish I could be more help but I am afraid your Transmission is not an electronic one so I will just watch and maybe learn

 

[Jims86]

FYI Lock up is NOT 4th gear. Lock up should be acheived around 40-45 mph with steady engine load.

2-4 servo is defintly something your gonna want to look into, But dont rule out the govenor either.

HRPC is very knoledgeable when it comes to alot of things and Transmissions is 1 of them, hopefully he will chime in here 1 of these days or you might send him a PM to get his attention.

Wish I could be more help but I am afraid your Transmission is not an electronic one so I will just watch and maybe learn

Yup, correct, take into consideration, that his tranny IS shifting. Some 700r4s (later models)even lock up in 3rd. Im thinking that his 2 and 4 clutchpacks may be gone...which is normal in these transmissions.....I have had 5 of them.
I may be looking into upgrading to an early 4l60e built up with 4l65e parts and change to the later 94-95 TBI ECM.

 

[oneluckypops]

Yup, correct, take into consideration, that his tranny IS shifting. Some 700r4s (later models)even lock up in 3rd. Im thinking that his 2 and 4 clutchpacks may be gone...which is normal in these transmissions.....I have had 5 of them.
I may be looking into upgrading to an early 4l60e built up with 4l65e parts and change to the later 94-95 TBI ECM.

better decide which ecm and which Transmission you want cause 95 is a year of its own, course you can program for either huh lucky ass lol

 

[Jims86]

better decide which ecm and which Transmission you want cause 95 is a year of its own, course you can program for either huh lucky ass lol

They started using the 7427 ecm out here in 94, along with the first generation of 4l60e....95 is the same.

 

[oneluckypops]

They started using the 7427 ecm out here in 94, along with the first generation of 4l60e....95 is the same.

you mean 95 is the same ECM right? with the exception of the programming, 95 was first year for PWM

 

[J oops]

If govenor was out it would not shift out of 1st or for that matter make it to third. The 2-4 band is going out.

 

[adamv7010]

Im having the same issue on my 82 suburban ...alot of tines when these are rebuilt there's a drum guys don't replace for whatever reason ...probably cost..but mine was reused and I loose od part of the time.

 

[1983_SB_4X4]

Found a good used '91 unit out of a 4x4 for $150. Hope I can get the money together by Friday. Who needs parts??? I got a few square parts!!!

 

[89Suburban]

Found a good used '91 unit out of a 4x4 for $150. Hope I can get the money together by Friday. Who needs parts??? I got a few square parts!!!

Good, keep the old one to rebuild yourself. There are threads here on it.