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Hot Rods 700r4 pulling hard

Discussion in 'The Hokey Ass Message Board' started by crass, Jun 17, 2018.

  1. crass
    Joined: Jun 13, 2008
    Posts: 35

    crass
    Member

    So my 51 chevys original engine and trans were junk. I took the complete running gear out of a 79 el camino and swaped it in. 305 and 700r4 trans. Drives pretty nice now except for one problem, the car seems to shift hard from park into drive no matter what I set the idle to, when I'm rolling down the road and take my foot off the gas the car seems to just want to keep doing the speed I'm going kind of like cruse control. Idles down a little only when I hit the brake and when I come to a stop the car wants to creep hard unless I stand on the brake pedal. Even with the idle set really low it seems to behave the same. Since I did this swap a few years ago I crawled under the car and remembered I didn't hook up these wires on the driver side of the trans to anything. Actually I don't even know what they go to but I'm guessing that it's my problem or part of my problem. Are they the governor or vacuum modulator? Anyone know how I should have it hooked up. Any other advice on what to check. Thanks. governer.jpg
     
    chryslerfan55 likes this.
  2. No. 1, The 700 R4 came out in about 1982.
    No. 2, There is no modulator on a 700. The governor is a hydraulic valve.
    Hard to help, with incorrect and/or missing information.
     
  3. squirrel
    Joined: Sep 23, 2004
    Posts: 41,071

    squirrel
    Member

    The wires are for the torque converter lockup, which sounds like it's engaged...but it shouldn't be, since the wires are not connected!

    What is the engine idle speed?
     
  4. crass
    Joined: Jun 13, 2008
    Posts: 35

    crass
    Member

    I thought this was a 700r4 but I could be wrong. All I know is I pulled it out of a 79 g body type el camino with a 305. I guess it might be a 700 then because it is longer then a 350 or 450 trans and looks like a 700r4 to me. I believe this was the original trans that was in the el camino. I was thinking something along the lines of the torque converter lockup being engaged also. idle is at normal rpms 500 - 700 range. It pulls even harder if the idle is set high and still pulls hard when the idle is way low like about to stall.
     
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  5. Show us a picture of the oil pan. If the converter is staying in lock up with no wires hooked up it would be the second one in two weeks here supposedly. What are the odds?
     
  6. squirrel
    Joined: Sep 23, 2004
    Posts: 41,071

    squirrel
    Member

    what shape is the pan? that should get you started on identifying it. 700R4 is mostly rectangular. 350 is square with a corner cut off. 400 is odd looking.
     
  7. big duece
    Joined: Jul 28, 2008
    Posts: 5,193

    big duece
    Member
    from kansas

    Looks like a 700r4 pan to me.
     
  8. big duece
    Joined: Jul 28, 2008
    Posts: 5,193

    big duece
    Member
    from kansas

    Is there a large vacuum leak, is the carb stuck on fast idle?
     
  9. Happydaze
    Joined: Aug 21, 2009
    Posts: 665

    Happydaze
    ALLIANCE MEMBER

    I've had exactly the same symptoms problem. An increased stall speed converter fixed it instantly and driveability and seat of the pant performance improved dramatically. It think it's to do with taking the engine / trans combo from a vehicle that was much heavier than the application it became installed in.

    Chris
     
  10. choppedtudor
    Joined: Nov 28, 2009
    Posts: 639

    choppedtudor
    Member

    I have a 700r4, and it sounds like you either have the wrong torque converter in there, or it has failed...is your TV cable set-up properly??? the 700r4 does NOT use a "kick-down" cable like most other trannies...
     
  11. old chevy luver
    Joined: Aug 7, 2013
    Posts: 42

    old chevy luver
    Member
    from sd

    700r4 has the same governor as 350 or 400. The modulator is the t.v. Cable. Do u have a t.v. Cable on it adjust correctly? If it is 700r4 the t.v cable has to be hooked up, and adjusted correctly and hook to the carb at the right distance from center of carb shaft.To adjust there should be a half circle with a tin plate. Push down on tin plate and the spring on the cable should push the cable housing back. Now with engine off, step on throttle pedal till on the floor(wide open) and should hear the cable ratchet forward and its set. The700r4 built before 87 has no accumulator for p to 1st to cushion shift ,so they shift hard on idle above 500 rpm. The first yr for 7oor4 was 1982. Has the motor and tranny been changed or u off on the year.? 700r4 has 16 bolts on the pan. And pan has just 4 corners. On the right hand (pass) side towards the rear of where the pan bolts up is a tag. If the 1st number on the tag is, 3,4,5,6,or 9 it's pre 87. The wires r for converter clutch. If is a early tranny, there would of been a vacuum line going to a switch and brake switch. So if u didn't transfer to your car, you have a open vacuum port somewhere. Check for vacuum leak. U could have a stuck conv clutch solenoid. Pull the pan. At the front of the tranny there is two bolts holding the solenoid on. it's between the hole for the filter and dipstick. Remove bolts and pull it straight down.It should have 2wires. Connect 12v from battery to red wire and ground to black wire, it should click and hold air if u blow on the end. Unhook it and should open and u should be able to blow through it easily. If it clicks and works, clean any dirt on the solenoid on in the hole. Put it back on and install pan fill to correct level (about 4qts ) put three in start motor put in gear then in park let motor run check oil add till at correct level (don't over fill). Try it.


    Sent from my iPhone using The H.A.M.B. mobile app
     
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  12. indyjps
    Joined: Feb 21, 2007
    Posts: 3,522

    indyjps
    Member

    Most G bodies, elcamino is same frame, used 200-4r. Please take a look underneath at the pan. Not sure what your wires are yet. Screenshot_20180618-090032_Chrome.jpg
     
  13. blowby
    Joined: Dec 27, 2012
    Posts: 5,348

    blowby
    Member
    from Nicasio Ca

    Yep, I would pull the pan and lock up solenoid. If that's not stuck you may have to pull the converter.
     
  14. crass
    Joined: Jun 13, 2008
    Posts: 35

    crass
    Member

    Here's a few more pictures looks like a 700r4 to me. I did however find this tag on the side of the trans so I think it may have just been installed in the el camino at a later date sometime. image2.jpeg image3.jpeg image1(2).jpeg


    I was also thinking something like that, do you mean on the carb? I don't see any vacuum lines going to the trans but maybe I'm not looking in the right spot. Here's my carb setup it's an edelbrock 1406, left port is just taped up I should probably plug it up better. Middle port goes to my valve cover and the right port goes to my vacuum advance. I believe this is the proper way to have it setup. I believe my TV cable was setup properly I did just brake the plastic piece that connects it yesterday.

    IMG_2993.JPG IMG_2994.JPG

    I was also thinking something like this could be a possibility but was not sure but am leaning towards that as being the problem. I drove the el camino home and around the block twice before pulling it apart but I don't remember it having this problem in the el camino. I feel like the 51 chevy is a much lighter car then the el camino. I just did some checking and I'm seeing weight specs at around 3300 - 3500 lbs for the 51. Weight specs on a 79 el camino are around 4400 - 4900 lbs. I guess if all else fails I can try a increased stall speed converter. Anyone know what would be a better option converter?
     
  15. squirrel
    Joined: Sep 23, 2004
    Posts: 41,071

    squirrel
    Member

    The weight you list for the el camino is probably GVW, which is loaded weight. The two cars are not that far different in weight, that it would be an issue.

    No vacuum lines go to that transmission. The vacuum leak he is referring to would be something like a leaking carb base gasket, leaking intake gasket, bad power brake booster, cracked or disconnected vacuum hose, or similar.

    The broken TV cable is something you need to fix before you try to drive it again. But I really doubt it has anything to do with the torque converter issue (if that's what it is).
     
    Truckdoctor Andy likes this.
  16. Right.
    Not even close on the actual weight. I'll bet it's within 300 # ..Not an issue . Was it an issue three years ago? Was it pulling hard 3 years ago?
    Not buying the converter going to lock up ,with NO electrical hookup. ..So you hit a bump and it went into lock up?
    As soon as you came to a stop and it didn't stall the engine , it 's out. What are the odds it happens every time? Zilch.
    The way I see this, my friend , is, and this goes for several other similar threads recently, you have a used transmission that you've been running for several years,...you haven't even looked inside the pan, but you want someone here to diagnose it, and give you an estimate on the repair.

    Let's see...Nothing yet


    45.jpg

    ;-)
     
  17. pprather
    Joined: Jan 10, 2007
    Posts: 871

    pprather
    Member

    That taped up vacuum port on the carb needs a better seal. The problem will probably have several parts to the fix.


    Phil
     
  18. crass
    Joined: Jun 13, 2008
    Posts: 35

    crass
    Member


    In my last post I said I don't remember having this problem before I pulled the engine and trans out of the el camino. I don't need someone to give me an estimate on a repair I just want to be pointed in the right direction. This is a confusing problem for me and I'm wondering if anyone else has went through a similar situation. Now some say vacuum, stuck in fast idle, locked up converter, bad converter, TV cable, lighter car, at least this give me a few things to check.

    The strange part to me is when I'm up to speed and take my foot off the gas the car just cruses like it's in cruse control, doesn't want to slow down unless I hit the brakes. Feels like it will be extremely hard on my brake pads if I don't fix it.

    I did this swap then drove the car for maybe a few hundred miles and packed it away for a few years, now I'm ready to finish it up. I think that is the gross weight for an el camino. For some reason I feel like the chevy is somewhat lighter but I could be wrong. It is a convertible that's half rusted and stripped down. There has to be some weight difference. I am wondering how much of a difference in weight would start to cause a problem. I think maybe checking the vacuum and fast idle will be where I'm going to start otherwise.
     
  19. pprather
    Joined: Jan 10, 2007
    Posts: 871

    pprather
    Member

    Good start!


    Phil
     
  20. saltflats
    Joined: Aug 14, 2007
    Posts: 8,853

    saltflats
    Member
    from Missouri

    Sounds to me like it is not shifting into O/D.
    I would pull the pan and look for a bunch of black stuff.
     
  21. Again, the weight difference is negligible.
    Better question..What is your current rear end ratio, vs. the Elky? What did the rear come out of?
    Let's see if we can diagnose this issue.
    So, you're cruising down the road at 45 mph, 4 th gear, and it acts like it's on c/c. You throw it into neutral.What does the rpm go to?
    Same scenario...4th gear..You put the shifter into 3rd gear. What happens ?
     
  22. crass
    Joined: Jun 13, 2008
    Posts: 35

    crass
    Member


    Never tried putting it in neutral when rolling that speed but I will see what happens and report back. It's an automatic shifting to low or 2nd at those speeds from drive causes the rpms to increase I believe but I will try again and verify. The rear end is out of the el camino also there should be no issues there.
     
  23. big duece
    Joined: Jul 28, 2008
    Posts: 5,193

    big duece
    Member
    from kansas

    My wifes OT firechicken 305 Q-jet had the brake booster fitting clocked wrong, and one of the hex points was keeping the rear of the carb from sealing properly. Huge vacuum leak. Idled around 1k, could not lower it with idle screw or mixture screws. Took a bit to find it. In a hurry, the simplest things can get overlooked.
     
  24. crass
    Joined: Jun 13, 2008
    Posts: 35

    crass
    Member

    Just for fun, this is the car I started with

    IMG_0406.jpg

    This is the el camino I destroyed

    IMG_0636.JPG

    And this is what I ended up with

    IMG_2869.JPG
    IMG_2875.JPG
     
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  25. gimpyshotrods
    Joined: May 20, 2009
    Posts: 15,563

    gimpyshotrods
    Member

    DO NOT, I REPEAT, DO NOT drive it anywhere, at all, even a little, with the Throttle Valve cable disconnected.

    Get that cable end fixed, or replace the whole cable, first, then buy a set of vacuum line caps, and cap all unused lines/ports.
     
    31Vicky with a hemi likes this.
  26. 1930 A
    Joined: Apr 8, 2006
    Posts: 125

    1930 A
    Member

    if the convertor clutch were stuck on the engine would stall when you stopped just like if you had a standard transmission and didn't push the clutch pedal in.
     
    squirrel likes this.
  27. image.jpeg
    Love it mark yac!!!
    The crystal ball consultation is far better than a WAG right?

    Sounds like it might be more than one problem.
    Ok so, there's no modulator on this Trans, but the high line pressure symptoms are that of a defective or disconnected modulator. And the TV cable is not connected and the trams hasn't self destructed yet- SOOO What are the chances the TV arm is stuck or cable remnants pulled tight ? If so That would show the same high line pressure symptoms AND explain the Trans still being operational. Getting the cable adjustment wrong can blow a 700r4 Trans just going around the block.

    Personally I would not drive it anymore until that cable was fully operational and I stand firm with what gimpy said here.
     
    theHIGHLANDER and VANDENPLAS like this.
  28. VANDENPLAS
    Joined: Dec 14, 2009
    Posts: 1,385

    VANDENPLAS
    Member

    Your engine from what you say is ideling correctly.
    The tv cable disconnected can be your issue, it’s connected to a little box with a bell crank type connection in the corner of the trans, real easy to get stuck if your not careful.

    I’m suspecting high line pressure, pull the pan and have a look if there’s excessive debris and metal in the bottom
    Black gunk is ok-ish metal is not.

    This could have been there and you never noticed before, stiffer springs in the valve body, missing or lighter check balls etc.

    Pull the pan, make sure the tv valve is not stuck on, if your confident
    Drop the valve body and check you don’t have a stuck valve and all check balls are in place.
    Chevy used steel and plastic balls, different weight with different characteristics.

    A stuck Tcc would cause a stall when stopping
     
    31Vicky with a hemi likes this.
  29. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 7,517

    theHIGHLANDER
    Member

    I don't want to make light of the issue (well not too much at least), but the crystal ball thing is funny as fuck!

    I've had folks want a price on body work or restoration over the phone. When told I have to see it 1st and they resist it goes;
    "Are you on a cell or cordless phone?"
    'Yes, I am'
    "Maybe if you get closer to the car it'll be easier"
    It's hang up time when they say 'Ok, wait a minute...'

    Back on topic, all of the symptoms scream vacuum leak to me.
     
    big duece likes this.
  30. BJR
    Joined: Mar 11, 2005
    Posts: 4,910

    BJR
    Member

    You painted a rusted out car yellow without fixing the rust or dents? Are you building a 50's RatR?
     
    flynbrian48, bobss396 and Blue One like this.

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