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Hot Rods 700r4 pulling hard

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

  1. That's what we use now, Vick,..when the o/p doesn't want to pull the pan and take a look.
    As stated, the TV valve could be sticking and all gunked up...among many other maladies.
    Love the entertainment here though.
     
    hidez57 likes this.
  2. Ken Boellner
    Joined: Dec 21, 2017
    Posts: 10

    Ken Boellner

    I think you have a 350c with lockup converter. Thats what I had in my Elcamino.
     
  3. crass
    Joined: Jun 13, 2008
    Posts: 35

    crass
    Member

    Yeah, in my post I said the TV plastic piece just broke it was adjusted properly I believe. I'm going to fix it before testing it again. I'm not driving it around like that. But I will pull the pan also and see what it looks like inside here shortly.

    Yeah, so what. I don't understand why everyone whats shiny and new. Still working on it. It's not done yet for sure.
     
    craig b blue likes this.
  4. MAD MIKE
    Joined: Aug 1, 2009
    Posts: 489

    MAD MIKE
    Member
    from 94577

    Nope. It's a 700. 5 bolts at the back of the pan, that goofy crinkly pan, and the lockup is vertical rather than horizontal.

    Need to get back to basics if the engine is pulling or has higher than expected revs at idle.
    Verify the base timing is not too far advanced, pull the vac advance and recheck base timing after the engine has warmed up(choke off/open).
    Verify there are no vacuum leaks around the intake gaskets and plenum.
    Properly seal off any unused ports with proper vacuum caps.
    Replace any vacuum hoses that are more than five years old, same for vacuum caps.
    If the engine is running normal recheck the transmission.

    T.V.(throttle valve) cable replaces the vacuum modulator and kickdown on the TH200; TH200C; TH200 4R; and TH700 R4/4L60. It is critical that this is properly adjusted. In factory applications the cable is normally adjusted via unlocking the adjuster pulling back the cable housing locking it. Then using the pedal to floor the throttle and it will self adjust. However older/worn adjusters may not allow the correct tension/adjustment. And custom mounted cables may also might not have the correct geometry/adjustment.
    Ideally you would have a transmission pressure gauge hooked up to the pressure port and check pressure in gear.
    Idle @ 1000rpm, apply brakes.
    Neutral - 55-75PSI
    D1/D2 - 85-190PSI
    Drive - 55-75PSI
    Reverse - 85-140PSI

    T.C.C.(Torque Converter Clutch) needs to be activated when in 4th gear, otherwise you can burn up 4th gear(overdrive) and overheat the transmission fluid without the trans locked up. If the original gear set is in the differential, this is even more so important as the factory ratios on this generation Elco were in the 2.14-2.79 range. With OD that puts it into 1.5-1.95 final drive for the engine.
    If you cannot get to the TCC wiring, just don't drive the trans in OD(4th) 1-3 should be fine for now.
    TCC can be hooked up with a simple switched power source and interrupted with a brake switch to drop TCC out of lockup when coming to a stop. TCC does not lockup in 1st.
    However since the trans has been rebuilt, it may have been modified to work 4th without lockup.
    I would call the transmission shop on the tag and see if they have any record using that serial number.

    Now if everything checks out, I'm guessing your brakes may not be properly working.
    It appears you have subbed on the Elcos front suspension.
    How much of the Elcos brake system did you use? The combination valve used a metering valve that needs to be held open when normally bleeding. It's a button that needs to be pulled open, there is a special spring tool that is used to hold it open. Otherwise it may be difficult to properly bleed the fronts. Also if the car is slowing but not completely stopping as expected, go for a drive around town. Make sure the brakes are getting well used. Hop out of the car and place your hand near the brakes. If the fronts or rear feel cold then they may not be functioning.

    As for the sudden bang into gear, I've owned two Th700s one in an '84 Sierra the other in a '92 S-10. Both shifted into gear pretty harshly. Replaced rubber mounts and rear shocks on the '84. This helped a bit but it still shifted into gear pretty tough. Cold mornings in a rush, the whole bed would shudder. On the '92 I replaced the engine and trans mounts with poly and the rear shocks with Bilsteins. It was much better when shifting into gear, it didn't feel like the driveshaft was whipping, but it felt as though you were leaning against the converter. RPM was fine, pressure was fine. I just attributed it to the 700s characteristics. I would wait til the engines warmed up and kicked down a bit before shifting into gear.

    Only thing I could come up with was that the combination of the TC multiplication and the 3.08 1st gear were what was causing the added thump into gear. 20% more torque multiplication from the lower first gear probably is part of the issue.
     
  5. Yes, the 3 speed , late 70's cars used ridiculously high rear end ratios.
    That makes me wonder why a later 700 was transplanted into the Elky in the first place.
    The gear ratio must have been changed at that time. Maybe the o/p could tell us what ratio is in there at this time.
     
  6. crass
    Joined: Jun 13, 2008
    Posts: 35

    crass
    Member

    Ok, so this is where I am at. I replaced the broken detent on the TV cable and set the TV cable, put vacuum caps on all 3 ports on the front of the carb, checked the timing again seemed ok maybe a little high around 9 to 11 I set it down to around 6 to help it idle down a little more. Found that the electric choke power wire was not getting power so I fixed that. Plugged up all 3 vacuum ports on the front and the one on the back going to the brake booster to try and eliminate any vacuum problems and still no luck. When I shift into gear from park it sometimes pulls so hard it spins the rear tires on my gravel driveway. I am unsure of the rear end ratio I haven't opened the rear up yet but just guessing it is probably the stock rear end. So I pulled the pan on the trans and found black stuff mixed with what looks like metal dust.
    image1(3).jpeg

    I am unsure if this is normal wear for an old transmission or if something has failed. I don't really see any chunks of metal bits or hear anything grinding in the trans it is mostly just dust looking. So with the pan off I don't really have any idea what I'm looking at or for inside the trans as this is not really my area of expertise, but I found it interesting that the wires going into my transmission are not hooked to anything..

    image2(2).jpeg

    So just from looking at some pictures online of some other 700 transmissions it looks like I'm missing all the wiring inside the trans.. someone has taken it all out for some reason or it has been modified in some way. Another poster mentioned to check for a stuck clutch solenoid, so I looked and it has had the wires cut off it.. I pulled it out and it is definitely stuck closed, I tried blowing on it and it is plugged up solid. Stuck a nail in there and cleaned out what looks like more metal dust, almost looks like jb weld when it's wet.

    image3(1).jpeg
    image4.jpeg

    So I'm not really sure whats going on here. If the trans was modified in some way to work differently or what. Anyone have any ideas of what to do or check next or what the hell is going on here?
     
  7. I've seen worse in the pan, but the gunk in the solenoid would concern me. We'd still be guessing here, to speculate about what's been done in the past. At this point, we don't even know if you've even got a lock up clutch in the converter. Non stock application, local rebuild..No telling.
    I know you don't want to hear this, but it's that time.:(
     
  8. fergusonic
    Joined: Nov 11, 2007
    Posts: 220

    fergusonic
    Member
    from Kokomo, In

    also will need a TV cable corrector brkt on the carb. p/n 376710
     
  9. I agree,
    I'd also like to know how this could have possible worked in the elcamino.

    Anyways it's something different now.
    A Trans mechanic is going to be able to give you the best ideas why someone might have done what you're seeing. I just think too much.
     
  10. MAD MIKE
    Joined: Aug 1, 2009
    Posts: 489

    MAD MIKE
    Member
    from 94577

    Then your rear brakes are not working. This would also cause the pushing you are feeling when you try to stop your car. Rear brakes may only do 30% of the braking, but that 30% includes slowing/stopping the drivetrain.
    Looks like it's been quite a while since it has been changed. As long as it doesn't smell burnt you should be fine.
    That gunk on the solenoid is typical buildup found in high mileage transmissions, usually it builds up in areas that don't readily flush out. Since the solenoid is non-functional the gunk can just buildup.

    Th700 R4s and Th200 4Rs can be modified to use a more conventional high stall converter without lockup function. That would explain the non functioning TCC solenoid. Normally that solenoid has a pig tail that plugs into the back of the plug that passes through the transmission case. But the solenoid needs to be left in place to prevent an internal leak.

    I would call that tag on the transmission give them the serial number and see how the transmission was built. There are ways to build 700 trans without needing a lockup converter. A lockup GM converter will have flats on the engine side.
     
  11. David Gersic
    Joined: Feb 15, 2015
    Posts: 2,164

    David Gersic
    Member
    from DeKalb, IL

    What “works” is subjective. When I looked at my 37, the guy I bought it from was manual shifting the 700r4 with a Lokar nostalgia shifter. He’d hold it in gear to 5-6000 RPM, then move the stick to let it up-shift. “Worked” for him...

    I’m in a similar boat to the OP here. Unknown junkyard 700r4 rebuilt several times by unknown shops and one community college class. Unknown “shift kit” installed. Unknown other modifications. I’ve corrected some of these, but it’s still not right.

    There are some simple things you can do and check.

    On the carb, is the TV cable geometry correct? If not, a correction kit is cheap and easy to bolt on. You MUST have a working TV cable, correctly adjusted, or the trans will die quickly, like by the end of the first block.

    With the pan off, you can double check that the TV plunger is fully buried at WOT. Do that while you can get to it easily.

    The hacked up solenoid you can toss in the trash and replace. At the top of the hole that the solenoid goes in, there is a hole. Stick a pick or screwdriver in there and push up. You should feel a spring loaded plunger. You’ll need the rest of the wiring harness in there, TCI is one source for parts to fix this up.

    I read somewhere that there are differences in the 700r4. Early ones shift hard from P to 1. Later ones were upgraded to make the P to 1 shift less bang-y. You may have an early one.



    Sent from my iPad using The H.A.M.B. mobile app
     
  12. David Gersic
    Joined: Feb 15, 2015
    Posts: 2,164

    David Gersic
    Member
    from DeKalb, IL

    Guessing, lockup function disabled. Look at the torque converter. Does it have one flat side, one rounded? Or both sides rounded?



    Sent from my iPad using The H.A.M.B. mobile app
     
  13. David , The cover won't tell you a thing. All converters for the 700 (and 200 4r ) are built using the same metric pieces that stack up to the correct overall height. Don't want a lock up clutch in yours? You just slip the clutch off the spline on the back of the turbine, and put it together without it. It's going to look exactly the same on the outside.
     
    gimpyshotrods likes this.
  14. David Gersic
    Joined: Feb 15, 2015
    Posts: 2,164

    David Gersic
    Member
    from DeKalb, IL

    Just thinking that if it’s flat it could have the clutch. If it’s round, it doesn’t.



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