700R4 TV cable adjustment ?

Discussion in 'Transmission & Driveline Topics' started by JMRSZ28, Nov 27, 2007.

  1. JMRSZ28

    JMRSZ28 New Member

    Nov 12, 2006
    Hello all. I want to get an expert opinion or two on setting up the TV cable on my new 700R4. I have read all the info from BTO and TCI. I have a TCI geometry corrector bracket and a universal cable. Here's my deal: If I use the TCI bracket and set it up as instructed I can get the TV plunger all the way in at WOT but it only goes about half way back out at idle (not enough return travel in carb linkage). If I don't use the bracket and hook it up straight to the lower linkage hole I actually get more travel and can adjust it so that the plunger is fully seated at WOT and about 75% out at idle.

    Everything I read says to make sure the geometry is correct (78* of travel, pin location 1.125" from CL, etc) and plunger must be fully depressed @ WOT, but not alot of info on the return position at idle.

    How critical is it that the TV plunger be all the way back out at idle?

    What would you do, use the TCI bracket with less travel or just use the lower hole in stock linkage? I really don't want to spend the $$ to get the tvmadez kit.
  2. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

    Moved for better trans eyes...
  3. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

    Feb 26, 2004
    Bloomington, MN
    Sorry.... I'm going to vote for TVmadeEZ.

    Improper TV cable adjustment can kill the transmission.
    If you are trying to find an adjustment that's the lesser of two evils, You're taking a gamble.

    I shelled out the $$$ for a TVmadeEZ setup when I installed my 200-4R.
    I didn't want to risk the investment by taking a shortcut with something critical to the life of the tranny.

    I'm just trying to be honest with the little bit of info I think I know about these OD trannys.
  4. jakeshoe

    jakeshoe Veteran Member Lifetime Gold Member

    Dec 8, 2000
    Republic of Texas
    The plunger doesn't come all the way out. It should be partially depressed with the cable at the idle position.

    I've used the TVMadEZ kit and it's "OK". It is great for a quick install, less fab work, and for the money because it includes the carb linkage, bracket, and cable, its not a bad deal.

    More often than not you don't need it, you oftentimes don't need the corrector brkt either.

    1.093-1.125 from CL to CL on the carb, approx 20* to the rear.
    TV cable bottomed out at WOT.

    That will keep the trans alive and more often then not you will have to back off the adjustment a click or two.

    It is better to be slightly too short on the CL to CL measurement than too long.
    Too short is less throw, so it keeps the TV plunger in the sleeve further in (higher pressure) at idle with the same WOT setting.

    Too long and you can get a situation where the plunger is too far out and you have no line rise on throttle tip in.

    I just did a 700-R4 a few weeks back in a '55 Chevy. $100K+ car and the high dollar trans was cooked because the high dollar RamJet 502 linkage wasn't properly setup. I caught it when I went to supervise the install.

    The problem was the TV CL to CL was too long at about 1.45 inches. This means at idle, the TV plunger was too far out and on initial throttle tip-in there was no line rise.

    On a stock 700 or 200 trans line pressure in Drive at idle should be 65-80 lbs. On a modded trans it can be as high as 90 psi, anything more than that and you will often have 2nd gear starts.

    This isn't much pressure and it should INSTANTLY come up anytime the throttle (cable) is moved. If you gently pull the cable and there is no movement on a pressure gauge, FIX it.

    90 psi of line isn't going to hold the clutches engaged behind a stout engine, even in a light car.
    On take-off the converter is multiplying torque about 2.0-2.5 times the crank torque.
    So lets say the flywheel torque at 1000 rpm on the 502 Ramjet is 275 lbs. The input shaft on the trans will see 550 lbs of torque leaving a stop light at minimum throttle.
    If the pressure doesn't spike, then the clutches slip.

    The problem with a too long CL to CL measurement is,
    at WOT all is OK.
    At every throttle angle less than WOT, the error becomes greater the closer to idle you get.

    So effectively, as long as you went WOT every time you moved the throttle, the trans would be OK, but it's actually the mild stop light to stop light driving that would kill it in that scenario.
  5. TheFly

    TheFly Guest

  6. blades67

    blades67 Veteran Member Lifetime Gold Member

    Oct 22, 2005
    Chandler, Arizona, USA
    Which ever way you go make sure you pick up a pressure guage so you can check for pressure rise when the TV cable is moved and to check the pressures for each gear. Just because the pressure is good at idle in park and/or neutral doesn't mean that all is good through the gears.

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