Possible Transmission Issue

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Ernest

G-Body Guru
Apr 28, 2016
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700R4

I took the carburetor off to give it a thorough external cleaning only, just carb sprayed every thing down along with the idle bleed passage ways. used an old toothbrush to gently scrub all the throttle bores, associated passage ways, throttle plates and shafts, dog leg boosters, etc, i also snugged all the throttle body/plate and accelerator pump screws and bowl bolts, the whole unit looking good as new.

I installed the carburetor back onto the intake, torqueing down the intake carb stud nuts, hooked up the fuel and vacuum lines, but left the throttle pedal and the TV cable unattached for the time being, the auto choke was set and started the engine, i planned on tuning the carb after it finally warmed up using a vacuum guage, within five minutes of warming up, i decided to check the trans fluid level, as i touched the LOKAR dipstick handle, it was hot like its been driven on the road on a summer day, not enough to burn, but hot hot, so i immediately turned the engine off, the fluid still looked normal and still smelled like new, i just changed the fluid/filter 3weeks ago, synthetic.

After hooking all the cables back up, i took it out for a test drive, even with a newly installed original GM/OEM throttle valve cable and sonnax cable corrector spring, i ditched the B&M adjustable tv cable that was installed prior, before, the 1-2 shifts always happened around 2000rpm or so, its been like that since i got the car 5months ago, the 1-2 shifts are now 2500rpm or so, an extra 500rpm bump, the 2-3 and 3-4 shifts, along with OD seem normal, thankfully.

Obviously it was my mistake not hooking everything back up befiore starting the engine, i did have a lQQk around online afterwards to get some info on if what i did could possibly hurt the transmission, all i could find is "NO, that it'll be ok to leave the tv cable unhooked just to tune the carb while idling", that made me a little feel better, but not entirely, from what i experienced with the trans fluid getting to such a high temp in a short amount of time, those kind of temps are never good on parts, regardless.

Perhaps, just from the thorough carb cleaning, the engine is seeing more fuel with no other changes and giving me that extra rpm, but that might just be wishful thinking or nieve on my part... so any of you more knowlegable transmission pros out there, what do you think, is it hurt even though it appears to be working ok for now?


Thanks
 
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69hurstolds

Geezer
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Jan 2, 2006
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Did you properly adjust the TV cable to the transmission? Or better yet, was your old one adjusted correctly? Is your TV cable bracket the stock one? You never said you adjusted it. It may be too tight giving you the later shift. Too loose would give you quick shifts. If too tight, while the engine is off, rotate the carburetor throttle lever under the hood manually all the way to full throttle. If you hear clicking when you do it, then it was too tight and now should be in the proper position if it is indeed the proper stock TV cable. It sounds like you are running a different carb than stock. Make sure you have the TV cable adapter bracket that goes with your carb to keep the TV cable in the proper "stock" location. A GM cable is not a cure all if you're not running a stock GM setup.

If too tight, that's a tad better than too loose. This axiom pertains to other stuff too. :) But a misadjusted TV cable is bad for you either way. A misadjusted cable can kill your transmission. This applies to the 200-4R as well.

This guy explains what is going on with a stocker (and with aftermarket carbs a bit) and how to adjust it. Good luck.


From Art Carr's website...

7. An incorrectly adjusted TV cable. (A) If the cable is adjusted too long, one of the following conditions may result: (1) early shifts, slipping, and/or no detent downshifts; (2) low line pressure. (B) If the cable is adjusted shore, or not hooked up at all, line pressure and shift points will rise and full throttle operation may not be possible.​


ADJUSTMENTS


Before adjusting the TV cable, check the following:
1. Transmission oil level. Correct if necessary.
2. Proper engine operation. This can cause problems similar to a malfunctioning transmission.
3. Dragging brakes. This can cause detract from vehicle performance and cause transmission malfunction.
4. Check the TV cable to insure that it is the right part for the vehicle.
5. Check the cable to insure that it is properly connected at the transmission.​

Adjustment procedure (self-adjusting cable)

1. Stop the engine.
2. Depress the adjusting tab and move the slider back through the fitting away from the carburetor until it stops.
3. Release the adjustment tab.
4. Move the throttle linkage to rest against the full throttle stop, then release it .
5. Check the cable to insure that it is not sticking or binding.
6. Road test the vehicle.
7. If the problem still exists, refer to the cable diagnosis section.​

tec1.jpg
 
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Ernest

G-Body Guru
Apr 28, 2016
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Texas
Thanks for the reply and details.

I have the correct geometry brackets(holley) and the new TV cable was already set correctly and road tested prior to this inccident.

I pressed in the "D" lock button, then pushed the slider into the housing/bracket towards the firewall, released the "D" lock button, i then manually opened the carb throttle linkage to WOT, the slider ratcheted out 1/4", the trans shifts like it should.

Before and after setup pics w/cable corrector spring...
 

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ELCAM

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Jun 19, 2021
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If it that hot at the top of the tube I would guess oil is getting up that high the empty tube would lose heat pretty fast, might be hot at the bottom but way cooler at the top. Run the car hot again and pull the dipstick and plug the dipstick tube with your finger to see if it is under pressure. Pressure like that might be from a plugged vent, overfilled system or maybe a leak in the cooling coil in the radiator.
 
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Ernest

G-Body Guru
Apr 28, 2016
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Its the heat transfer from the fluid, up the steel rod up to the handle, it was extremely hot.

But it didnt dawn on me till AFTER the fact, the 700R4 transmissions need a certain amount of pressure during idle when the inner cable is connected correctly to the carb throttle shaft, i had it completely disconnected, so the trans was receiveing less than optimal pressure, hence the over heating of sorts, then the change of the 1-2 shift was concerning that i might have accidently damaged something internally for the extra rpm upshift now.
 

83MonteCarloSS

Greasemonkey
Oct 5, 2015
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When you have the TV cable off the trans applies elevated pressure as a protection, ie. cable breakage. I'm assuming being at max pressure long enough caused the heat. Since it wasn't shifting it should be fine.

Now with the cable adjusted properly, is the temperature normal after driving?
 
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64nailhead

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The factory setting procedure that 69hurstolds referenced is what a factory tech performed on completely stock setups. That is an excellent starting point, but that’s it if your setup isn’t stock.

TV cable adjustment should be dialed in with a line pressure gauge. It’s not hard at all and can be done in less than hour if you can drive, hold the gauge and read it at the same time.
 

Ernest

G-Body Guru
Apr 28, 2016
720
963
93
Texas
The temps have been been normal before and after this inncident.... it appears to be a built trans from somewhere because of the even coat of black paint of the case thats typical from the aftermarket sector, but i have no proof of that nor history on the trans, so i assume nothing... the trans was NEVER shifted into any gear while idling when the tv cable was disconnected from the carb, kept it in park the entire time... and i havent used a pressure guage of any sort since i've owned the car.
 

69hurstolds

Geezer
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Jan 2, 2006
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The factory setting procedure that 69hurstolds referenced is what a factory tech performed on completely stock setups. That is an excellent starting point, but that’s it if your setup isn’t stock.

TV cable adjustment should be dialed in with a line pressure gauge. It’s not hard at all and can be done in less than hour if you can drive, hold the gauge and read it at the same time.
And how do you use a pressure gage to set them? 🤷‍♂️ This is an honest question. I've always run the stock setup on the 307s, and with the modified cars have always been big blocks with the TH400 so no need for cable adjustments there. Not sure if you can adjust a stock cable with a gage and make it stay there unless you're able to change lengths since they auto adjust. You can use a gage to see what's going on, but unless you know where pressures are SUPPOSED to be at certain throttle openings, a gage won't help you adjust any settings, per se. I guess you could get some of those cheater springs to put on the front of the cable to raise pressures a bit, but those, to me, are simply band-aids and not really fixing whatever it is that you want to fix.

If you have the correction lever for the aftermarket carb, the stock placed manifold bracket, and the cable remains level, you should be within specs using the stock setup procedure. The simple fact of making sure the cable has no slack (slight preload at idle, meaning it's already touching the TV plunger), remains level throughout the travel, and hitting the full stop on the TV valve when you're full carb throttle travel is the key. Granted, stock is where I live mostly, but when changing fluid, I always physically check the linkage on the valve and have a helper go full throttle to check that it's doing what it's supposed to do and when it's supposed to do it. Playing with the TV cable, IMO, is NOT the best way to adjust your shift points/feel, etc. You can play with the governor setpoints to really dial in where your shift points need to be. But I'm far from an expert on playing mix n match with governors. I do know that when the governor pressure overcomes TV pressure, you're getting to the next shift. So once you get the TV cable adjusted properly, there's really nothing left to do except hook up the gage and make sure that when you start to open the throttle, you get a pressure rise instantly from your transmission. And if you're already preloaded, it should already be doing that.
 
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83MonteCarloSS

Greasemonkey
Oct 5, 2015
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One thing to watch out for with the carb corrector bracket is the exact geometry. I don't like the fact that they have you wallow out (elongate) one of the holes in the bracket.

I had my TV cable set up for full pull at WOT and checked everything from idle to WOT with a gauge and was happy with it. Drove it for awhile and wanted a little firmer shifts and the shifts to occur at a little higher rpm.

Long story short, I found by comparing my Edelbrock with corrector setup to a stock carb that the throw was shorter on the stock. I had to elongate the hole in the corrector bracket more to move the bracket location on the carb to get the correct amount of linear travel for the TV cable. That bumped up my shift points and feel.
 
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