I'm trying to understand exactly how the adjustment works for a TV cable for a 200-4R/700R4 when you install it for the first time or try to adjust it. I've read several instruction sheets and watched several installation videos on youtube and I don't feel like ANY of them do a good job of explaining what is occurring when you push the D shaped adjustment button and slide the plastic piece toward the front of the car to soften the shifts or slide it rearward to firm them up. I don't have a spare TV cable I cay play around with to increase my understanding and I'm not about to go mucking around with the one on my car since I didn't install it and I don't want to screw anything up. Here is what I think I understand, please correct me if I'm wrong: 1. The TV cable has a single length of steel braided wire in it. 2. The end of the braided wire that connects to the transmission has a little loop on it that hooks onto a rod. Pulling the cable pulls on the rod. The other end of this rod connects to one end of a bracket that seesaws on a pivot. The other end of the bracket pushes on a plunger inside the valve body. So, pulling the TV cable ultimately pushes on the plunger. 3. The other end of the steel braided wire, at the carburetor end, has a plastic connector that hooks onto a stud on the carb lever. 4. Around the outside of the braided wire, shorter than the braided cable, is a semi rigid sheath or tube. One end of the sheath bolts to the transmission case, the other end has a square plastic provision that snaps into a bracket attached to the carburetor. The back of that square provision has the adjustment button. Some aftermarket TV cables have an adjustable length sheath. 5. The steel braided cable can slide freely everywhere in the sheath. 6. At the front of the sheath at the carburetor end is a plastic tube that can slide forward or rearward when you push the adjustment button in. 7. Sliding this tube forward softens the shifts and can be dangerous to the transmission if it is set too soft. 8. Sliding this tube rearward firms the shifts and will not harm the transmission if it is set too tight. 9. Pushing the adjustment button in, then pushing the tube toward the rear of the car, then opening the throttle will "ratchet" the tube toward the front of the car, and this is one way to make the initial adjustment. Here is what I don't understand: 1. Are the tube and the sheath one piece? 2. How does moving the tube forward or rearward increase or decrease the tension on the cable if the cable can slide freely in the tube and sheath? This video confused me at about 45 seconds in. He adjusted the tube forward, and that somehow created slack in the cable. I don't understand this at all! ""
I appreciate the fact that you are being careful with this adjustment, I've heard stories about transmissions got burned-up in less then a mile due to incorrect TV cable adjustments. TV stands for throttle valve which is a plunger in the valve body. Since the 200R4 and 700R4 have no vacuum modulator, this is the only information your transmission has. First, the geometry must be correct at the carb (or throttle body), the stud the cable snaps on to should be the same distance in behind of the throttle plate shaft at idle as it is in front at full throttle. The adjustment is simple, press the "D" latch, pull the housing back, move the throttle to full throttle position and release it. This should move the housing adjuster forward and make a snapping sound. Doing this synchronizes full throttle of the throttle plate with full throttle of the throttle valve in the valve body. That's all there is to it.
Can you post a photo of the carb linkage, cable, and bracketry you have? There are a few different styles, and not all of have the "D" detent for "auto" adjusting...
Yes the first thing you need to determine is if you have the correct geometry and linkage at the carb. Second this isn’t an adjustment per say it’s setup to be set and left alone. tv made ez explains the symptoms of either too tight or too loose. But if your geometry isn’t right you are not going to fix it until that’s fixed. 1. which carb? 2. Which tv cable bracket? 3. always start with a new TV cable and housing 4. When in doubt use a line pressure gauge to verify it falls in spec. 5. Dont drive it unless it’s correct it will burn the trans up quick. They must have changed their website I can’t find their “TV101 info” but I have it saved in a word doc I can try to find it. good info https://www.bowtieoverdrives.com/catalog/catalog.php?Action=GETSUBCAT&CATID=WA3
Normally what you do is press the D button and hold it while you pull the carb linkage to pull 100% open. That sets the TV cable.
It looks like he is just giving a demo of what goes on inside the tranny when the cable is correct, loose, or tight. I would not use this video to set the cable. Where do you find the correct geometry for a Q-jet? Or, where, I assume its the same for any carb.
It looks like Bowtie Overdrive's EZ page went away when the "internet" stopped using Adobe Flash for animations (the pages were full of animations). I used their system chasing a problem with my 700R4 and while it didn't solve my particular issue, it was indeed easy and eliminated the possibility of having it wrong at the carb. Check this page for their Quadra-Jet kits. You might not need the cable, but the bracketry and carb adapter will ensure the correct carburetor geometry. http://www.bowtieoverdrives.com/catalog/catalog.php?Action=GETSUBCAT&CATID=WA3A4
no its different geometry for each carb. I will have to dig up my word docs that explain this. 1. what carb are you using? 2. What linkage are you using?
My carb is a FiTech throttle body. I set up neither the fuel injection nor the linkage in this car, but here is a photo of it for reference. Thanks for the replies so far, but I'm not looking to make any adjustment myself. Right now I think it works fine. I'll be bringing the car to my transmission guy later this summer for a couple other things and so I will have him make any adjustments if it needs it. My question was an attempt to improve my own understanding of how the TV cable itself works. I don't understand how the components of the cable work with each other to get the desired result against the valve body plunger by moving that plastic slider back and forth. Moving that slider forward or rearward decreases or increases the tension on the steel braided inner cable, and I don't understand how it does that.
The slider is part of the cable housing. You are essentially lengthening or shortening the housing by adjusting the slider. This adds or removes slack from the cable between the transmission and the forward cable mounting point. Set correctly, the throttle valve will be fully depressed when the carb linkage is at wot. If for example the slider is too far forward, then the cable housing will be too short and there will be too much slack in the cable and the Throttle valve will not be fully depressed at wot. Also the pressure rise will lag behind your throttle position at all times, possibly allowing slippage.
I believe the D adjustment is for fine adjustment of the cable due to cable stretch, etc. The ratio or swing of movement has to be correct also.
What exactly is it that gets shorter when you move that slider towards the front of the car? The housing or sheath is attached to the transmission case at one and the carb bracket at the other. If anything, moving that tube forward makes the housing effectively LONGER, at least in my head.
The sheathed length of cable between the carb side cable mount and the transmission cable mount is what gets shorter. As that tube moves forward, it is pulling the sheath with it through the forward mounting point.
The cable tube bottoms at the transmission end, but the adjustment happens at the carb end. The length of the tube is what determines the lever to plunger relationship in the transmission pan. That is the critical part, making sure you get WOT (both for the carb/throttle body while the throttle valve plunger bottoms inside of the valve body.
OK, so that makes sense. But still, the steel braided cable has a fixed length between the transmission link rod and the pivoting carb linkage. How does changing the sheath length between the trans and carb bracket change the cable tension? I don't know if this comparison makes any sense but I'm imagining it's similar to wearing a long sleeve sweatshirt with an elastic cuff. Rolling your sleeve up to near your elbow (lengthening the sheath between the carb bracket and trans) causes the sleeve to bunch up and create friction around your arm (steel braided cable).
The actual cable is fixed at both ends, yes. But there can be loose play between the throttle valve plunger and the bracket that actuates it. Making the sheath longer between the mounting points pulls on the cable ends to take up this slack, because the cable itself is fixed length. It's not really cable tension I think, but just eliminating freeplay in the connecting pieces.
The cable really only experiences the spring tension of the throttle valve return spring, once all freeplay has been removed, assuming the cable has been adjusted correctly.
Alright well I think I'm getting it. I'm sure it'll all become crystal clear randomly at 3am when I'm half awake
