Technical 700R4 TV cable adjustment...JUST CAN'T GET IT RIGHT!!

Hey guys. In my 1961 Chevy K20 truck, I have a newly rebuilt 700R4 behind a 454. I can't seem to get this damn TV cable set up correctly.

Right now, heres the situation:
1-2: 10-12 MPH
2-3: 30 MPH
3-4: 40-45

Right after I shift into second, if I hammer it, I do have kickdown back into first.

Does that sound correct? My truck is geared really high...We're talking close to 3.08s...

 

What's the problem?

 

I spent 1200 bucks having the thing rebuilt and I just want to make sure that these are the norm and that my TV Cable is set correctly. I can't afford another rebuild. I calculated it, and I have 3.55s and 33s

 

I don't see any problem you can't live with.
3.08's or 3.55's ? Big difference .
If the governor is not set up for something close to your gear ratio, you may have to dick around with it, for it to feel right.
Sounds like you've got enough pressure working, where you won't hurt anything.
You could always put a pressure gauge on it and check it.

 

It must have 3.55s because at 1600 RPM in .70 overdrive, I am at 60 MPH or so (my speedo is wrong, but its anywhere from 60-63)

I have a Corvette Servo, Alto Red clutches and all of that good stuff. Also have an aux tranny cooler.
I just keep dicking around with my TV cable length because I'm terrified of burning up my transmission. I wish I had the rebuilder put in a CPVB.

 

You won't burn it up with the pressures just a bit out of spec. for the original application.

 

OK! Thank you very much for your help. I figured I would just verify my shift points and all of that stuff. I've adjusted the damn thing maybe 15 times. I think I finally got it to a good place but I was worried the 1st-2nd shift was too early which would mean the line pressure was too low? Maybe not, haha!

 

What carburetor? Most aftermarket ones need a cable geometry correction arm.

 

Its a 1407 Edelbrock. I do have the special TV cable bracket for it

 

Well, I might be wrong. The TV cable is mounted in the right place,but I don't see a special TV cable linkage correction plate. The rebuilder didn't say anything was wrong with it so maybe it had one? I'm not sure. I'll go out and have a look at it tomorrow.

 

Without one, it has the correct geometry for a TH350. It's not the same as a 700R4.

 

Hmmm...I don't think the mechanic ever put that part on. Well, bend me over and call me daddy...

 

So, how screwed am I that there is no geometry correction bracket. Let's say I go buy one first thing tomorrow, how much did I just shorten the life of my transmission? Also, it is possible that there is a bracket on there, I just don't remember ever seeing something shiny (it was new)

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Go to the BowtieOverdrives.com and learn how important that this is!

 

I know how important the TV cable is! I'm more worried about how bad not having the bracket is if your shift points seem alright and I'm not getting any slippage

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....T.V. Cable Adjustment
WARNING: PERMANENT DAMAGE WILL OCCUR IF THE T.V. CABLE IS NOT ADJUSTED OR HOOKED UP. THE DAMAGE WILL OCCUR WITHIN A FEW FEET OF DRIVING THE VEHICLE!......

A 700-4R’s shifting can be erratic as a result of improper TV cable lever geometry. In many cases, the shifts are poorly timed and may be early and soft, late and harsh, or a combination of both.

Bowtie overdrives article

 

as far as I know when your carb is at w.o.t there should be no slack in the tv cable.some thing im anxious to get 100%correct not too difficult to do

 

Firstly, you may or may not need a bracket, but if you do are checking measurements from this diagram, then there is always the possibility of making one to fit your actually project needs.
It ain't that hard.
Once that is worked out then you need to set the cable travel up.
Also not that hard if you got the first step done right.
Ensure you have accurate angle and radius measurements built in...
I say one step at a time and always make sure you have the correct amount of oil, as too little can make it do funny stuff as I learned.

 

This. Actually a very small measure of more extension, like a 16th or less at WFO.

 

For shits and giggles, I ordered the bracket. It's a 1407 carb but with the stock TV cable housing, the geometry can't be right. For peace of mind, $30 is worth it.

Main reason I did it is I thought I felt the tranny slip in first gear today and that scared the shit out of me. It'll be here tomorrow

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People, you've got to remember that Bowtie sells complete transmissions, and this is their legalese disclaimer.
Notice it says NOT ADJUSTED, not "not adjusted properly" .
You're not going to burn one up if the shift points are off a little bit.
Again, put a pressure gauge on it.

 

The bracket definitely won't hurt having it on. I had the same problem with the shift points and the cure was to get an adjustable governor spring and weight kit. Kind of a PITA to get the right combo, because it's all hit or miss the first couple of tries, but raised my shift points on 1-2, and 2-3 up where they should be. I used a TCI kit and it ran about $60.00, took 4 tries to get it where I wanted it.

 

DO NOT use the TV cable to set shift points. That isn't its purpose. The proper setting for that is checked with a pressure gauge on a test port. There should be a well defined pressure in idle, shifted into first, & with partial throttle in first. I set mine with input from BowTie Overdrives where I bought my carb TV lever. They walked me through the testing over the phone and gave me the pressure settings as a service for buying their widget. I'm sure the pressure settings are available on line or in Chilton's manual.

The proper way to set shift points is by adjusting governor weight. Luckily governors are dirt cheap. I got several for my 200R4 for less than $12 each to play with. I put a 200R4 (very similar to the 700) behind a mildly hopped up 307 w/ 3.55 rear gears and the governor in my rebuilt junkyard tranny out of a grocery getter was shifting too early. Here is a photo story of necessary modification.

http://www.hotrodders.com/forum/journal.php?action=view&journalid=2439

 

True enough, but the 700 governor is in the case , similar to a 350, whereas the 200 4 r is a completely different style and is inside the pan, making it much harder to deal with.

 

Don't have a pressure gauge unfortunately, might be worth it to buy one, but I'm not to picky about my shift points as long as it doesn't hold the gear too long and doesn't burn up my clutches, I'm good.. When it shifts out of first at 20, it's holding the gear way too long for the truck. When it shifts into second at 5MPH ( mine doesn't do this, it's way too low)

Yup, it was a little bit of money to guarantee peace of mind. Worth it for me. I can't afford another tranny rebuild.

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Try this document and see if you can find what you need in it.
I believe it covers most everything.

 

Yes I didn't mention that. My 200R4 requires removing the pan every time I want to try another governor. The 7004R has the external access plate making the testing much easier. That being said, it is a pretty easy task otherwise to adjust shift points with modified governor weights. Screw one up, just toss it and get a new one. Pretty cheap.

 

The TV cable does not control the shift points. It controls THE LINE PRESSURE IN THE TRANSMISSION.

Slack that cable, and the friction material starts slipping, wearing, and overheating.

You absolutely will do damage to the transmission if it is not adjusted properly. I have personally rebuilt over 20 700R4's that were damaged because the owner either did not hook up the cable, hooked it up without a geometry corrector, and/or adjusted the cable wrong. Either they had no idea, were convinced that it was just a kickdown cable, or were told that exact adjustment was not critical.

Don't listen to advice that this is not the case. You will lose hundreds, if not thousands of dollars making this mistake.

Those who have "gotten away with it" are lucky. Luck is neither a financial plan, nor a survival strategy.

 

release the lock on the cable, open the carb all the way and lock the cable....done

 

You are correct about the shift points control.
Earlier, I should have said you can't set up and adjust a TV cable going by the shift points.