[redhawk44]

Getting ready to install my 700R4 and I talk to my Bro-in-law , he says the only way to do it by the pressure method. Sometimes hes a pretty smart guy buy is still a Bro in law. So , I'm asking which is the best method for setting the 700R4, the TV cable method or the pressure method? Especially for the guys that have done both and who can direct me to the best tutorial for both methods?

[67Fbird]

tough call there. Most (as I ) would probably go TV cable. (I did on my 2004r install) While it is a very PICKY set up....it has been simplified ALOT by many makers with adapter arms and brackets. The pressure method I THINK you are referring to is a "constant pressure valve body assembly"? IIRC that requires a VERY good pump assembly as it is hard on the pump vanes.

NOTE: you still need the TV cable!!!...just for shift timing not pressure related

[Overkillphil]

Red, your B-I-L is probably talking about the common method of using a pressure gauge as there are various pressure ports on the outside of the case. Lookup online or get a book on what pressures you should see with the TV for each gear.

[67Fbird]

FYI the TV cable is the LIFE BLOOD of that tranny (unless you go with the constant pressure set-up) Just like the 2004r the geometry of the linkage can make or break it.

[Steve C.]

I can highly recommend the Bowtie Overdrives TV and Throttle Cable SYSTEMS.
That is we used on my 200 4R


http://www.bowtieoverdrives.com/

.

[redhawk44]

Thanks guys, I already have all the cable/linkages just looking for your past experiences . I will probably use the cable to get everything dialed in and then double check with a gauge to confirm that I've done it right.

[67Fbird]

the linkage geaometry is critically wierd....PITA... XXX* throttle angle should = YYY PSI.....

[Cliff R]

The geometry is easy. Just measure the distance ( find have someone measure one for you) from center on a later model Quadrajet on a 1980 something truck carb and make sure the carb you are using duplicates that number. You'll have to use a little common sense for the range of travel from where you have the TV cable attached. I'm sure that distance is available someplace on the Internet, and it avoids having to buy "special" expensive set-ups to accomplish a very simple task.

Combine your attachment point with an adjustable cable and position the bracket behind the carb apprx where the factory did. Move the throttle to the wide open position with the carb or TB, take out all the slack with the adjustable cable and start testing. Adjust if/as needed for the desired upshift and downshift points. They aren't really that fussy, but things done during the rebuild can effect line pressure so all are not the same.

If you are using the TCC it will need to be set-up to work much like the factory did. Here I like to route the voltage to the L/U solenoid thru a normally open vacuum switch hooked to ported vacuum then ground it on a normally open 4th gear pressure switch. Some will also route the supply voltage thru a brake-pedal switch as a fail safe.

This will only allow LU once the transmission reaches 4th gear (overdrive) and it will only apply at light engine load when ported vacuum is present. Any coasting, heavy or going to full throttle will instantly unlock the TCC. It will also lock and unlock driving in traffic in OD when you are on and off the throttle. Although a bit annoying it's important not to have the TCC locked up coasting as you can get some "shudder" from the drivetrain at lower vehicle speeds and it can be incredibly hard on the clutch.

I'd also add here that with the 700's and 4L60's you do not need a lot of rear gear. They have a 3.07 first gear ratio and fine with 2.73-3.08 gears. Starting out with 3.08's, for example is close to a TH350 or TH400 with 4.10's. You also get the added bonus of a 30 percent engine speed reduction in OD for low RPM high speed cruising.

If you want to map all this out use the following formula:

GEAR RATIO x MPH x 336 divided by TIRE DIAMETER. This will tell you the RPM's in 3rd gear or one to one.

For the RPM in OD take the result and multiply it by .70.

For example: 3.08 x 70mph x 336 divided by 26 equals 2786RPM's in high or 3rd gear. 2786 x .70 is 1950RPM's in 4th gear of OD.......hope this helps some......Cliff

[redhawk44]

Thats very valuable info Cliff! Thanks

I'd also add here that with the 700's and 4L60's you do not need a lot of rear gear. They have a 3.07 first gear ratio and fine with 2.73-3.08 gears. Starting out with 3.08's, for example is close to a TH350 or TH400 with 4.10's. You also get the added bonus of a 30 percent engine speed reduction in OD for low RPM high speed cruising.

If you want to map all this out use the following formula:

GEAR RATIO x MPH x 336 divided by TIRE DIAMETER. This will tell you the RPM's in 3rd gear or one to one.

For the RPM in OD take the result and multiply it by .70.

For example: 3.08 x 70mph x 336 divided by 26 equals 2786RPM's in high or 3rd gear. 2786 x .70 is 1950RPM's in 4th gear of OD.......hope this helps some......Cliff[/QUOTE]

[Cliff R]

Another "myth" with those units is that you will loose vehicle performance due to the big drop from the "low" 1st gear to 2nd gear. That nonsense. I've retrofitted 4L60's into a variety of vehicles including a 1967 Impala SS I used to own,

The Impala SS was a full restoration and powered by a "stout" 327 engine making around 1hp/CID. It had a 3.31 12 bolt and factory powergluide transmission. IT was a "turd" from a standing start and revved to high at 70mph for my liking. It also got poor fuel economy at 13-15mpg's.

I built a 1987 700-R4 for it and it completely changed everything about that vehicle. It was really quick off the line with the 3.07 first gear and dropped nicely to 2200rpm's at 70mph instead of just over 3000rpm's. Even with the big/heavy Impala powered by the little 327 the 1-2 upshift wasn't even noticed as it kept you planted in the seat the entire time. Fuel economy improved to around 18-20 and I nailed down 24-25mpg's a few times on long trips. The transmission change alone took a car that was a turd for performance and not much fun to drive into a really strong runner with excellent manners on the highway at higher vehicle speeds..........