I don't think it's shifting into 3rd

[pkjorlie]

Just got my Bronco II out of storage. I'm lov'n it!

Only problem I have is I don't think it is shifting into 3rd gear. I can only feel the C4 shift once. I don't have a taco-meter to check the rpm's at 55. Are there different types of vacuum modulators?

[plowboy34]

yes there are different modulators. It should have a colored stripe around it. I don't remember exactly what color means what. As far as knowing if it is in 3rd be cruising at about 45mph then manually pull it down to second and you should feel it downshift. You have to be just cruising though not stomping on it. If it does downshift maybe your starting out in second, if you manually pull it down to first it should not downshift until you are at 25mph or less. Also you can manually start out in first run it up to decent rpm then manually shift to second then the same for drive. Even if the modulator is bad manually shifting usually makes the tranny shift as long as you run the rpm up decently high. Sometimes you do have to feather the throttle a little to get it to go to drive. Also even if modulator is bad if you run the rpm where you know it's 5k or better it should shift. The modulator is to make it shift at light throttle but tranny is designed to shift at high speeds.

[pkjorlie]

Plowboy, you are probably right. It may be that it is shifting into 3rd and it is starting out in 2nd. It really doesn't wind out at 55. What really alerted to me was that I'm getting less than 8mpg. That's why I thought it wasn't going into 3rd. I can live with it starting in 2nd gear for now.
Now I come to find that the choke wasn't opening fully. The cable is very long and instead of cutting it shorter I just coiled it behind the carb. If I pull the choke, and push it back in, it doesn't open all the way. Sometimes I overlook the simple ....

[Dave]

Darn, reminds me that someone promised to find a tach for you. Well I did go thru one big cabinet but didn't fight my way to the other end. Still think I have one, owe you one! Already to head for the basement? Got some nasty stuff heading this way, at least, you look better down there right now. Did get the Stang out Sat and sure is fun again!
Dave/Mac to you

[pkjorlie]

You know, I distinctly remember doing the 2000-2500 rpm-hour run-in of the motor after I rebuilt it. But I have no recall of how I determined the speed of the motor when I did it.

[Dave]

Happen to have or use a dwell meter with the tach built in?
By the way, you didn't do such a hot job on that Grande Coulee unit, having to upgrade it already! Only been 35 years?
Dave of the Nord

[pkjorlie]

Don't think I have one but I'll check.

Grand Coulee service units were done in 1982 so about 29 years ago. What happened to them? They were Basic Mechanical Cabinet Actuators. Upgrade to Digital?

[pkjorlie]

Well now I learned something and I'm gonna have to go to bed.

I learned to ajust my vacuum modulator on my C4 Transmission.

http://www.ehow.com/how_6952775_adjust- ... lator.html

It is shifting into 3rd. I had to turn the ajustment screw 4 full turns to actually feel the transmission shift from 1st to 2nd. The Bronco II is such a small vehicle for a 302 V8 that it was shifting into 2nd before I even got out of the driveway. Still I have to punch the accelerator on startup to keep it in 1st gear for the first 50-100 feet. But there now is a noticeable shift.

Now if I could just get the gas mileage above 10mpg.

[Dave]

Hey there you down there!
Actually that 302/C-4 combo was used on the lighter Mustangs types, really designed for them. Sure hope you find the snake that keeps bitting on that mileage. Not fun to drive with that gas mileage and the way prices are now. With your gearing and tires sizes, I'm with you and think of the jetting or something. I was always able to run mine basically stock out of the box. I know, no help here!
Take care, got to drop down when ever it gets nice (August). Think it's snowing up in Phillips.
Dave