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Your modulator is hooked to ported vacuum, remove the hose from the side of the carb and hook it to manifold vacuum. Your distributor should be hooked the port on the side of the carb. Install a tee fitting where the brake booster is hooked to intake, hook modulator hose to that Tee. Just cap port on carb, try moving distributor hose over later if transmission works ok.
Your modulator is hooked to ported vacuum, remove the hose from the side of the carb and hook it to manifold vacuum. Your distributor should be hooked the port on the side of the carb. Install a tee fitting where the brake booster is hooked to intake, hook modulator hose to that Tee. Just cap port on carb, try moving distributor hose over later if transmission works ok.
Is everybody in agreement that the modulator is being vacuumed wrong? If so can you tell me where it should go. Can you look at picture for reference on how it's hooked up now? Thank you. Current connections..
Yet another problem with Big Mamu..
Had transmission rebuilt. Truck won't shift past 3rd gear. Was told I need the throttle valve linkage. Cant find it anywhere. Can you guys help me?
It onl;y has three forward gears.
Originally Posted by grzzly71
When im driving the truck, i can manually shift from 1 to 2 the D but I dont get nothing after that. The engine revs high and transmission wont give me another gear. If it in D itll only shift if i release the throttle up until what i am calling 3rd gear. Nothing after that. Engine is REving real high. Im afraid im gonna blow my engine..
After 1st & 2nd & 3rd, there is only Neutral, then Reverse and finally .... Park.
You are missing what is commonly referred to as a “vacuum tree“ at the back of your manifold.
Where the single large hose for the brake booster is fitted to a single barbed fitting (presumably) most passenger cars and trucks of the era would’ve had a multi port vacuum manifold many of which did look like a tree with multiple barbed hose fittings of various sizes protruding from it.
Some were in fact as simple as manifolds, being just a square brass block with a couple of fittings soldered to it, but most were tree like.
See if you can find a multi port version and replace the single barbed fitting with one that will accommodate all of your needs. A model with at least one 3/8 inch fitting and a couple of the smaller ones.
That would be the typical location for connecting the transmission vacuum modulator and the vacuum brake booster.
The one to the upper part of the carburetor air cleaner flange that runs down to the exhaust manifold is correct. That is your choke stove intake that allows clean air to run through it down to the exhaust manifold to be preheated before running back up to the automatic choke on the carburetor.
if you haven’t already, make sure your PCV valve runs from one valve cover to a 3/8 inch hose fitting that is in the common plenum area at the base of the carburetor or top of the intake manifold beneath the carburetor.
Or on many Fords it was located in a spacer plate under the carburetor.
Bingo.
that would work, but count how many vacuum lines you have that need full vacuum and maybe find one that has more than just two ports if needed.
Otherwise if it’s just the brake booster and the transmission modulator, that one would be perfect.
It will drive fine with the kickdown tied off. The governor will kick it back to 2 and 1 when speed decreases. Lot of guys drive them without kickdown attached. I'm kind of wondering if you are in 4 Lo since you say its revving so high and won't go over 35. Another thing to note, if you've never run old trucks, lots of these had 4.10 gears and will rev much higher than modern vehicles with OD transmissions and lock up converters. You can run it at 2500-3000 RPM all day. That's how it was designed.
Nate..looks like you were right as well. Truck was in 4L. I messed with the 4wd shifter and walla...it's rolling down the highway at 55-60 mph..Thank you all for the advice.
I have 1 more question regarding this issue (hopefully). Currently carb is hooked up as shown in following pictures. Seems to me throttle spring might be wrong because it's hooked up to where the kick down rod(which I found one at local junk yard) is supposed to hook up. I believe this is where kick down rod goes.. Should that spring be there? Can the spring and kickdown rod be in the same spot? What are these holes for? Should spring be pulling the other way?
I know, not the same carb ... but if you use a throttle return spring below thw throttle shaft in thos lower holes, you need to anchor it to a bracket that once was at the rear. Notice the blue spring.
I had to fashion an extension for my kickdown because the 4 barrel carb moves the throttle shaft forward on the intake.
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