350 not shifting

Ok, since I'm at my wit's end, I thought I'd ask for some advice. I have a 350 tranny behind a small block in my '53 Chevy wagon. I just got the car on the road and it's not shifting like it should. I can get it to shift out of first, but I have to rev it in order to get it to work. Everything I've read says it's the vacuum signal that shifts the transmission. So far I've replaced the vacuum modulator, replaced the vacuum line (hardline with VERY short pieces of rubber hose on each end), and backed the adustment on the modulator all the way out. It's better than it was at first, but still doesn't shift anywhere near when it should. The transmission is a fresh rebuild. What am I missing?

 

Pull the governor cover (rear left, held on with clip), pull the governor, and replace the gear that is attached to it.

Cosmo

 

I think the modulator valve screw should be run in some (to firm up the shift) but I may be wrong. Is the fluid level normal?

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Make sure the vacuum source is correct. FULL vacuum at idle. If you have it on "ported" vacuum (low or no vacuum at idle for vacuum advance) it won't shift right

 

It's got full vacuum, drivers side port on Edelbrock carb.

 

Not questioning your ability but are you sure you have enough fluid in the transmission? HRP

 

Has a shift kit been installed? If not its probably the governor. There is a valve inside the governor that could be sticking also.

 

X2 on checking the governor gear

 

I was thinking the same thing. The trans takes at least 12 quarts. A bit more if you have an additional trans cooler.

 

Tranny's full; no shift kit.

 

And remember to check it hot, while running.

 

If its stuck in passing gear it wouldn't shift. check lever on trans.

 

2nd gear accumulator piston or band. How is reverse? If it slips then the pump pressure may be low.

 

Do you have a full range of gears,does the car move in 1,2 and drive? HRP

 

Could be something as small as a pinhole in the vacuum tube to the modulator. My buddy's van had the same problem, turned out to be a dry-rotted cracked hose.

 

Had the same issue today in mine. Turned out to be low fluid level. Check it over and over, sometimes the fluid level doesn't read properly on the stick.

 

Or check kickdown cable @ the carb in case it's hung up

 

There are 3 things that can cause a no upshift:
no governor pressure, stuck valve or stripped gear
low vacuum, make sure you have 15" of vacuum AT the modulator at idle
stuck kickdown cable

 

x2 on the kickdown cable. Did not see it mentioned. How do you have it adjusted?

 

Kickdown cable is fine, it is tight at WOT and loose at idle. I have a Lokar flexible dipstick, maybe it's not reading right. How much fluid should a 350 hold? 9-10 Qts. including converter?

 

How deep into the transmission does the dipstick tube go? I've found a couple that someone forgot to install the tube with the transmission and cut some of it off to get it in after installation. Without the tube inside the transmission, fluid can be sprayed onto the stick making the level look higher than it actually is. With the stick removed and wiped clean, have a helper run the engine in neutral and shut it off. As soon as the engine stops, put the dip stick in and check the level.

 

12 Quarts with the torque converter,,as for the Lokar flexible stick..do what I did with mine,,throw it away! HRP

 

THIS! They're pure garbage

 

You said its a fresh rebuild,why not take it to whoever rebuilt it and let them check it.

 

Any updates? HRP

 

Pull your vacuum line off the carb, and put it onto a dedicated port/tee on the intake manifold itself.

 

That's what I was thinking.Didnt think there was enough vacuum off the carb to make it work right.

 

Try removing the kick down you really don't need it make sure it has spring tension.

 

If your modulator is adjustable, back the screw " out " to make an earlier shift, " in ", to make a later shift.

 

I added fluid and adjusted the modulator (I had it backed all the way out and it still wouldn't shift). I pulled the governor and it seems fine, but I do have another one.

The governor:


I don't know if it's worth pulling it apart again if this one looks fine. I have the vacuum hooked to the driver's side port on the edelbrock carb. It's supposed to be full manifold vacuum.

It's a fresh rebuild, but I've been building the car for eight years and the guy who rebuilt it is now dead; I can't really take it to him.

I can get it to shift, but it's still shifting really late. I tried disconnecting the kickdown cable, still not a difference. What should be my next course of action?