Car surges when put in gear

69mopar man

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69 fury with 318 auto, car surges and clunks when put in gear? Runs good with rebuilt carb, has good red tranny fluid , and ideas
 
Clunks are usually from too high of a hot base idle speed, plus can be worn u-joints. Maybe from worn splines on the trans output shaft yoke? Is the clunk from the rear of the vehicle or more toward the front?

Surge would be due to an incorrect air/fuel ratio and/or a vacuum leak. Is the hot base idle mixture and speed adjusted to FSM specs?
 
If surges means: lurches forward, I agree with too high an idle speed.

What carb adjustments did you make when you installed the rebuilt carburetor?
 
Torqueflites are tough but one surefire way to break a low/reverse band is to jump into reverse at too high idle. Don't do it. Select D to slow the motor down, then go to R.

Idle in neutral should be 600-700 rpm, 500 in gear?

Clunk is prob any of the above, especially the rear U joint, which is disastrous enough but can't polevault your car like the front one failing...

Round here, if I lose a U joint, it would be dropping down into the canyon, then I'd have a runaway load, jump out - if door opens - or kiss it goodbye in truck, either way the stuff of nightmares, those U joints are my life.

I worked at a driveline shop right out of school, this is in '91. We built them from scratch, but I sure got good at doing U joints, still have the Proto cross peen BFH in my toolbox but at 4lbs I rarely ever use it, or have to do a U joint. Once I get one squared away, Spicer with zerk in cap, I never have to do one again.
 
I will play around with carb adjustments maybe it’s not set right , I have no way to know idle speed
 
Idle speed can be set by ear, easy, but I really recommend installing a tach in your car. I won't drive any personal vehicle without one. Fairly easy to wire up, power, ground, light, and to the negative side of the coil through the firewall, a couple hours if you obsessively solder and heat shrink all terminal ends and connections, which is best but optional.

At any rate, when the idle is correct, assuming your engine is in good mechanical condition with timing and carburation set correctly, the engine should sound like an idling engine, not racing. Not too high, not too low, and it should not lurch into gear hard - a great way to break reverse band in a transmission - and it should not try to take off on its own, it should idle in gear without any noticeable pull.
 
You can also buy a multimeter with a tach built in. Fluke makes excellent quality, but they're not cheap.
 
Friends don't let friends use digital tachs ;]

My preferred weapon of choice for vintage tachometers on a budget, the old Sun tachs that used to be everywhere. They usually work quite well, forever apparently, fairy simple to mount on old Mopar steering columns to be seen well.

P1030581.JPG
 
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