69 RR running rough/jerking in low gear/at low speeds

[Etcher6]

Hi fellow MOPAR enthusiasts. I have a '69 Roadrunner with a 500 wedge crate motor and a newly installed TREMEC TKO 5 speed. It was a conversion from an automatic to manual transmission. I should also mention that a Firebox 6 Ignition Controller was also installed (similar to an MSD 6AL) . The problem I'm having is that when driving in slow moving traffic or even in residential areas, the car continues to "jerk", making it a very miserable ride. I've tried switching gears to accommodate the lower speeds but it doesn't seem to help. This will truly make riding in any car cruise miserable at the slow speeds. Any ideas if this is a correctable problem or will I just have to live with it? Timing? The ignition controller?

Thanks in advance for any thoughts/recommendations.

 

[Dennis H]

RPM's? Mine can lope around at about 1000 in 5th in town with light throttle apps. My pals 700 HP 'Cuda will buck until it gets to about 1850.

 

[nm9stheham]

This is not uncommon even with stock motors and manual trannies; my '62 Dart with stock 225 /6, 3 speed manual, and my '09 Challenger R/T 6 speed both do that a bit; with your big engine, I expect it to be worse. I just push in the clutch and coast a bit, then release and apply a little gas, and then repeat; good for building up your left leg muscles!

 

[coloradodave]

Sometimes running a bit lean on the idle / low speed circuits will cause this. Put a vacuum gauge on the motor and see if richening up the idle mixture screws to the highest vacuum reading helps.

 

[Etcher6]

Thanks for the reply. At about 2100+ it becomes a tad more "user friendly".

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Thanks. Working the clutch a bit more down our street seems to work a bit better. I just need to find a way to work the right leg as well. :icon_smile: The hydraulic clutch takes a bit to get used to...... no play, very stiff, and very little travel required to engage.

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Thanks for the advice. I'll have that checked out this week.

 

[nm9stheham]

If you really want some jerking, try it on an old, empty 2-ton logging truck with the rear axle in low range! Oh yeah, my old Jeep CJ7 (151 ci inline 4) would do that too...

 

[coloradodave]

Thanks for the reply. At about 2100+ it becomes a tad more "user friendly".

- - - Updated - - -

Thanks. Working the clutch a bit more down our street seems to work a bit better. I just need to find a way to work the right leg as well. :icon_smile: The hydraulic clutch takes a bit to get used to...... no play, very stiff, and very little travel required to engage.

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Thanks for the advice. I'll have that checked out this week.

If your hydraulic clutch is 'very' stiff, something is wrong. It shouldn't be if the ratios on the pedal linkage are correct. Don't get used to it; it's not right...