Noise at shift, during hard accel.

[ckt]

During hard acceleration (not full trottle)my truck makes a noise at the time of shifting (usually shift into 4 or 5 gear). At the same time as the noise, the truck sort of jerks. Has anyone seen this problem? The dealer has no clue.

[Rhoward225]

I've been hearing something like this lately.
It's kinda like a rat-a-tap-tap-? to me.
It only does it when I have the programmer on.
But I know my torqe converter is on it's last leg. I have 200,000 on mine, 50% pulling 8,000 to 16,000 lbs. How many miles do you have on your's? I think the noise is comeing from the converter. I have had my converter dis-engage at 65 mph. under a load here lately!!!

[ckt]

My truck has only 13000 miles. I have had my torque converter detach only at lower speed (around 20 mph)on a down hill. When this happens, I try to accelerate and I am not connected to anything, just let off the gas, then back on the trottle and everything works. The dealership said this is common. I'm not so sure.

When you hear the noise, does your truck jerk?, and is it only on hard acceleration, similar to mine? Also curious, have you used the programmer most of the time you have had the truck? I was thinking about getting a programmer, but unsure if it would decrease the longevity of the truck/injectors/etc.

[Idle_Chatter]

You're certain it's not pilot injection coincidental with the Allison shifting? Surely the dealer wouldn't be stumped by that!

[ckt]

I am not sure what pilot injection is. Could you please clarify that for me?