Thread: engine/trans shake when burning out

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I switched the poly link mounts to heim joints because I thought I was getting flexing back and forth in those maybe, so now they are solid as a rock.
I had the driveshaft made custom, and there is no vibration even at 65 mph, which is the fastest I've ever turned it, so as spears said I def don't think there could be a balance issue.
I would hope the shaft is not wrapping, but I guess I can't be positive about that. The only thing is, I would think there would be less torque on the shaft after the tires cut loose than if I kept them planted, and there are no problems at all at full throttle in 1st gear as long as they don't slip.
I did try a burnout here at work, concrete plant, which is like wet conditions because there is a coating of dust on the pavement surface that makes them really slippery, and had the same results.
I wish I could mount a camera under the car to watch the trans when this happens.

You said it's a tri 4 link, is that a 4 link with the two top bars close together like a Chevelle or is it a tri link (1 upper bar)?
What's the IC of the rear suspension? Could be the 4 link / tri link geometry is off & only shows up under power. Bottom bars at the wrong angle? Just thinking out loud. Hard to tell without watching it and seeing what the set-up looks like. Could be the rear end is binding & unloading as the tires spin, Causing a clockwise/counterclockwise rotation of the rear end housing. That may not be noticed from outside the car. I don't know if I'm explaining what I mean right.

I think pro is on the right track if the rear is to tight it could be trying to go both ways at same time trying to remember where I read a post on just that topic. Might have been right here

it is a triangulated 4 link, so I have the two top bars angled inwards and the bottom bars are parrallel. I also added a panhard bar last month when I was attempting to solve the problem.
I'll find the pics I have when I get home of the rear before I put the bed on the truck so you can see it clearly, and I'll also post those video's if I can figure it out, but I've watched those things many times and I can't see any movement at all of the axle.