Tranny noise during shift

[ejs999]

The other day I thought it was a coincidence, but two nights ago I heard it twice so I know it's not. When I was shifting from 2nd to 3rd it sounded like I was running over a large piece of thin metal (almost crackling) on the road. The trans seems to be fine other than that. One time the other night (same night) it sounded like a bunch of rocks rattling around in a metal container during the 2nd to 3rd shift.
The noise is inconsistent and I've noticed it more during a hard shift.

All of the linkage was replaced within 10k and a visual inspection 1k ago of the linkage was fine.

Any ideas?

[DJB]

Check the fluid level, and do it soon.

My first symptom of low transmission fluid was a bit of grinding when shifting from 2nd to 3rd, as if I had missed the shift. It very quickly progressed to not being able to shift to 3rd.

I had checked the fluid level regularly, but must have been fooled by residual oil around the edges. There was only a few ounces left when I drained it.