Grinding noise when i first accelerate

[SwedishPhish]

I cant figure it out. Its not my diff or my tranny. When i give the motor full power the gears make a grinding noise, but only when i first hit full throttle. There was no noise like that the last time i used my truck, a week ago. I havent touched the tranny since so i dont think its that. I re-lubed it so it cant be dry. My mesh seems to be set correctly. Any ideas?

[gubbs3]

A grinding noise car only be made from gears and diffs so if you are 100% sure its not the diff the gears must be skipping. I've seen it happen before where the motor plate can flex enough to open up the mesh and let the teeth skip without totally messing up the gear.

[Nairb]

Dude, it's you diff slipping. Tighten it down a little and/or loosen your slipper a bit. Hopefully, you haven't already ruined your diff balls by creating flat spots on them.

[DJ BlendeR]

What truck do you have? And Nairb, I know that you know more than me, however I dont think it is his diff because I had this problem when I had my diff removed. I have XXX-T, and I also had it make the noise only a week after my last use of it. My LHS said not to worry about it and when something breaks fix it then.

[Gutter Ball]

Check your motor screws! I stripped one of mine(don't know my own strength!) and my XXXT made an awful screeching sound when I first hit the throttle. The motor was pivoting a bit during acceleration. Put in a new motor, didn't tighten as hard and the screeching stopped. The other day, my B2 was making a "clicking" sound when I hit the throttle. Thought a rock got into my tranny. Took it apart and found my diff bearings were "warped"! They didn't roll very nicely :/ My thrust screw was also stripped. Good luck!