trans shift problem only at high rpm

[Cassanova122407]

whell, lets start i was screwing around doing pulls and i decided to go from a dig,at that time i brought my rpm up to redline and car would not shift into second almost like a miss it just grinded it only does it from like 6600-8000 rpm, dont know about any other gear because i couldn't catch second , daily driving is fine doing pulls all day first and only time i brought it so high in rpm band.
fwiw i have searched sense about 3:30 am et and couldnt find a problem like mine so i am posting my problem at 11:03 pm et thank you

 

[GRAVEDIGGER]

I'm assuming you have a stock transmission from looking in your profile, so unfortunately I'd have to say that is a sign of worn syncros. The 1-2 syncros are usually the first to exhibit problems, especially in the high rpms like you are describing. You might get a little better performance with switching to a different fluid. There are all kinds of threads about which fluid(s) to use, so I won't get into that. To totally rid the problem though, I'd have to guess that you would need to rebuild/upgrade the transmission to get a consistant high rpm shift. Good luck!

 

[Cassanova122407]

Thats what I was assuming but wanted other input,thank you for the response..