Yeah, mine does the same thing, I've made it go into lower gear by hand, but the rpm's did go up pretty high. The red line on the Suzuki for rpm's is pretty high and it will hold up pretty well, but one time, I did break a piston on a Samurai for revving it up for a really long time trying to keep 80mph on 4th gear. The piston broke in Mexico and it made it all the way to Houston at good speeds still.

1985 Toyota 4x4 4Runner. 1989 Suzuki Sidekick 4x4.