Check this link on TSB's (Tech Service Bulletin):

https://www.crossfireforum.org/forum...data-tsbs.html

One or both of the following TSB's may prove helpful:

TBS: 9-Mar-04 - 21-002-04 - Manual Trans - First Gear Disengages During Normal Acceleration
TBS: 6-Jan-05 - 21-001-05 - Manual Trans - Gear Grind Sound When Shifting

The shifting on my Manual 6 is solid and clean and never pops out of 1st on normal or hard acceleration.

I'm not sure if there is a possible linkage adjustment that can be made, but if there is, maybe someone will chime in...

Also on the Manual there is no easy way to check on low fluid (lack of dip stick), and it requires a visual inspection.

Might not hurt to inspect tranny for possible leaks...