When I am starting in 1st or reverse under about 2k the car bucks. I want to say that the tranny cross member is hosed. What parts do I need to replace this?

 

Trans mount:
http://www.mazdatrix.com/g3.htm

I'd check very closely to see if the mount is a gonner. The center support isn't designed to support any weight, so it may be pushed down as most probably are at this time. If you're going to replace the crossmember, replace the 2 blocks also.

 

Sounds like more of a TPS or clutch issue to me. Probably best to check the adjustment of the TPS and the condition of the clutch (not easy...) first.

 

Sounds more like the U-joints in the driveshaft. I used to have a similar problem where the car would shudder when under very light throttle and low RPMs. It was most prevalent when starting on hills (such as waiting at stop signs uphill). That driveshaft was replaced years ago and it the problem went away.

 

any transmission shop can replace the u-joints on the t2 driveshaft? The clutch is a brand new oem replacement piece (beck-arnley) we just bled the clutch line and let it roll. Should I just follow the FSM steps for adjusting the clutch?