on the shaft for the 5th gear nut their are grooves, i've found that when re-installing the nut after you have torqed the heck outta it with a hammer, take yourself a chissel or flat head and find the point on the nut that is in line with the grooves in the shaft. take the chissel and make an indention on the nut down into the grooves of the shaft. this should keep her from baking off on you. also, make sure that you check the springs and the and the little pieces they push out (forgot what to call them) on the clutch ring to make sure it's functioning properly.

I would suggest a full spline output shaft and a nut and gear.



RX7, this problem is the synchro on the fifth gear, its on the counter shaft and the assy is held on with a snap ring the synchro can be changed with tranny still in place just drop cross member and pull tailshaft housing off.The synchro runs around twenty to thirty dollars. Hope this helps.

Here is pictures of what the "clunk" noise is.

yep thats broken :ouch: Mine looked the same on the shaft splines (all rounded off).But never seen a gear break!! I can check to see if I can get a main shaft for you it will be monday or tuesday tho.

when i slide the 5th gear onto the splines on the shaft, i get a little bit of movement. Is this normal or are the splines wore out on the shaft.. I checked the donor 2wd trans. i got the 5th gear from and it has the same amount of movement. Any thoughts??

That movement is why the nut comes loose shaft is no good.

Thanks, it's kinda what I figured, I wish I would have known about it when I did the 5th gear nut though