Manual Transmission - T56 Preload question

Just a quick question when measuring the preload on the main and countershaft. When measuring, do you install each one separately and then measure each individual shaft, or do you install both the mainshaft and countershaft and check each shaft while both are meshed together? I rebuilt my trans 6 years ago when I was 18 and I have a feeling I set it up incorrectly. I have to take the trans apart again now and wanna be correct on it.

Thank you,
Jarett

main and counter can be checked at the same time.

Yes, you can do the main and counter at the same time. Get them shimmed properly and attach the main case. Then do the counter extension.

In theory, you should check the Countershaft preload and shim it before checking the mainshaft. In practice, the deflection of the case from the preloaded Countershaft is less than 0.001" and most rebuilders are shimming the countershaft and mainshafts tighter than spec already, so it doesn't adversely affect the performance.