Im in the process of installing a SC stg IV and wondering how i can check to make sure the mainshaft is still aligned without removing the rear housing agian? Im pretty sure i didnt move it but i just want to double check. Thanks!

If you started by doing the rear (C4s) and got it lined up as you put it back together, then flipped the trans and did the front (C3s and C1/C2 drum, pump mods, ect) than as long as you didn't pick up and turn the intermediate shaft it should still be lined up the way you left it. If for some reason you think you may have messed it up than putting the back end back up (with the front end completely assembled) and taking off the rear housing is going to be the only way to do it.

Theres no way to measure or indication?

would the bellhouseing still go on with no gap if the mainshaft wasnt lined up?

You can lift up on the shaft slightly to make sure it is bottoming out. If you can't lift it, you caught the edge and need to pull it apart.

Second guessing it while you still have it out is easy.......second guessing and putting it back in the truck wouldn't be smart......

how much does it take to lift it out to far? 1/8"? 1/4"?

410-960-6015

would the bellhouseing still go on with no gap if the mainshaft wasnt lined up?

IIRC the bell housing will not go back on with no gap if the intermediate is not engaged in the spines of the spacer ring. But it can be engaged in the splines and still not lined up properly - the hole in the intermediate shaft should be aligned with one of the notches in the spacer. If the bellhousing won't go on without a gap I would loosly bolt it on, flip the trans over (on a stand, not on the ground), take off the extension housing, tighten the bell housing up, align the spacer on the shaft and put the extension housing back on.