Gonna have to be fast with that last move because just the slightest hesitation and the collar will weld up on the first side & you will not get it across. Just sayin from my many oops’s…
Yea, I was thinking the same thing; what if the collar is hard to move, and the cement sets up before I get it across the gap? That would suck. Will look in to using the gray cement recommended by Moonshiner.
Yep, will be doing that.
They have a new telescoping slip coupling that I will try next time I have a repair. The telescoping feature allows it to slip in a lot easier. Also, the cut you make isn’t as critical. I don’t know if they make 4 inch ones for the OP or not.
Not to nitpick, but it’s a combination, not a wye. Also, we usually put
two of them back to back so you can clean out in both directions.
If in a pinch…hose and hose clamps. 
One should never snake a drain going from the outside of your home towards the house. Your waste/sewer drain should flow downhill to your septic tank or sewer connection, and that’s the way you would push it to unclog a stoppage. If you snake going into the house you run the risk of pushing the stoppage into and up out of your toilet, tub/shower, sinks, etc.
Or do it the redneck way: just clean the outside of the PVC and put a couple layers of duct tape around it, then bury it again. Plant some veggies above it; they’ll grow well.