Spent the day working on the 2WD 4L80E transmission, modifying it to work with the Atlas and factory GM adapter. Far as
adapting the 4L80E to the Atlas, you can either buy a $250 adapter from Advanced OR use a short factory adapter for the 4L80E to NP241, cut the shaft and bolt up an Atlas. The 2WD also has two speed sensors inside the trans (versus the 4WD version), so you don't need one built into the adapter. There are two versions of the factory GM adapter... steel (hard to find) & aluminum that currently costs $65. I couldn't find a steel adapter, so aluminum it is!
Aluminum-
https://www.amazon.com/gp/product/B010GNWLIO/ref=ox_sc_saved_title_1?smid=ATVPDKIKX0DER&psc=1
I had to chop 3.5" off the output shaft of the 4L80E and verify that the shaft didn't bottom out on the Atlas input shaft. You can do some serious damage if the shaft is bottoming out in the t-case! I used a cutoff wheel, carefully protected the transmission from metal shavings and went to town. I cleaned up the cut with a flap disc and added a bevel to the shaft splines so it slides into place easily.
Once that was done, I bolted up the adapter and then the Atlas. It all looked good, so I bolted up the aluminum 5.3 mock up engine and rolled the engine/trans/t-case into place to mock it up and see where the floor needs to be cut for a flat belly.
With everything in place, it doesn't look like I'll need to do too much cutting to get a flat belly with the big 4L80E and Atlas. The additional 1.25" body lift from the Artec Boat Side body mounts really helped. Maybe 1.5" more clearance at the tub under the drivers seat and transmission hump and I'll have it. I also removed the piece of sheetmetal that the factory seat mounts tie into using a spot weld cutting bit, as the seat mounts won't be getting used anyway. That gives me better access to the floor that needs to be cut and raised.
So a little whining.... both UPS and FedEx have screwed up my recent parts orders. My Motobilt frame pieces were supposed to arrive yesterday (they were in Denver yesterday morning). Delivery has been pushed back until next Tuesday and I won't be home. I really wanted to start working on the frame setup and see how it will all fit together. Also, I ordered a
Barnes 4WD TJ flat belly skidplate, but apparently FedEx has lost it. It was supposed to arrive last Tuesday, but the tracking hasn't been updated and they're saying no delivery ETA is available.
