Can't remove bearing carrier plate from transaxle on case 580c

Rust and dried crud bonding the O-ring to the housing is by far the most common cause of a stuck left-side carrier plate on a 580C — the plate has an o ring that seals to the housing and trans axle, and it more than likely has some crud and rust holding it. That's normal even when the right side came out clean; the two sides don't always corrode evenly, and the left side carrier catches more moisture in a lot of these machines.

Before you pull harder, confirm you've actually got every fastener out: the brake backing plate has a countersunk screw that's easy to miss if a previous repair left it out, and it takes an impact wrench to remove since it's often rusted in. Missing that screw is the single most common reason guys think the plate is "stuck" when it's actually still bolted.

Once you've verified the fastener is out:

1. Break the rust bond at the weep/drain hole first. Use pry bars to work the side plate loose, keeping track of the shims between the plate and housing, and you might have to start with a chisel at the weep hole to get it started.
2. Pry evenly around the perimeter, not from one spot — the carrier bore is a precision fit and prying from one side cocks it and makes it bind worse.
3. Penetrating oil in the weep hole and around the visible seam, give it 15-20 minutes, then work the chisel/pry bar again.
4. If it's moved even a little (some report it creeping out roughly .1" before hanging up), don't force it further with wedges. At that point the plate is usually hanging on the dowel/register fit rather than the O-ring, and continued prying risks cracking the casting ear or bending the plate.

One thing to watch closely: pulling the left carrier lets the differential/crownwheel assembly shift and drop slightly once bearing preload is released, which is exactly what makes reassembly tricky. Guys commonly lock the brake on the opposite side before pulling this one, to keep the cross-shaft from walking out of position while you're working it loose. Keep every shim pack you find and put it back exactly where it came from — those shims set backlash and bearing preload, and mixing them between sides is the classic mistake that turns a seal job into a full teardown with a dial indicator to reset rolling torque.

If it still won't budge after chisel-and-pry with penetrating oil, next step up is a slide-hammer puller threaded into the two bolt holes in the plate face, pulling square and steady rather than impact-shocking it, since shock can crack the thin casting flange.