Southern States EV2 bearing refurbishment and upgrade.
The operating-shaft bearing is the failure we see most on the Southern States EV2. It seizes from corrosion, not wear, so grease never fixes it. We refurbish it with a 316 stainless shaft, a machined brass lock nut, Viton O-ring seals, and sealed stainless bearings, all machined in our Palm Harbor shop, and return it to service instead of scrapping the switch. Ship us the bearing, ship us the switch, or have our field crew pull it and reinstall it.
A corrosion problem, not a lubrication problem.
Three mechanisms act at once, and coastal salt humidity feeds all three. Grease does not fix any of them, because grease is not a seal and the joint keeps getting wet. The rebuild works because it removes the water and the parts that jam, not because it moves the metals closer on the galvanic series.
The oil-impregnated felt gasket loses its oil charge over the first decade. Dry felt is hygroscopic, so it stops sealing and starts drawing moisture in, holding it against the bearing and shaft. The stainless shim over it looks like a seal long after the real seal has quit.
A small aluminum nut against a large steel shaft is a modest galvanic couple, about two tenths of a volt, but the area ratio concentrates the attack and the wet thread crevice never dries. Aluminum corrosion product occupies several times the metal it replaces, packing the threads until the nut is locked by oxidation.
The stock bearing has stainless races and balls but a carbon-steel cage. Water reaches it and the cage rusts and binds the rolling elements. Judge the bearing by the balls and races alone and you miss it, because those still look fine while the cage behind them has failed.
Full teardown detail, field signs, and photographs are in the deep-dive: EV2 bearing seizure, causes and field signs →
We attack the water, then the metals that jam.
Galvanic corrosion needs three things at once: two dissimilar metals, an electrical path between them, and a continuous electrolyte bridging both. In a threaded assembly the metals are unavoidable. The electrolyte is not. Two Viton O-rings, above and below the bearing housing, keep water out of the thread crevice, and sealed stainless bearings keep it out of the rolling elements. A cell with no continuous electrolyte does not run, whatever the potential difference.
Then we change the part that actually jams. A machined brass lock nut on a 316 stainless shaft still forms a couple, but brass corrodes slowly and its corrosion product does not expand and lock the threads the way aluminum hydroxide does. Dry joint, slow metal, no jamming product. That is why the rebuilt assembly is designed to come apart with a hand wrench decades from now and the original comes out under a press.
Replaces the mild steel shaft that rusts and sheds abrasive particles onto the bearing below.
Replaces the aluminum nut. No expanding oxide, stays serviceable with hand tools at the next visit.
Replace the felt gasket. Viton does not absorb water and has no oil charge to deplete.
No ferrous cage left inside to corrode. The enhanced upgrade goes fully stainless.
Standard rebuild, or enhanced for the coast.
316 stainless shaft, sealed bearings dimensionally equivalent to the originals, machined brass lock nut, and two Viton O-rings, on the reused cast steel housing. Addresses all three seizure mechanisms.
Adds fully stainless bearings, a machined rain shield press-fit below the housing to shed water off the shaft, a Mobil XHP222 grease fill, and a zerk fitting so the bearing can be greased in the field without disassembly.
When the insulators, contacts, or linkage need work too. Full shop teardown, the bearing upgrade above, contact reconditioning, alignment, function test, and documentation, returned ready to install.
The bearing is one subassembly of the EV2.
The EV2 is a gang-operated air-break switch, and the operating-shaft bearing is the part that fails first. When the contacts, the linkage arm, or the gear operator need work at the same time, the bearing upgrade is one line item in a full switch refurbishment. See the complete scope, contacts through operator, on the Southern States EV2 switch page.
EV2 bearing questions.
Why do Southern States EV2 bearings seize?
Three things act together, and coastal salt humidity drives all of them. The oil-impregnated felt seal dries out and then wicks moisture against the bearing. An aluminum lock nut corrodes against the steel shaft, and the aluminum corrosion product expands and packs the threads until the nut is welded in place. And the carbon-steel cage inside the otherwise stainless bearing rusts and binds the rolling elements. The result is a switch that gets stiff, then will not complete its travel. It is a corrosion problem, not a lubrication problem, which is why grease does not fix it.
What does the EV2 bearing refurbishment change?
The rebuild removes the water and the parts that jam. A 316 stainless shaft replaces the mild steel one, a machined brass lock nut replaces the aluminum, two Viton O-rings replace the felt seal, and sealed stainless bearings replace the open steel-caged units. The Viton seals keep the electrolyte out of the joint so galvanic attack has nothing to run on, and brass does not throw off the expanding corrosion product that locks an aluminum nut onto a steel shaft.
What is the difference between the standard and enhanced bearing upgrade?
The standard upgrade uses a 316 stainless shaft, sealed bearings dimensionally equivalent to the originals, a machined brass lock nut, and two Viton O-rings on the reused cast steel housing, addressing all three seizure mechanisms. The enhanced coastal upgrade adds fully stainless bearings, a machined rain shield press-fit below the housing to shed water off the shaft, a Mobil XHP222 grease fill, and a zerk fitting so the bearing can be greased in the field without disassembly.
Background reading.
The full teardown, the three failure mechanisms, and the field signs that tell you a bearing is on its way to seizing.
A seized EV2 bearing torn down, the failure documented, and the assembly rebuilt with the stainless-and-Viton upgrade.
The refurbished and upgraded EV2 bearing as a machined part, ready to order for your own installation.
We respond within one business day with a scope, a price, and a lead time. Photos of the bearing, the shaft, and the lock nut help us scope it accurately. A stiff bearing caught now is a shop repair, not an outage.