Descrizione
When a machine loses hydraulic power, the first suspects are the pumps. On these excavators the component that fails quietly and destroys pumps is the one in between: the drive housing that transmits crankshaft torque into the pump train. It is a mechanical part with bearings and gears in oil, and it is repaired far too rarely until a second pump has been ruined.
What this assembly does
11128611 is the power take-off group bolted to the engine, sometimes listed as a bearing housing or pump coupling. Its gears or shaft carry the drive to the main hydraulic pumps and, on this configuration, to the fan drive pump as well. Volvo’s own parts literature for the related assembly describes it as the power transfer component between the engine and the pumps on the EC360 and EC460 with the D12D engine.
Symptoms that this housing, not the pump, is at fault
- Two pumps fail in sequence. This is the classic signature. A new pump runs for a few hundred hours and then dies, because the drive coupling in the housing has worn and is no longer transmitting torque cleanly.
- Metal in the oil with a sound pump. Splined or gear wear inside the housing sheds material straight into the pump feed.
- Noise at the pump end with normal pressure: a worn bearing allows the pump shaft to run off-centre.
- Oil leaking at the interface between engine and pump, often mistaken for a pump seal.
If a machine has already lost one pump, inspect this housing before fitting the second. Our guida alla diagnosi dei guasti dell'azionamento pompa e della scatola di trasferimento covers the inspection, and ispezione dell'ingranaggio di trasmissione shows what wear looks like.
Montaggio
Check the drive gear backlash and the bearing play before installation, fill the housing with clean oil, align the pump splines without forcing them, and confirm the sealing surfaces are free of scoring. Flush the hydraulic circuit and change the filter elements, because whatever the old housing shed is still in the oil. Target ISO 4406 18/16/13 or better.
Ordinazione
Send the machine model, the engine designation and the serial prefix. The housing differs between engine families, and a D12D machine and a later engine variant will not share this part. Minimum order one piece. Three to six month warranty on new aftermarket units as stated on your proforma invoice; photographed against your order before the wooden case closes, delivery 5 to 8 working days from payment subject to stock. The EC380D and EC480D version is 15054375, and this section covers pump drive housings rather than pumps or motors.
