Center Joint Seal Kit for Construction Machinery 31N4-40951 Excavator. Premium quality hydraulic seal repair kit for construction machinery from topsealkit, delivers reliable sealing performance, superior pressure resistance, and precise compatibility for R140W-7 R170W-7 excavators. This aftermarket premium center joint seal kit meets or exceeds OEM specifications, constructed with high-quality materials to withstand harsh working conditions in construction, mining, and civil engineering sites.