Ad copy

I've been running a Hitachi mini-excavator since 2014. Last September a Hitachi dealer in Sydney quoted me $2,600 to swap four swing motor mounting bolts under the swing post on my ZX85. If you've ever owned a Hitachi ZX55, ZX85, or any of the smaller Hitachi mini-excavators past 4,500 hours, you already know which four bolts I'm talking about. My name's Mike. I'm fifty-one. I run a one-man landscape and small residential earthworks operation out of Mudgee in the NSW central west — wine country, ninety minutes north of Bathurst. Five days a week from March through November I'm laying drainage, building retaining walls, clearing residential building lots, and the occasional small commercial site-prep for the local builders. One man, one truck, one Hitachi ZX85, one trailer, one missus, two kids in school. The Hitachi is a 2014 ZX85US-5 short-radius mini-excavator with the Isuzu 4LE2 diesel and the standard boom-swing hydraulics. Faded Hitachi orange, clay-mud spatter from eleven NSW mud-seasons. 5,200 hours on the engine. I bought her in 2017 from a Wollongong civils contractor who'd over-bought during the LNG boom and was downsizing. My old man was a fencing contractor in the Mudgee area for thirty-eight years. He died in 2019 of complications from a tractor rollover at sixty-nine. He'd survived the rollover but a hip infection got him three months later. His brass-handled fencing rod sits on a peg above my workbench. He'd carried it on his Hilux tray for thirty-five years — for setting fence-line alignment over uneven country. The brass head has the dent from a Mudgee post he'd misjudged in '95. My missus Annie asked one time if I wanted to put it in the lounge. I told her no. It works by being on the peg. My shop is a 24x32 colorbond shed behind the house on three hectares my father-in-law sold me cheap in 2008. Concrete floor I poured myself in '10 with my brother-in-law. Saturday mornings I'm out there by half-six because landscape season means the Hitachi and the trailer are loaded for a Monday-morning dig by Sunday afternoon. Tea in a Stanley thermos Annie gave me when I started the business. ABC Central West on the radio. Annie runs the books from the spare room. She doesn't ask when I'll be in. She brings out toast around nine. The Hitachi ZX85US-5 is the most-bought-by-small-contractor mini-excavator in the NSW central west. Five thousand hours is normal. Eight isn't unusual. The machine is honest Isuzu diesel and Hitachi-clean hydraulics. But the ZX85 has one job every owner past 4,500 hours eventually faces: the swing motor mounting bolts. The swing motor sits under the swing post in the upper-frame, four M14 bolts holding it to the upper-frame casting. You can see them with a torch through the operator-side floor inspection plate. You cannot get a normal spanner on them. The hydraulic lines, the swing reduction gear housing, and the operator-platform mounting cross-member all sit in the way. The Hitachi service manual calls for the operator platform to be lifted to access them. Every Hitachi dealer in metropolitan Sydney quotes you for the platform lift. Last September I started hearing a metallic creak from the swing on hard turns. Pulled the floor inspection plate Saturday morning and torque-checked all four bolts. Two were way under spec — they'd backed off and worked the threads. The fix was new bolts (Hitachi-OEM M14 8.8) and a fresh torque to 260 Nm. The reach was the problem. Sidchrome 1/2-flex-head ratchet — I'd had since dad bought it for me when I started TAFE in '92. Folded at one-twenty Nm. The bolts needed two-fifty to break the corrosion. Stahlwille wobble extension on a deep socket. Walked off the head every pull. Caught it once. The second pull rounded a flat of the upper-rear bolt. Bahco kurze knarre. Four degrees of swing. The cross-member is right there. Four degrees on an eleven-year-old swing motor bolt is nothing. King Dick universal joint on a long extension fed in from below through the track. Deflected every pull. The socket left the bolt every time. A "ZX85 swing tool" I bought off the EarthmoverForum AU classifieds for fifty-eight bucks from a chap in the Hunter Valley. He swore he'd done his swing bolts with it. Maybe his weren't Mudgee-mud-cooked. Mine wobbled. The bolt didn't move. In the bottom drawer of my Sidchrome chest there's the row. A Repco swivel. A Gearwrench flex. Two Bahco universals. A Supercheap stubby. Combined: maybe three hundred bucks of tools that all flex when you load them. That's how I rounded the second flat on the upper-rear swing bolt. I sat down on the operator's seat looking down at the bolts for the better part of an hour. ABC Central West was doing the noon wine industry report out of Mudgee. Riesling crush was up. I sat through the crush. I called the Hitachi commercial dealer in Sydney Monday morning. Service writer said the swing motor bolt job was eight hours of book time at $165 plus the rounded extraction line plus the operator-platform lift. Two thousand six hundred bucks all up. He could fit me in three weeks Friday. I had a retaining wall job at a Mudgee winery extension the next Monday week. I told Annie at supper. She set her fork down and said, "Mike. Twenty-six hundred and three weeks for four bolts you can see through the floor inspection plate. No. That Hitachi is the wine country schedule." She picked her fork back up. In October I drove the Ranger with the Hitachi on the trailer up to the Hunter Equipment Expo at Newcastle Show Grounds — the biggest regional heavy-equipment expo in NSW outside metropolitan Sydney. Three days. Every dealer and every retired tech in the Hunter and the central west turns up. I'd been going six years. I parked the Ranger in the equipment-owner-op lot. Spent Friday walking. Saturday morning I came back and two machines down a man in his early seventies was leaned over the operator floor inspection plate of an '11 ZX85. Stocky, weathered Hunter Valley tan, full grey beard, faded Akubra. He had a short orange bar in his right hand. He reached down past the cross-member, set the head on a bolt I couldn't see, and broke it loose with one pull. His name was Frank. Seventy-two. Thirty-four years at the Hitachi Australia dealership in Sydney's Wetherill Park — primarily on small mini-excavators from the EX12 through the ZX-2 through the ZX-5 series. He retired in 2022 and started snowbirding the regional equipment expo circuit. He said the ZX55/85 swing motor bolt job paid for his Brisbane Water retirement house and his daughter's MBA. The Hitachi Frank was working on belonged to a chap from Cessnock named Dave who'd hauled it down with the same problem. Dave was at the parts swap. By the time Dave came back, all four swing motor bolts on his ZX85 were out clean and Frank was torquing the new bolts in. Dave stood there with a pie and said, "I had a quote for twenty-eight hundred at the Newcastle Hitachi." Frank said, "You won't be paying that." Then Frank looked at me. He said, "Walk to your rig." I walked. Frank brought the orange bar. He climbed up onto the operator platform of my ZX85. "Press on the end of this," he said. I pressed on the square drive. Inside the bar, something moved. Not flex. Not wobble. A chain. An internal roller chain that transferred torque through the offset angle. Frank reached past the cross-member and set the head of the BoltHero on my rounded upper-rear swing bolt. He pulled. The bolt came out on the first pull. The hex caught on the good flats and broke loose. Eleven years of central-west clay heat on a Hitachi swing bolt. One pull. We did the other three swing bolts the same way. I ordered one that night sitting in the Ranger in the Newcastle Show Grounds car park. getbolthero.com. Ninety-seven bucks. Frank said order direct — knockoffs on the EarthmoverForum classifieds look the same but don't have the chain drive. Hollow tubes that flex like the three hundred bucks of tools in my chest. I drove back to Mudgee Sunday. The winery retaining wall job went off Monday morning. The Hitachi swung tight, no creak. I've used the BoltHero twenty-four times since October. The four lower-front swing bolts I did anyway on a fresh Saturday. Three boom-cylinder shaft bolts I'd been avoiding for two seasons. Six aux hydraulic quick-coupler block bolts. Two Isuzu starter motor bolts behind the bell housing. Four blade-tilt cylinder pin bolts on a mate's ZX38U at Wellington. Three turbo Stehbolzen on Annie's brother's Ranger PJ at Orange. The accessory belt tensioner bolt my cousin's Pajero NS had stripped. The dealer wanted twenty-six hundred and three weeks for four bolts I could see through the floor plate. The spanner cost ninety-seven bucks. The math is simple. The hard part was driving four hours east to Newcastle Show Grounds and standing two machines down from a retired Wetherill Park Hitachi tech who'd done my exact bolts for thirty-four years. Annie asked me a couple Saturdays back if the Hitachi was tight on the swing. I told her no creak. She said, "Your old man would have wanted to know how you did it." She walked back to the kitchen. My old man's brass fencing rod is still on the peg. Six years since he died. Brass still has the dent from the Mudgee post. Frank and I text now. He sent me a photo last month of a '13 ZX55 he was helping a friend in Maitland put back together. Wrote underneath: "Same bolts. Same trick." The orange bar sits on top of the chest. Where I can reach it. If you own a Hitachi ZX18, ZX27, ZX55, ZX85, ZX135 short-radius mini-excavator, a Kobelco SK55 or SK75, a Sumitomo SH80, a Yanmar SV100, or any short-radius small-frame Japanese mini-excavator — you already know the bolts I'm talking about. The swing motor mounting bolts under the swing post. The boom-cylinder shaft bolts. The aux hydraulic quick-coupler block bolts. The Isuzu starter motor bolts behind the bell housing. You don't have to wait three weeks for Sydney about it. getbolthero.com Ninety-seven bucks. Order direct.