Seven hardened drivers and two handles sized for the bushings in GM 6L80 and 6L90 six-speed transmissions, 2006 and up.
Searching for a 6L80 bushing driver usually means you are mid-rebuild on a 2006-up Silverado, Sierra, Tahoe, Yukon, Escalade, Hummer, Camaro or Corvette six-speed and just found out that nothing in a general-purpose bushing set fits right. This tool kit is nine pieces: seven bushing drivers and two drive handles, hardened solid steel with a black finish, cut for the GM 6L80 and 6L90 and listed as a replacement for 104bdmk and 6L80-Tool.
The reason this unit needs its own drivers is how closely the bushing sizes are spaced. Going by the published dimensions for the Sonnax 6L80/6L90 bushing kit, the 2-6/3-5-R hub front bushing sits in a 1.600 inch bore and the hub rear bushing in a 1.590 inch bore, only a hundredth apart. The pump bushing bore is 1.994 inch and the front center support bore is 2.018 inch. The 1-2-3-4/3-5-R drum bushing is the largest at a 2.346 inch bore, and the 4-5-6 clutch drum bushing is the smallest at 0.819 inch over a 0.685 inch shaft. A driver that is even slightly undersize lets the bushing tip as it starts; one that is oversize rides on the bore edge instead of the bushing. Each driver here pilots in the bushing ID and pushes on its face so it stays square, and the smallest one is sized for that tiny 4-5-6 drum bushing, the one that tends to get ruined with a punch.
Bushing wear and clutch wear look alike from the driver's seat, and both get blamed on fluid. Start with the scan tool and a pressure gauge and work through the pattern in our 6L80 Corvette common problems guide or the truck and SUV version in 6L80 Escalade shift problems; the diagnosis is the same unit regardless of body. If pressure holds in some ranges and drops in others, the leak is in a rotating circuit. Teardown confirms it: measure each journal and bushing, and compare clearance to the rebuild manual for your unit.
Listed for GM 6L80 and 6L90 six-speed transmissions from 2006 and up, behind Chevrolet, GMC, Cadillac and Hummer applications. The 6L90 has a longer case and heavier internals than the 6L80, but this kit is listed for both. It replaces 104bdmk and 6L80-Tool. It is not listed for the 6L45 or 6L50, and it is not for the front-drive 6T family. Bushings are not included. To be sure of your unit, read the RPO code on the service parts label (MYC for 6L80, MYD for 6L90) or send us your year and VIN. Browse the rest of our parts for this transmission on the 6L80 collection page.
Knock or pull the old bushing out without nicking the bore, then clean it and look for a scored or wallowed surface; a bore that is out of round needs more than a new bushing. Choose the driver by test-fitting the pilot in the new bushing, not by eye, since several sizes are within hundredths of each other. Lube the bushing lightly, align any oil hole with the feed hole in the housing, and press it straight until it seats. Sonnax recommends an arbor press over a driver and hammer for precision bushings, so use the handles with a hammer only where a press cannot reach. After installing, spin the mating shaft to confirm it turns freely before the case goes back together. Pair this kit with a BorgWarner 6L80 friction clutch module kit if the frictions are burnt, and fill with full synthetic Dexron VI ATF once the unit is in.
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The 4-5-6 clutch drum bushing. In the Sonnax 6L80/6L90 bushing kit it is listed at a 0.819 inch housing bore over a 0.685 inch shaft, and this kit includes a small driver for it.
Yes. The kit is listed for both the 6L80 and 6L90 six-speed transmissions from 2006 and up.
No. It is seven drivers and two handles. Use the bushings from your rebuild kit or a 6L80/6L90 bushing kit.
Test-fit the pilot inside the new bushing. It should slide in snugly without slop, and the shoulder should cover the bushing face without touching the housing bore.
Replace the seal rings, gaskets and any burnt frictions at the same time, and inspect the shaft journals for scoring. A worn journal will wear a new bushing quickly.
