反鼓磨损：一个4L80-E的真实故事

一辆汽车经过一次修理后，在路上行驶了将近一年后进入了一家商店。这是一款新款4L80-E型（平滑带）带有“禁止倒车”的换档注意事项。需要注意的是，这辆车是一家公用事业公司使用的超负荷卡车。

这个传输当然，带子明显烧坏了，也有一部分损坏了，所以就把它换了（没有人太注意鼓，因为它看起来很“光滑”）。安装后，卡车进行了路试，再次失去了早期的逆转。现在沮丧，商店删除了传输和果然，乐队再次被烧毁！啊，你有过这样的经历吗？所以，这里的商店是第三次（没有赚很多钱在这个工作），最后开始测试，试图找出为什么这个问题不断发生。

变速器被重新安装到车上。安装了一个压力表，果然，反向的压力非常棒（失速时远远超过300磅/平方英寸）。第二步（电气拔下变速器）被忽略了，但在这种情况下，它的工作很好，因为问题确实发生在装置内部。拆下油底壳以安装专用工具，以便在机架上进行测试时机械锁定带，但仍然不能反转！再次，变速器被拆除，以便更仔细地检查。在工作台上，安装了压缩钢带的专用工具，以便看到钢带，这时车间发现钢带无法压缩到滚筒上（钢带两端相互撞击，防止钢带夹在滚筒上）。这辆超载的车辆确实有光滑的钢带，而且钢带的表面磨损严重（由于超载造成的对钢带的磨损而导致尺寸过小），以至于钢带无法抵住钢带。解决方法：把乐队和鼓都换了，瞧——别再说“不准倒转！”

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建造室的注意事项和关注事项

Keep in mind, when changing parts and/or interchanging parts around the band and drum, band travel is typically set at around 3/16". There is a factory tool that can be used to set this commonly known as a "go/no-go gauge." If you do not have the factory tool, use a homemade one made from a servo cover, it works great. To make this tool, drill through the center of the servo and weld a nut on the outside (on top of the drilled hole). Using a bolt allows the servo piston to be held mechanically. Drill a second hole in the cover off to the side so you can measure the band's travel on the bench before installing the valve body (图1，左侧工具）。根据需要调整。

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维修过程中是否有明显磨损？

4月初穿鼓l80-e低/反向乐队和drum assemblies is easy to identify as the grooved lining in the band typically leaves marks along the surface of the drum (like railroad tracks). The smooth-lined band (used in the late 4L80-E) does not do this. It typically wears a smooth area around the full surface of the drum and is harder to see while building this unit. Unless you are specifically measuring the O.D. of the drum or looking at it with a gauging tool during assembly to determine the wear across the drum, it is easily missed. Always take the time on the bench to make sure during the assembly that the band ends do not touch with the servo applied, and that you do not build-in this issue. It can easily be checked and prevented.

特别感谢伊利诺伊州艾迪生的A-C Transmissions的多米尼克·皮特兰托尼奥，他把这个问题提交给TASC，并再次与我们分享。多米尼克，报告和修理都很好！谢谢！

记住诊断规则：将液压、电气和机械回路分开。按顺序进行，一次一个，以获得完整准确的诊断。有关此诊断过程的详细讨论，请阅读用4L80-E诊断难以捉摸的无反转.

兰德尔施罗德is a Sonnax technical specialist and a member of theTASC Force®（技术汽车专业委员会），一组公认的行业技术专家，变速器重建和索纳克斯工业公司的技术人员。