止损4T60-E，4T65-E壳体磨损，带滑动和破损较长的伺服销

GM 4T65-E上的破碎或燃烧的前向频段传播在拆除过程中，不是一个罕见的事情。大多数Rebuilders都看到了指向共同失败的公告和技术文章，并通过EPC具有间歇性问题，压力升高导致起飞的滑动或喋喋不休，这可能是前向频段失败的最大贡献者。

I previously owned a ’08 Grand Prix and, when hot, the EPC would hang up and cause intermittent no-pressure-rise conditions. I would always know that if I parked the vehicle after a long drive, then got back into the vehicle after a 20-minute set and put it in Reverse to back out of a parking spot, that I needed to wait for a 1,001…1,002 count when selecting Drive for the forward band to fully engage. If I did not give it the 2-second count and stepped on the gas before it was engaged into Drive, engine RPM would race up, the forward band would shudder then slam in, almost like a Neutral drop!

在这里发生了什么，因为选择器被置于驱动器时，TCM正在尝试提高压力，但车辆处于中立状态。一旦弹叉EPC电磁阀赶上而去，压力几乎会最大化，导致前向频段最终啮合时，引起猛烈轴。从中立状态撞击到驱动器，这样可以肯定会打破一个乐队。在大修期间更换EPC并验证或修复压力调节器和扭矩信号孔将处理此问题。

然而，还有一个需要注意的区域，这是前进的伺服引脚长度。我相信许多重建者在安装新乐队后看了乐队清关，并注意到它相当大。为了帮助关闭此差距，Sonnax现在提供扩展的长度前进带伺服引脚，零件号84571-01K，用于4T60-E和4T65-E应用。典型的伺服引脚行程约为.400“，因此Sonnax伺服引脚（在大约200”的“更长”中）将切成两半，大大帮助占用额外的频段间隙。

由于伺服引脚的情况下孔也可以穿，因此Sonnax引脚还包括两个密封环，以防止泄漏超过伺服销。

Addressing pressure control issues and installing the new Sonnax servo pin will help speed up the engagement into Drive, as there will be much less travel for the forward servo to fully apply the band. Focusing on these two areas will help prevent customer complaints and repeat broken or burnt-up forward band issues.

Jim Dial是Sonnax技术专家和Sonnax的成员Tasc力量（技术汽车专业委员会），一批认可的行业技术专家，传输Rebuilders和Sonnax Industries Inc.技术人员。