Uplander挂挡问题

[deberg]

有时挂挡不顺，稍给油感觉很硬的挂上，就像下面说的好像有人从后面撞上来似的。然后，开高速一段时间后到local，等红灯在启动感觉二档挂不上，车突突的震，要松一下油再给油才能挂上。网上搜了一下，跟下边这个人说的很像，难道真是solenoid出问题了？

“Since new, my van has sporadically had a few-second lag between reverse and drive when cold, but of course was told that this was 'normal operating procedure'. At 59K miles, I had the trans serviced only as a maintenance item. The dealer flushes, not only drains and refills, the fluid. Within a couple months, I had to add about half a pint of ATF, and noticed that every once in a while, pulling away from a stop, I got a sensation like someone had bumped me from behind. Also, lately, if the van has been driven on the highway for a number of miles, then you get off and drive in stop-and-go traffic, upshifts all of a sudden become hard. If you then stop for gas, or whatever, turning the car off, then back on, the shifting is as smooth as butter, just like when you start in the morning. This indicates to me it's something electronic, but I'm not getting a Service Engine Soon light on. Anybody else having this? ”

[deberg]

google了一下，说是变速箱油盘里的方形吸铁石不够强，铁屑影响传感器以致压力不足，需要更换两块园的rear earth magnet。

[reuben313]

在走走停停的开车情况下，第二档离合器磨损最大，因为慢速走走停停，要经常从一档到二档，从二档又到一档，尤其在dvp那种速度下堵车的时候。

离合器磨损以后，变速器需要较长的时间来完全锁定齿轮，松油门就是给变速器一个缓冲时间更平缓地变成二档。

老化的变速器可以把档位从空档变成前进档和倒车档来比较时间，你可能会发现从空档变成倒档的时间要比从空档变成前进档所花的时间要长得多。

所花的时间是从车子有前进或倒退的趋势开始算。 因为每次启动车的时候，倒档总是先受冲击，停车的时候，即使你不需要倒档，倒档也没有必要地又受一次冲击，所以倒档比一档磨损快（假定他们离合器设计寿命相同）；所以如果你是新车，可以试着每次发动车的时候在空档启动，如果不需要倒车，这样发动车就直接入前进档，延长了倒档的寿命。

[deberg]

不过GM确实在09年发了一个Service Bulletin对一系列的变速箱更换油盘里的磁铁。