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M12 hits hard from park to reverse

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jesse View Drop Down
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    Posted: Sep/21/2017 at 3:16pm
1968 AMX 390 with M12 Borg Warner. Transmission shifts well in drive when driving down the road but from park to reverse it tends to hit hard once it engages. From park to drive it shifts good without hitting hard.
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FSJunkie View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote FSJunkie Quote  Post ReplyReply Direct Link To This Post Posted: Sep/22/2017 at 12:12am
They tend to have low stall torque converters. In other words, they transfer a lot of engine torque at low RPM. An engine idling just a few RPM too high can make for a lot of torque when the transmission engages into a driving range.

What is your idle speed? One tends to get a big clunk from these transmissions if their engine idles over about 700 in park. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DaemonForce Quote  Post ReplyReply Direct Link To This Post Posted: Sep/22/2017 at 7:33am
Originally posted by FSJunkie FSJunkie wrote:

They tend to have low stall torque converters. In other words, they transfer a lot of engine torque at low RPM.
Exactly this. This is the reason I prefer tuning my idle speed ridiculously low, like 450-600RPM range. Personally, I prefer that my transmissions engage really hard and fast or there tends to be problems.
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jesse View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jesse Quote  Post ReplyReply Direct Link To This Post Posted: Sep/23/2017 at 2:49am
Yes i would say about 900 rpm or more.
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