Screeching when Autostick in neutral

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W8 4 ME
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Joined: Thu Aug 24, 2017 1:05 pm

Screeching when Autostick in neutral

Post by W8 4 ME » Thu Aug 24, 2017 2:15 pm

Hi all -

We have had a 1970 KG for 10+ years and it's always been very dependable. Since a recent service, though, we started getting a loud screeching noise when the Autostick is in neutral. Put in any gear, and it goes away. Any ideas?? My mechanic is out town so I can't ask him!

It starts happening after you've driven about a mile or so.

Here is a short video where I shift a couple of times:

https://www.youtube.com/watch?v=GRSflaDsn9M&feature=youtu.be

Crawford

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FJCamper
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Re: Screeching when Autostick in neutral

Post by FJCamper » Fri Aug 25, 2017 10:32 am

Could be a leak on the vac canister. Here's the reasoning for that.

When you shift an autostick, there is a microswitch at the base of the shifter that sends a signal to a big vacuum can beside the transmission that pushes against the clutch lever just as if it were your foot that did it. An autostick is really an auto-clutch. You have a 3-speed manual transmission, and a standard clutch (with disk). The automatic part is the electrical switch in the shifter, the vac can, and a device called a torque converter between your engine and your transmission.

The torque converter is the part that needs automatic transmission fluid. It allows you to sit at a stop light, in gear, and not move forward until you rev the engine and make the torque converter engage the actual mechanical clutch.

Your engine supplies vacuum to the vac can. The can and its hose connections can leak. A vac leak can make a whistle or a screech sound as pressure is vented.

You say yours screeches when you shift to neutral. You are causing the vac assembly to activate when you do that, and there is a moment when the vac leak is exposed. It would be in its early stages since it's just leaking now at shifting.

I hope you have something cheaper and more simple actually wrong. Good luck.

FJC

W8 4 ME
Posts: 2
Joined: Thu Aug 24, 2017 1:05 pm

Re: Screeching when Autostick in neutral

Post by W8 4 ME » Fri Aug 25, 2017 12:23 pm

Thanks for the info!

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