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Old 02-27-2021, 04:14 PM   #1
lux
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TH 400 help

My TH400 is not kicking down.
I have a Lokar kickdown switch all set up correctly.
- I tested for 12 volts at the trans kick down connector. I put my volt meter on the spade and had my wife push the gas peddle down. At about 3/4 throttle I see 12 volts at the trans kick down spade.
- I then tested to see if I could hear the solenoid in the trans. I ran a wire from the battery to the trans kick down spade, When I made contact I could hear the solenoid in the trans. I did it that way so I could eliminate all other noise.

When I'm driving and in 3rd, I go to wide open throttle and it does not kick down to 2nd.

The trans is new but I bought it second hand so I don't know if it's modified.

Thanks for any help.
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Old 02-27-2021, 08:52 PM   #2
kwmech
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Re: TH 400 help

At what speed are you trying to get passing gear?
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Old 02-27-2021, 09:56 PM   #3
lux
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Re: TH 400 help

Quote:
Originally Posted by kwmech View Post
At what speed are you trying to get passing gear?
I've tried at a lot of different speeds and it won't kick down at any speed.
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Old 02-27-2021, 11:11 PM   #4
Getter-Done
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Re: TH 400 help

Is the Governer working freely?
Modulator valve okay?









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Old 02-28-2021, 12:27 AM   #5
lux
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Re: TH 400 help

Quote:
Originally Posted by Getter-Done View Post
Is the Governer working freely?
Modulator valve okay?









.
I have the vacuum modulator hooked up correctly, but I don't know how to test it?
You have to educate me on the governor, I don't know anything about it.
I was under the impression that the kick down solenoid was what down shifted the trans.
Thank you.
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Old 02-28-2021, 03:08 AM   #6
clinebarger
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Re: TH 400 help

If Governor Pressure is too high for a given speed.....it won't kickdown. If you tune the upshifts right.....Downshift timing will naturally follow suit.
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Old 02-28-2021, 08:30 AM   #7
Getter-Done
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Re: TH 400 help

Quote:
Originally Posted by lux View Post
I have the vacuum modulator hooked up correctly, but I don't know how to test it?
You have to educate me on the governor, I don't know anything about it.
I was under the impression that the kick down solenoid was what down shifted the trans.
Thank you.
There is a kit you can buy in the link below to (dial in) your Governor.
Mainly showing this for (An example) of operation.

Link: https://www.jegs.com/p/B-M/B-M-Trans...51474/10002/-1

This lets you tune your shift points.

If springs and weights are not working freely it will cause issues.







There is also an adjustable modulator you can buy, If you don't have one already,

Link: https://www.jegs.com/i/JEGS/555/6206...6%20Drivetrain

It has a screw in the end where the vaccum hose goes.
That screw is for (fine tuning) the shift points.
Which is not your current issue.
Once the shift issues are fixed this can help fine tune your shift points.






Here is the a link I found on testing the modulator.
So you don't have to read my (Long-winded) version
Link:https://itstillruns.com/test-th400-v...-12179298.html



Hope this helps









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Old 02-28-2021, 11:40 AM   #8
lux
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Re: TH 400 help

Thanks G-Done
I believe all that info will help. I'll start reading and educating myself.
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