Turbo 400 shift problem

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econo racer
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Turbo 400 shift problem

Post by econo racer » Mon Sep 03, 2018 6:27 am

I have a good turbo 400 stock.Works perfect but shift it in low and run wide open and it shifts buy itself approx 4500 rpm. I need it to go to at least 5500 rpm. I also do not want a manual or reverse shift. Want it to work stock. Any suggestions? :?

In-Tech
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Re: Turbo 400 shift problem

Post by In-Tech » Mon Sep 03, 2018 9:30 pm

Lighten the governor weights. Somebody used to make a kit, B/M comes to mind. It's been a long time since I messed with this stuff, I sort of remember an adjustable modulator would change not only part throttle but full throttle a little too. Hopefully one of the trans pros here will chime in.
Heat is energy, energy is horsepower...but you gotta control the heat.
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6.50camaro
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Re: Turbo 400 shift problem

Post by 6.50camaro » Tue Sep 04, 2018 6:45 pm

No Pro , but have played with the B&M kit a little . The govenour contols shift point even if the lever is left in Low.The trans can be modified with some shift kits to hold in gear no matter what rpm's are. If you go the route of springs and weights start mid way on weights and springs and check. Lighter weight or softer spring raises shift point. The Lightest weights and springs will put you past 6500 rpm's before shift. If you have a line lock you can check shift points doing a burnout. Good Luck . Dan

TRN
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Re: Turbo 400 shift problem

Post by TRN » Thu Sep 13, 2018 1:50 pm

Do you have a WOT switch connected?

GLHS60
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Re: Turbo 400 shift problem

Post by GLHS60 » Sun Sep 30, 2018 4:06 am

This isn't really a problem as stock TH-400's had this feature.

Higher H.P.Engines have a higher "Governor shift" RPM than lower H.P.Engines.

As mentioned, the "Governor Shift" point RPM can be tuned to suit your needs.

I grind some metal off the governor weights to lighten them up to increase the 1-2 shift point.

I like the firm shift to 2nd, with the shifter in low feature, and find it very consistent!!

Thanks
Randy


econo racer wrote:
Mon Sep 03, 2018 6:27 am
I have a good turbo 400 stock.Works perfect but shift it in low and run wide open and it shifts buy itself approx 4500 rpm. I need it to go to at least 5500 rpm. I also do not want a manual or reverse shift. Want it to work stock. Any suggestions? :?
Sherwood Park
Alberta,Canada

vds
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Re: Turbo 400 shift problem

Post by vds » Tue Oct 16, 2018 12:18 am

You will need to modify the 1-2 shift valve to stop it upshifting in to 2nd, with manual 1st selected
Hydramatic designed it this way I wouldn't suggest attacking the govener

geraldtson
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Re: Turbo 400 shift problem

Post by geraldtson » Tue Oct 16, 2018 10:01 pm

vds wrote:
Tue Oct 16, 2018 12:18 am
You will need to modify the 1-2 shift valve to stop it upshifting in to 2nd, with manual 1st selected
Hydramatic designed it this way I wouldn't suggest attacking the govener
I agree. Go to crankshaft coalition turbo 400 rebuild tech,scroll about halfway down page till you see valve body.
"You must remove 1-2 shift valve and grind to flats on the land designated by arrow and plug exhaust hole in the valve body also designated by arrow".
That's all.

vds
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Re: Turbo 400 shift problem

Post by vds » Thu Oct 18, 2018 4:46 am

Spot on geraldtson. From memory there are two different sized 1-2 shift valves used in the TH400. The shift kit
people used to sometimes supply the two different valves, depending on which shiftkit you had been delivered,
but you can achieve the same with the original valve, and you do need to block that hole in the valvebody
casting. Unfortunately they are not as plentiful as they once were, they are a great transmission, and no solenoids,
except for the kickdown !

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af2
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Re: Turbo 400 shift problem

Post by af2 » Sun Oct 21, 2018 6:19 pm

And back to the gov????????? I have 2 cars out there that leave in drive and the trans shifts at 7200 every time using the gov. There are more ways to make things work. Yes they are 400 with no band and are dead consistent at 10.90.
GURU is only a name.
Adam

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