4R70W tcc lock up in 1st gear

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ol boy
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4R70W tcc lock up in 1st gear

Post by ol boy »

Doing some reading on the 4r70 shows that torque converter lock up is hydraulic disabled when the transmission is in 1st gear.

http://www.sonnax.com/articles/194-ford ... h-circuits

This shows the 2 types of tcc lockup ideas and how they are implemented. My question is... what internal tranny mods could be done to get tcc lockup in first gear? All I can think of is a plunger and spring that get applied or released when in 1st gear to block pressure to the bypass valve.

Thanks Ryan

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306 SBFord, Torquer II EFI intake, 60 lbs injectors, 8 LS2 coils, VS Racing 7668 turbo, 4R70W, MS3x fw1.4 w/built in trans controller.
ol boy
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Re: 4R70W tcc lock up in 1st gear

Post by ol boy »

Update on this... found some hydraulic schematics and when in 1st gear a plunger is applied which dumps any tcc pressure back into the pan. Looks to be as simple as plugging a check ball port and you can have tcc lock up in first.

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306 SBFord, Torquer II EFI intake, 60 lbs injectors, 8 LS2 coils, VS Racing 7668 turbo, 4R70W, MS3x fw1.4 w/built in trans controller.
BlueScreen
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Re: 4R70W tcc lock up in 1st gear

Post by BlueScreen »

Hi,

Have you figured out how to do it ? I too want to use the lockup in 1st gear on my 4R75W and I can't find any info on how to do it anywhere.

Full disclaimer: I do not use Megasquirt, I have a Quick4 Controller that allows me to use the lockup in 1st gear.

Thanks !
1997 Mustang GT, TFS heads, built teksid, KB 2.6H @ 18psi, and some bacon
1.383 / 6.497 / 10.18 @ 132.68 mph
MS3Pro PnP 1.5.2
ol boy
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Re: 4R70W tcc lock up in 1st gear

Post by ol boy »

If you Google the hydraulic circuits you'll find there is a check valve and plunger that exhaust the tcc pressure when 1st gear is commanded. Should be as simple as plugging the check valve.

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306 SBFord, Torquer II EFI intake, 60 lbs injectors, 8 LS2 coils, VS Racing 7668 turbo, 4R70W, MS3x fw1.4 w/built in trans controller.
BlueScreen
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Re: 4R70W tcc lock up in 1st gear

Post by BlueScreen »

But did you get it to work ? If so, what exactly did you do ?

I found some hydraulic schemas, and determined what checkball I would need to plug. I opened the valve body this week-end, and the checkball is already blocked by a stiffener plate. I'm trying to find more documentation, and found this => http://www.google.com/patents/US5445016
If I understand correctly, there's nothing we can do to apply TCC in 1st gear.

Thanks
1997 Mustang GT, TFS heads, built teksid, KB 2.6H @ 18psi, and some bacon
1.383 / 6.497 / 10.18 @ 132.68 mph
MS3Pro PnP 1.5.2
ol boy
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Re: 4R70W tcc lock up in 1st gear

Post by ol boy »

Looks to me that plugging B7 check ball orfice will keep the tcc fluid from dumping into the pan when the 2-3 shift valve not active.

I have not tried this yet. This trans is in my daily driver.

One source I have said that you'll need to apply higher pressure to the bypass clutch control valve to get good lock up in first.

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306 SBFord, Torquer II EFI intake, 60 lbs injectors, 8 LS2 coils, VS Racing 7668 turbo, 4R70W, MS3x fw1.4 w/built in trans controller.
BigBlockMopar
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Re: 4R70W tcc lock up in 1st gear

Post by BigBlockMopar »

What's the reason you'd want to have lockup in those 2-3 seconds you're in that gear during acceleration?
Daily driver: 1973 Dodge Dart - 360ci engine - 11.3:1cr - MS3x - ignition only. 42RH/A500 OD+LU transmission / 3.23 gears
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BlueScreen
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Re: 4R70W tcc lock up in 1st gear

Post by BlueScreen »

BigBlockMopar wrote:What's the reason you'd want to have lockup in those 2-3 seconds you're in that gear during acceleration?
It's for drag racing only.
I have a loose torque converter to sling shot the car off the line. The downside is I hit the rev limiter at 30mph because of converter slip and have to shift into 2nd gear. With no slip, I can get 50mph in 1st gear. Accelerating those 20 mph in 1st gear instead of 2nd gear would get me faster time, but for that, I need to stop the slip by engaging the TCC
1997 Mustang GT, TFS heads, built teksid, KB 2.6H @ 18psi, and some bacon
1.383 / 6.497 / 10.18 @ 132.68 mph
MS3Pro PnP 1.5.2
BlueScreen
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Posts: 24
Joined: Thu Jan 19, 2017 10:48 am
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Re: 4R70W tcc lock up in 1st gear

Post by BlueScreen »

ol boy wrote:Looks to me that plugging B7 check ball orfice will keep the tcc fluid from dumping into the pan when the 2-3 shift valve not active.

I have not tried this yet. This trans is in my daily driver.

One source I have said that you'll need to apply higher pressure to the bypass clutch control valve to get good lock up in first.

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I was pretty sure about plugging the B7 ball, but having the VB in my hands, I realized this ball doesn't do anything in my VB. It only communicate with B8, but both are in the same pocket and moving them doesn't do anything.

The Google Patent link I posted up here says that even if the TCC selenoid is energized, it would not do anything because it doesn't receive oil pressure from the 1-2 shift valve. I would need to manually move the bypass clutch control valve when I want the lockup, but there's no way I can do that.

I can't find anyone that succeeded to make this work, this might mean something...
1997 Mustang GT, TFS heads, built teksid, KB 2.6H @ 18psi, and some bacon
1.383 / 6.497 / 10.18 @ 132.68 mph
MS3Pro PnP 1.5.2
ol boy
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Posts: 1532
Joined: Mon Sep 10, 2007 3:06 am
Location: Tucson, Az

Re: 4R70W tcc lock up in 1st gear

Post by ol boy »

It looks like I miss spoke on the 2-3 shift valve. It's still attached to the 1-2 shift valve, but the 1-2 side dumps any pressure that would fill from the tcc solenoid while in first. The tcc solenoid gets its pressure from the solenoid pressure reg valve which is supplied by the line pressure from the epc solenoid. B8 looks to be checking until a shift into 2nd has happend. B7 also checks once in 2nd but passes fluid in first if pressure comes from the tcc.

https://postimg.cc/image/p4xx9wsit/

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306 SBFord, Torquer II EFI intake, 60 lbs injectors, 8 LS2 coils, VS Racing 7668 turbo, 4R70W, MS3x fw1.4 w/built in trans controller.
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