46rh transmission center conversion

[Magnumforce1987]

Hey guys doing a transmission center 46rh transmission pressure switch conversion. Coming across a dilemma got my buddies helping me out with this feature, I’m getting two different answers on how it works…. Does the lock up converter, lock up before the Overdrive or does the overdrive kick in before the lock up? Sorry guys this conversation got me confused.

 

[Professor Fate]

Overdrive first, then lockup.

 

[Magnumforce1987]

Thank you!

 

[TrailBeast]

Hey guys doing a transmission center 46rh transmission pressure switch conversion. Coming across a dilemma got my buddies helping me out with this feature, I’m getting two different answers on how it works…. Does the lock up converter, lock up before the Overdrive or does the overdrive kick in before the lock up? Sorry guys this conversation got me confused.

Yes as said OD, then lockup.

FYI, OD is fed off the third gear pressure, meaning there is no way the trans can apply OD before it’s in third first.

LU can be engaged at any time and any gear.

If you plan on using pressure switches, it’s a good idea to set up OD first, then set up Lockup.
This keeps OD and LU physically separated so it doesn’t cause confusion over which is engaging when.

Set your LU high at first, then lower it to your preference, to keep LU from engaging before OD.

Also keep in mind what happens if you have lower gears, that you pretty much can’t manually downshift to second gear while in overdrive.
The trans will drop out of 3rd and OD at the same time since OD and 3rd use the same feed, and could cause an over rev.

 

[Magnumforce1987]

Yes as said OD, then lockup.

FYI, OD is fed off the third gear pressure, meaning there is no way the trans can apply OD before it’s in third first.

LU can be engaged at any time and any gear.

If you plan on using pressure switches, it’s a good idea to set up OD first, then set up Lockup.
This keeps OD and LU physically separated so it doesn’t cause confusion over which is engaging when.

Set your LU high at first, then lower it to your preference, to keep LU from engaging before OD.

Also keep in mind what happens if you have lower gears, that you pretty much can’t manually downshift to second gear while in overdrive.
The trans will drop out of 3rd and OD at the same time since OD and 3rd use the same feed, and could cause an over rev.

I’m using 44psi for OD and 50psi for LU. runs good, got a vacuum gauge hooked up. I noticed when overdrive kicks in vacuum drops down to 7 inches of vac and OD unit starts to rattle, sounds like bearing noise. At 3rd vacuum is at 16 inches. Never did that when I was using toggle switch to operate OD and LU.

 

[TrailBeast]

I’m using 44psi for OD and 50psi for LU. runs good, got a vacuum gauge hooked up. I notice when overdrive kicks in vacuum drops down to 7 inches of vac and OD unit starts to rattle. At 3rd vacuum is at 16 inches. Never did that when I was using toggle switch to operate OD and LU.

I assume you are using the vacuum switch to get throttle controlled kick down.
It may be that the vacuum switch is the culprit in the OD chatter.
Try bypassing it and see how it acts.
I scraped the vacuum switch on my setup because I found it really wasn’t necessary.
If I need that much acceleration I reach down and turn OD and/or LU off with the switches on my shifter.
The vac switch just added a bunch more junk that really didn’t need to be there.

I have adjustable pressure switches which lets me set the speeds I want, and I plumbed the pressure line from the governor port up to the back of my intake where they are on a bracket on the passenger side of the distributor.
This way I can change the switch settings from under the hood.
Here’s the switches on the shifter and the adjustable switches from NOS in case you are interested.

I’ll be in and out for most of the day, but at very least see any questions you might have this evening.

 

[Magnumforce1987]

I assume you are using the vacuum switch to get throttle controlled kick down.
It may be that the vacuum switch is the culprit in the OD chatter.
Try bypassing it and see how it acts.
I scraped the vacuum switch on my setup because I found it really wasn’t necessary.
If I need that much acceleration I reach down and turn OD and/or LU off with the switches on my shifter.
The vac switch just added a bunch more junk that really didn’t need to be there.

I have adjustable pressure switches which lets me set the speeds I want, and I plumbed the pressure line from the governor port up to the back of my intake where they are on a bracket on the passenger side of the distributor.
This way I can change the switch settings from under the hood.
Here’s the switches on the shifter and the adjustable switches from NOS in case you are interested.

I’ll be in and out for most of the day, but at very least see any questions you might have this evening.

View attachment 1716260537

View attachment 1716260538

Good call, was the vacuum switch. I was able to adjust the switch to a more satisfactory set point. Have a very minimal chatter, definitely not as concerning as before I posted about it. Thank you so much.