Announcement: 4L60E Billet Reverse Manual Transbrake Valve Body
11-19-2018, 06:19 PM
#1
Announcement: 4L60E Billet Reverse Manual Transbrake Valve Body Design work is partially completed for these. There will likely be some bugs to work out once we begin to cut them on the CNC.
These will be the ultimate fix for 3-4 clutch failure and won't require extreme pressure.
I will post some updates as we make progress on the machining and testing over the next couple of months.
These will be the ultimate fix for 3-4 clutch failure and won't require extreme pressure.
I will post some updates as we make progress on the machining and testing over the next couple of months.
11-20-2018, 07:09 AM
#2
TECH Junkie
I'll be the first to say I'm excited to see this. I had no idea you were working on something like this...especially for the 60e!
11-20-2018, 07:14 AM
#3
TECH Junkie
11-22-2018, 01:04 AM
#4
The circuits are drawn up for this. Clean design with major hydraulic improvements.
We'll be making a 3D CAD drawing over the next couple of weeks then cutting some parts.
As of now,
Internal solenoid design, transbrake functions in first and 2nd gear (1+2 leave), retains OEM boost valve design, retains lockup but only in 4th gear.
Reverse requires transbrake activation.
Obviously reverse pattern.
Retains engine braking.
Overrun clutches are on in reverse and 1-2-3.
We'll be making a 3D CAD drawing over the next couple of weeks then cutting some parts.
As of now,
Internal solenoid design, transbrake functions in first and 2nd gear (1+2 leave), retains OEM boost valve design, retains lockup but only in 4th gear.
Reverse requires transbrake activation.
Obviously reverse pattern.
Retains engine braking.
Overrun clutches are on in reverse and 1-2-3.
11-23-2018, 10:47 AM
#7
The circuits are drawn up for this. Clean design with major hydraulic improvements.
We'll be making a 3D CAD drawing over the next couple of weeks then cutting some parts.
As of now,
Internal solenoid design, transbrake functions in first and 2nd gear (1+2 leave), retains OEM boost valve design, retains lockup but only in 4th gear.
Reverse requires transbrake activation.
Obviously reverse pattern.
Retains engine braking.
Overrun clutches are on in reverse and 1-2-3.
We'll be making a 3D CAD drawing over the next couple of weeks then cutting some parts.
As of now,
Internal solenoid design, transbrake functions in first and 2nd gear (1+2 leave), retains OEM boost valve design, retains lockup but only in 4th gear.
Reverse requires transbrake activation.
Obviously reverse pattern.
Retains engine braking.
Overrun clutches are on in reverse and 1-2-3.
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11-23-2018, 12:31 PM
#8
Easiest fix is to wire brake up to reverse lights.
From a design perspective it adds complexity and this is already a complex setup with overrun circuits, lockup, brake, regulated torque signal, etc.
It also can cause slower transbrake action.
From a design perspective it adds complexity and this is already a complex setup with overrun circuits, lockup, brake, regulated torque signal, etc.
It also can cause slower transbrake action.
12-20-2018, 08:02 AM
#11
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For those of us who do not rebuild transmissions, can you explain what is the exact hydraulic weakness of the 3/4 clutch in a stock 60e, and what is changed in your VB to fix the issue?
12-20-2018, 08:18 AM
#12
TECH Junkie
I don't mean to speak out of turn here...but I'll take a stab at it and jake can come back and correct me later if need be...
The weakness of the 3/4 clutch in the 4l60e is multi faceted.
1. the apply piston is small. It doesn't have the area that one would desire for a high load application (we attempt to remedy this in stock fashion by just increasing pressure...sometimes upwards of 230 psi. the apply force = pressure X area...we can't make the area any larger so we increase the pressure to get more apply force)
2. the clutch area is small. They are very narrow clutches and the total clutch area isn't all that great. You can add more clutches to the stack, but there is always a limit.
3. the fluid circuit is LONG. line pressure has to go through many avenues and through many valves which means there are LOTS of places for circuit leaks. This leads to losses in the system and lower apply pressure actually seen at the clutches.
4. a 3rd gear shift is a synchronous shift. Which means one element has to release at the same time the 3/4 clutches apply. Release the band too quickly or too slowly and you'll have issues...it needs to be just right.
This is unlike a th400 or 4l80e that is all non-synchronous shifts. In those transmissions, one clutch comes on right after the next with no release timing needed during upshifts. This difference between the 60e and 80e adds complexity to shift timing and limits how quickly you can bring the 3/4 clutches on. Since you can only bring them on so fast...that means there is some inherent slip during apply (more than we want) that causes lots of heat and wear.
The weakness of the 3/4 clutch in the 4l60e is multi faceted.
1. the apply piston is small. It doesn't have the area that one would desire for a high load application (we attempt to remedy this in stock fashion by just increasing pressure...sometimes upwards of 230 psi. the apply force = pressure X area...we can't make the area any larger so we increase the pressure to get more apply force)
2. the clutch area is small. They are very narrow clutches and the total clutch area isn't all that great. You can add more clutches to the stack, but there is always a limit.
3. the fluid circuit is LONG. line pressure has to go through many avenues and through many valves which means there are LOTS of places for circuit leaks. This leads to losses in the system and lower apply pressure actually seen at the clutches.
4. a 3rd gear shift is a synchronous shift. Which means one element has to release at the same time the 3/4 clutches apply. Release the band too quickly or too slowly and you'll have issues...it needs to be just right.
This is unlike a th400 or 4l80e that is all non-synchronous shifts. In those transmissions, one clutch comes on right after the next with no release timing needed during upshifts. This difference between the 60e and 80e adds complexity to shift timing and limits how quickly you can bring the 3/4 clutches on. Since you can only bring them on so fast...that means there is some inherent slip during apply (more than we want) that causes lots of heat and wear.
Last edited by MaroonMonsterLS1; 03-08-2019 at 03:19 PM. Reason: simplify
12-20-2018, 08:48 AM
#13
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Kinda what i figured. So what i take is a few of those things can be improved on, a few cannot due to physical limitations. Basically just make the best of a bad (poorly designed) situation.
12-20-2018, 09:58 AM
#14
Is it possible to design it to where the Tbrake isn't needed for reverse? I'm not using a 60e but I'm using a brake that requires brake activation for reverse in my 400, and can't say that I'm a fan of that. Makes me feel like I'm driving a racecar. Just thinking there are more people out there who feel the same, and might make them even more eager to use your product if the transmission doesn't require special trickery to operate. And just to be clear, not in any way downing your product.
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