ZF 4HP24 Support

[tomgilmour]

Hi. I'm new to this forum (but have used MS1 Extra for a couple of years). I'd be interested to know if there are any plans to support the ZF 4HP24 box from the Range Rover P38 4.6L ? i think there could be some interest in this in the UK / Europe.

[Bernard Fife]

Tom,

The inputs and outputs are user configurable in the MShift code, so it's certainly plausible that this trans could be run. What needs to happen is someone familiar with the trans to look at the available inputs and outputs in the MShift/GPIO and see how they match up to the transmissions requirements. If some changes are needed to the way things work to support this trans, we may consider doing this, or may leave it to the user to complete the code changes.

Lance.

[nebraska_e28]

Tom do you know if you pinout is same for the 4hp24 & the 4hp22?

[nebraska_e28]

Just bumping an old thread. Has anyone taken this challenge on?

[StevenD57]

Have you read through even part of the 1700+ post thread on the Chrysler 41te transmission?
That thread very effectively demonstrates how much effort is required to support a new transmission.
I too have cars with the ZF 4HP24 transmission in them but I don't know if the amount of documentation
that would be needed to support these transmissions is available or not. Again the 41te thread
shows what sort of documentation and development is needed to support another transmission.
It definitely does not seem like something one person could go off and do in secret by themselves.
The 41te development seems to have taken the efforts of several very smart people including
lots of time from Lance.

[Bernard Fife]

Steven, Nebraska;

Actually it is 120 posts (1700 views) in the Chrysler trans thread. But the point is valid. I don't think it is impossible for one person to do this though, but that person would have to be very knowledgeable on the trans in question, or willing to do quite a lot of digging.

The main information needed to use any trans with MegaShift is:

- How many solenoids control the shifting? (a 4-speed requires at least two, 5 speed to 8 speed trans require at least 3; MShift has 3 standard and one additional optional shift solenoid output circuits).
- Which shift solenoids are on, and which are off in each gear?
- Are any solenoids on only during shifts?
- Are any or all of the shift solenoids pulse width modulated (PWM'd)? If so, at what frequency and duty cycle? Is there a 'refresh' booster cycle on the PWM?
- How many solenoids control the torque converter clutch lock-up (usually one or two)? Are either of these PWM'd? Is the TCC engaged when the solenoid is connected to ground, or to 12V?
- How is the line pressure controlled? If this is done electronically, is line pressure increased or decreased with PWM? Is there a 'dither' cleaning pulse in the PWM?
- what sort of signal does the shift lever send to MShift to tell the trans what gear the driver has selected? Is it 3 or more digital (on/off) switches, or a varying voltage?
- how many teeth are on the wheel for the VSS sensor?

MegaShift can handle any of these, but the user needs to know how to set up the user parameters in the code to match the trans, and the answers to these questions are essential for doing that. A factory service manual will often contain all the info needed (though it may have to be teased out of the troubleshooting info).

Lance.

[Bernard Fife]

I have expanded on the above and put it on a web page, for those that are looking to run 'new' transmission using the MShift controller: http://www.msgpio.com/manuals/mshift/newtrans.html

I will be working on getting the 4L80E and 41te docs completed shortly.

Lance.

[nebraska_e28]

Thank you for the useful information Lance, very much appreciated. If a person had a service manual & could identify which wires control each part of the trans, would it be helpful to log voltages on each to gain some understanding of what each circuit is going under a given rpm & load? From there that data could be used to figure how to properly wire the trans up to MS. Just thinking aloud here.

To the OP, didn't mean to strike a nerve! I intended to bring up a dead subject in case there was anyone out there with some new developments, or even someone that's toyed around with this.

[Bernard Fife]

nebraska_e28,

Logging the voltages can be useful in many cases, but authoritative source material from the service manual is at least as good (mostly because the trans may not be working 100% as designed, there may be errors in the hook-up and the measuring equipment itself, etc.).

But a sharp person with the right equipment and a good plan could figure out the parameters to run their trans using MShift solely by logging the inputs and outputs, as you suggest. RPM and load are most important for the pressure control. For the other I/O, the state of the inputs and outputs in any given gear is most useful (rather than by rpm and load).

One area that sometimes has to be 'scoped is the PWM parameters - both for the shift solenoids (if they use PWM) and for any pressure control devices (like the PC solenoid in the 4L60E). Often this info is missing or incomplete in the manuals, unfortunately.

Lance.

[Peter Florance]

Thank you for the useful information Lance, very much appreciated. If a person had a service manual & could identify which wires control each part of the trans, would it be helpful to log voltages on each to gain some understanding of what each circuit is going under a given rpm & load? From there that data could be used to figure how to properly wire the trans up to MS. Just thinking aloud here.

To the OP, didn't mean to strike a nerve! I intended to bring up a dead subject in case there was anyone out there with some new developments, or even someone that's toyed around with this.

I found some ZF docs that seemed pretty good. I'm trying to talk Todd into it.