swapping from 4HP22 to 4HP22EH ?

[gadget73]

Thought experiment, would it be possible to swap my hydraulic 4HP22 to the electronic 4HP22E at some point if I felt the need to? Some research indicates the EH has a stand-alone trans control unit with apparently some inputs from the ECM. I haven't found much solid info on running one of these in a more or less stand-alone config, and what I have found comes from here

http://www.mye28.com/viewtopic.php?t=91937

If all it needs is a TPS and the same output used for the fuel economy display, I should be able to manage that. The Lincoln has what is called a tripminder, but its a fuel economy display that drives off the injector lift sensor. The car has no TPS, but I should be able to come up with something to install one. Deleting the EGR regulator and mounting a pot in that spot would be simple enough.


Asking because I was offered a 4HP22EH as a parts donor for if/when mine dies and I'm sort of curious if its possible. If its vastly difficult I'll just rebuild the original one if it dies.

[offroadkarter]

I haven't looked into this but a friend of mine was saying a EH could theoretically be controlled by a stand alone controller called a compushift. He was looking into this for a brief window of time.

https://www.hgmelectronics.com/compushi ... t-and-pro/

I would imagine at least one year of 524TD had to run the EH trans but I never knew a lot about the diesels. The EH trans in my 745i had the trans computer built into the DME for the engine, but all the other models had a totally separate trans computer which I'm sure you could get cheap if you wanted to use an OE BMW part.

I can also say after driving an EH trans and two non EH transmissions (one being yours, the other a 733i), the EH is leagues ahead, honestly the shifting is a lot better than your average 4R/AODE.

[gadget73]

Not sure if the diesels got the -EH or not, but US versions ran a different injection pump with electronically controlled timing. There was a computer in the mix to control that, so its possible that also ran the transmission or had an interface to the trans control unit. This one is basically the Euro spec motor with no electronic anything.

I'll have a look at the controller, thanks. Was thinking if there was a way to use OE parts I might be able to do this on the cheap, but I can't find enough details on how these work to know.

If it shifts as good as an AODE it would be an upgrade. The trans in the car is at least as clunky as an AOD, and is arguably worse in some areas. This is all hopefully a long ways off, I really have no desire to drop a pile of money on transmission work just now, especially after having just dealt with the injection pump.

[Nebraska_e28]

You could also build a MegaShift unit for trans control as another option.

[gadget73]

Kinda trying to do this on the cheap-ish if possible. I tend to like OE electronics because they also tend to look like it might be stock and it usually has good reliablity.

I still haven't researched what the output shaft configuration is either. I know the extension housing is specific to the Lincoln, it uses a Ford VSS and slip yoke. I don't know if the output shaft is custom to allow that to work or not. If it is, making the -EH version work might get excessively difficult.