6hp transbrake tech


Jul 5, 2017
The 6hp and 6R ford transmissions are pretty much the same as far as solenoid shift logic so the same transbrake stuff that the 6r uses could be used on the 6hp, biggest differences are the fact that the 6r uses the pcm for shift control and the 6hp uses a mechatronic unit that communicates to the dme via can.

On the 6R trans brake two OR three relays ( preferably 2) are used to intercept the single from the ecu/tcm to the transmission applying power and inverting the SSB ( shift solenoid B) and SSC, While in 1st gear when the Tbrake button is applied, that causes the forward, Low/reverse and intermediate clutches to be applied thus creating the transbrake function.

So in order for this to work SSB SSC or in the 6hp case EDS2 EDS3 would have to have power applied while in 1st gear, This poses a few problems since the mechatronic unit is internal and attaches directly to the shift solenoid pack on the 6hp so no external wiring or relays are possible.

My idea is to intercept the EDS2 and EDS3 solenoid wiring, run the wiring externally via a bulkhead in the trans pan, case or possibly the X8500 connector since pin 6,7,8 and 9 are not used, that goes to a two relay package that will trigger when a momentary button is pressed.

OK thats the hardware side, as far as the software side Im not sure if the tcu will like all this going on. The ford guys dont have any issues but the mechatronic unit may be a little smarter. Maybe we can make some progress on the tcu and dme xdf to remove any DTC from this


Jul 5, 2017
I'm excited been wanting to do a trans brake setup for awhile. Keep us posted
It should help on cars with a good tire setup and lsd.

I'll have my e60 pan off or a customers soon and I'll check the viability of it. The biggest what if now is the mechatronic to solenoid wiring. If I can intercept it somehow we'll be golden.
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New Member
Jul 4, 2017
BMW E92 335 6hp21

They are from Poland, and they making stand alone TCU for 6hp and 8hp transmissions. With that you have tbrake, auto, or even manual with 'clutch'. You can release power from torque converter when wanted.


Everything is in polish, but if you want more info from them, just ask, a lot of polish people speaking English ;)
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Oct 18, 2016
The 6R80 is the first generation ZF6HP26. That is the same generation as the 6HP19, the predecessor to our 6HP21 which our cars don't have. So while they are similar, the 6R80 is more like the first gen version of our transmissions, IIRC. I'm not sure if Ford made a version from ZF's second generation offering also. I have a 6hp28 sitting at a shop for sale if anyone wants it btw.


Jul 5, 2017
First gen and second gen 6hp/6r use the same shift logic for the solenoids. Zf was pretty good about picking something and sticking with it.