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8HP70 automatic transmission
turbodisplay - 7/2/15 at 06:32 PM

Finally bought a bmw 8HP70 automatic gearbox in 4x4 guise.
Next bit of fun will be changing the electronics inside for one of my own creation.
So question is is their anyone who knows which solenoids contols what?
I will post a picture of the controller once I have reduced the resoloution.
There are 9 solenoids in total.
One controls the Park, identified as the green solenoid on its own.
Leaving 3 orange, 1 black and 4 white solenoids.
5 solenoids control the brakes and cluches, an educated guess is the 3 orange correspond to 2nd gear.
So 2 other solenoids are for gear selection.

Leaving 3 which must be for the torque converter lockup (one or two) and pressure regulation(one or two).
Also noticed there is a PZT marking with a M10*1mm thread, blanked off. Gues that is a pressure takeoff for a sensor connection.

Another question is does anyone know what amount of teeth are on the input and output shafts for the speed sensor?


Failing anyone in the know responding, it will have to be good trial and error!

Thanks in advance.

Darren

Ps for the people why I want an automatic transmission, I have been drawn in by the speed of gear change, do love a manual, but thinking on the track 200ms changes will be fun, plus the ratios are close. On the road the high gearing will help fuel economy (0.66 for 8th gear). The SLR used a torque convertor auto to good effect.


turbodisplay - 8/2/15 at 08:15 AM

8hp70
8hp70


rusty nuts - 8/2/15 at 08:41 AM

Can't help with any info on the box except a few years ago our local auto box specialist was having problems getting any info on Renault slush boxes until he was on holiday in the states and managed to get everything he needed under their freedom of information regulations. Best of luck


turbodisplay - 8/2/15 at 09:23 AM

Thanks that is a useful thing to know!
Jeep use their transmission so is another avenue for info.
All else fails I will be in the states for a wedding later this year.


Thanks
Darren


Angel Acevedo - 9/2/15 at 08:06 PM

I live in México and may have similar perks as in the US.
Besides I will be confined to a bed most of the time for almost two weeks.
So plenty of time to navigate te net provided me you give me pointers at what to look for as a quick google brought a lot of info but hard to read as I'm on my phone now.
Laptop will be available later today and will be my best frien for a while.
Regards
AA


turbodisplay - 9/2/15 at 09:03 PM

Thanks for that, had a very serious look on the net, managed to find the order of the solenoids for which gears, but not specifically what solenoid does what. So I think that someone who deals with these transmissions will be most likely source.

Being fairly a new transmission causes problems.

I`m designing the controller now, so will hopefully have it made in a month. Will have a look at transmission specialists to see if they can help.
I will be able to do the good old trial an error as a last resort.

Thanks
Darren