Jump to content
Volvospeed Forums

How Do You Shift Automatic Transmission?


FAST850R

Recommended Posts

So ive read this before

http://forums.turbobricks.com/showthread.php?t=47229&highlight=poi+paddle+shifted+960

The whole paddle shifters thing is genius- I wish i understood half of what hes talking about... its strange.. I understand the programming but not the application of half of it..

How exactly do these transmissions work? It is just a simple voltage signal being thrown at the tranny (Where are those wires?) to tell it to shift into a gear... if we could determine what voltage is equal to what gear then couldnt we just splice into those wires and send the voltage down them that we want to shift to the corresponding gear?

It seems like such a simple concept... is there any blue print/ information on how exactly these trannys work that i could read?

Since the trans has it's own ECU, I always wondered if a tuner could make a chip/tune for the trans to alter the shift points or engagement.

Link to comment
Share on other sites

  • Replies 62
  • Created
  • Last Reply

Since the trans has it's own ECU, I always wondered if a tuner could make a chip/tune for the trans to alter the shift points or engagement.

Yeah, such a thing exists, it replaces the TCU, and moves it be just aft of the center console in the cabin, directly interfaced with the driver's intents. :lol:

Link to comment
Share on other sites

Yeah, such a thing exists, it replaces the TCU, and moves it be just aft of the center console in the cabin, directly interfaced with the driver's intents. :lol:

I see what you did there... :lol: :lol: :lol:

For a daily driven station wagon, I really have zero interest in a manual gearbox. If I cared about it more, I'd drop the auto and modify the valve bodies or accumulators, but it's good enough for me as-is.

Link to comment
Share on other sites

The way I thought about going about it was to trick the TCU into thinking that the car was always at 0mph. From there you can emulate "L" for first, Winter + "3" for 2nd, Winter + "D" for 3rd, and then 4th would be "D" and the real speed.

something like that anyway.

Link to comment
Share on other sites

His micro controller just satisfies the Tranny ECU.

Basically the micro controller operates the logic circuit for each gear.

Essentailly each gear is engaged by the solenoids changing fluid pressure.

Each solenoid is turned on and off at proper times for specific gear.

This is why the logic controller is essentail.

So when you shit into a gear you have proper sync of shutting off the last gear configuration.

I don't recall where I found this information,

you'd have to save it at the website not here.

http://yfrog.com/5jautotransdiagnosisd

850

VALVE BODY SOLENOIDS

Valve body solenoids, mounted on the valve body, are output

devices controlled by signals received from the TCM. The No. 1 and No.

2 solenoids are used to control transaxle shifting. No. 3 solenoid is

used to control torque converter lock-up. No. 4 solenoid is used to

control transaxle line pressure. For solenoid locations, See Fig. 2.

For valve body solenoid usage, see VALVE BODY SOLENOID APPLICATION

VALVE BODY SOLENOID APPLICATION (1)

Shift Lever Position No. 1 Solenoid No. 2 Solenoid

"D" (Drive)

1st Gear ............... OFF ...................... ON

2nd Gear ............... ON ....................... ON

3rd Gear ............... ON ...................... OFF

4th Gear ............... OFF ..................... OFF

Seems complicated to get something right.

But if i had some time and the $ tree was a bit higher I'd be in favor for the push buttons on the wheel.

Link to comment
Share on other sites

this thread makes me :D

lol hard...

can you please make a video of your neutral bombs? (until it finaly dies)

its would be an awesome way to make your tranny go out before your swap...

Link to comment
Share on other sites

850

VALVE BODY SOLENOIDS

Valve body solenoids, mounted on the valve body, are output

devices controlled by signals received from the TCM. The No. 1 and No.

2 solenoids are used to control transaxle shifting. No. 3 solenoid is

used to control torque converter lock-up. No. 4 solenoid is used to

control transaxle line pressure. For solenoid locations, See Fig. 2.

For valve body solenoid usage, see VALVE BODY SOLENOID APPLICATION

VALVE BODY SOLENOID APPLICATION (1)

Shift Lever Position No. 1 Solenoid No. 2 Solenoid

"D" (Drive)

1st Gear ............... OFF ...................... ON

2nd Gear ............... ON ....................... ON

3rd Gear ............... ON ...................... OFF

4th Gear ............... OFF ..................... OFF

Seems complicated to get something right.

But if i had some time and the $ tree was a bit higher I'd be in favor for the push buttons on the wheel.

Seems like a simple truth table to me..but of course application is a whole nother story......

Link to comment
Share on other sites

This stupid thread makes it this far, eh?

Seriously, there is ONLY ONE way to shift an auto transmission.

PUT IT IN DRIVE TO GO FORWARD, REVERSE TO GO BACKWARD, PARK TO PARK AND LOW GEAR FOR SLIPPERY WEATHER IF NEED BE!

/thread

Link to comment
Share on other sites

Correct right up to the low gear for slippery weather.

+1

Although if I go WOT under 35-45 mph i'll spin and go into a higher gear before my speed requires it. That's my only reason for using L during a race from a rolling start. From a dig really does not make a diffrence but sometimes will go to second a bit too soon.

I really want a M56 but it will wait until I can afford the swap and a LSD since apparently the stock M56's seem to be hardcore one leggers stock. If they are in that much of a need for LSD's. Do they hook both wheels when going straight? My auto even though the torque split may not be equal the lines it leaves are :)

Link to comment
Share on other sites

AND LOW GEAR FOR SLIPPERY WEATHER IF NEED BE!

/thread

Wow...someone needs to go back to driver's ed! :lol:

Auto trans operation FAIL!

Link to comment
Share on other sites

Wow...someone needs to go back to driver's ed! :lol:

Auto trans operation FAIL!

Get back in your short bus, captain. :lol:

Slippery weather didn't mean OMGWAYTOOMUCHBEWSTNIMMMMSPINNINNNNNN, slippery weather meant, slick roads (fresh snow) where higher RPMs/low gears benefit safety.

You really are a moron.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...