TH-400 guys please come on (LSX 441ci &TH-400 ) Info
08-25-2013, 01:41 AM
#1
On The Tree
Thread Starter
TH-400 guys please come on (LSX 441ci &TH-400 ) Info Hi everyone
Iam currently working on my build (f2 charged 441lsx) and i felt it was time to get an auto tranny. My tranny is currently being built at Jakes performance. I have a few questions since this is my first time iam going to own a built 400 tranny. The transmission is going to be fully built and it will have a manual reverse pattern valve body with a ratchet shifter. Also it will have the neutral after 3rd soo the pattern will be P R 1 2 3 N.
-if its possible can some guys who owns a similiar setup pic their interior i would like to see how the shifter should be mounted and how it looks.
-and when dynoing it after the run i put it into neutral or just let of the gas and then when rpms come down go to 2nd then 1st.
-also i was told i can use R as neutral also by engaging the trans brake, but to do that the car has to be at rest? Or can while driving in 1st or 2nd put it into R with trans brake?
Sorry guys if some questions are stupid and answer is obvious i just want to make sure i dont miss out anything. Any tips and help is greatly appreciated
Thanks
Iam currently working on my build (f2 charged 441lsx) and i felt it was time to get an auto tranny. My tranny is currently being built at Jakes performance. I have a few questions since this is my first time iam going to own a built 400 tranny. The transmission is going to be fully built and it will have a manual reverse pattern valve body with a ratchet shifter. Also it will have the neutral after 3rd soo the pattern will be P R 1 2 3 N.
-if its possible can some guys who owns a similiar setup pic their interior i would like to see how the shifter should be mounted and how it looks.
-and when dynoing it after the run i put it into neutral or just let of the gas and then when rpms come down go to 2nd then 1st.
-also i was told i can use R as neutral also by engaging the trans brake, but to do that the car has to be at rest? Or can while driving in 1st or 2nd put it into R with trans brake?
Sorry guys if some questions are stupid and answer is obvious i just want to make sure i dont miss out anything. Any tips and help is greatly appreciated
Thanks
08-26-2013, 06:06 PM
#2
1. Alot of people reuse the 6 speed console to put the shifter through. There are tons of pics of this if you search.
2. Do not throw the trans in nuetral after a WOT 3rd gear run. Just take a look at the last tip on the page of one of the most respected auto builders in the united states:
http://www.rosslertrans.com/Burn-Out...rocedures.html
3. I've never personally heard this, but I know I would never want to touch the transbrake PERIOD while my car was moving.
Just curious, why did you change the valve body to put nuetral at the very bottom, that would seem very strange to drive/stage at the track.
2. Do not throw the trans in nuetral after a WOT 3rd gear run. Just take a look at the last tip on the page of one of the most respected auto builders in the united states:
http://www.rosslertrans.com/Burn-Out...rocedures.html
3. I've never personally heard this, but I know I would never want to touch the transbrake PERIOD while my car was moving.
Just curious, why did you change the valve body to put nuetral at the very bottom, that would seem very strange to drive/stage at the track.
08-26-2013, 10:50 PM
#3
First,
The link to the Rossler site is a good piece of information.
You NEVER want to neutral a transmission at the end of a run or at high speed unless it is specifically built to do so. Then if it is, and you do so, you MUST keep the engine running. It should also be apparent you also wouldn't want to shut off the engine while at high speed.
The really short reason is that the gearset that provides gear reduction/multiplication of torque in 1st/2nd gear, becomes an overdriving gearset when the transmission is placed into neutral or the pump quits making pressure (engine killed). The direct drum in a TH400, TH350, 4L80E, C4, C6, 727, 904, or almost any other automatic becomes a cast iron grenade with potentially over 20,000 rpm. This WILL go through the case and sometimes even through the SFI rated shields/blankets.
Basically, input shaft should remain the input. When you cut it loose from the planets, the output shaft becomes the driver and the transmission becomes a BOMB.
We build some units with a "safe neutral". This can be a forward pattern where neutral keeps the direct clutches engaged (in the case of some of our 4L80Es), or it can be a reverse pattern.
Most pro transbrakes require engaging the transbrake to activate reverse. On many TH400's this can be done in the Reverse or Neutral position. Both are the same hydraulically.
One some VB designs we use, the pattern is P-R/N-1-2-3-N.
Stock is P-R-N-D-2-1, 6 detents.
Since you don't need two detents next to each other that do the exact same thing, as in the case of many transbrakes where there is no effective reverse position and the transbrake must be engaged to back up, you can move neutral to a convenient spot on the pattern.
The safe neutral VB we use has the above pattern. If you shift from Park to R/N, you then engage the button to backup. Or wire it in to a switch or reverse lights.
Then you can shift from the R/N position to 1st.
We also use an aluminum direct drum when using this type of valve body, so that not only does the valve body design prevent the trans from exploding but we add a margin of safety in with the drum as well.
The link to the Rossler site is a good piece of information.
You NEVER want to neutral a transmission at the end of a run or at high speed unless it is specifically built to do so. Then if it is, and you do so, you MUST keep the engine running. It should also be apparent you also wouldn't want to shut off the engine while at high speed.
The really short reason is that the gearset that provides gear reduction/multiplication of torque in 1st/2nd gear, becomes an overdriving gearset when the transmission is placed into neutral or the pump quits making pressure (engine killed). The direct drum in a TH400, TH350, 4L80E, C4, C6, 727, 904, or almost any other automatic becomes a cast iron grenade with potentially over 20,000 rpm. This WILL go through the case and sometimes even through the SFI rated shields/blankets.
Basically, input shaft should remain the input. When you cut it loose from the planets, the output shaft becomes the driver and the transmission becomes a BOMB.
We build some units with a "safe neutral". This can be a forward pattern where neutral keeps the direct clutches engaged (in the case of some of our 4L80Es), or it can be a reverse pattern.
Most pro transbrakes require engaging the transbrake to activate reverse. On many TH400's this can be done in the Reverse or Neutral position. Both are the same hydraulically.
One some VB designs we use, the pattern is P-R/N-1-2-3-N.
Stock is P-R-N-D-2-1, 6 detents.
Since you don't need two detents next to each other that do the exact same thing, as in the case of many transbrakes where there is no effective reverse position and the transbrake must be engaged to back up, you can move neutral to a convenient spot on the pattern.
The safe neutral VB we use has the above pattern. If you shift from Park to R/N, you then engage the button to backup. Or wire it in to a switch or reverse lights.
Then you can shift from the R/N position to 1st.
We also use an aluminum direct drum when using this type of valve body, so that not only does the valve body design prevent the trans from exploding but we add a margin of safety in with the drum as well.
