4L70e/LS swap questions
03-04-2014, 02:01 PM
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4L70e/LS swap questions I have searched and searched for some answers on this just not sure what i've got my self into here... Maybe this thread belongs in the conversions forum, but here it goes.
background: I have a 1969 Nova and i'm and swaping in an LY6 and 4l70e. I'm going to run the Holley dominator stand alone ecu/pcm.
Now for my questions:
1) why can't I find a shifter made SPECIFICALLY for the 4L60 65 70e trans (yea I know that almost any '4spd' GM shifter can be made to work) I'd prefer to just bolt it in and not have to dick with making sure park is park 1st is 1st ect...
2) I've read that a ratchet shifter doesn't gain you anything in the electronic transmissions other than feel. Is this true? Why? 1st gear is still first gear even if there is a sensor in the back of the trans right?
3) With a stand alone, can these transmission be programmed? I'd love to be able to shift 1st 2nd and 3rd manually but if i'm not in the mood for shifting toss it into 'OD' 4th and let that be a fully automatic tansmission, so it shifts all gears automatically?
Please forgive me if these are juevenille questions - this will be my first 'fun' automatic transmission
background: I have a 1969 Nova and i'm and swaping in an LY6 and 4l70e. I'm going to run the Holley dominator stand alone ecu/pcm.
Now for my questions:
1) why can't I find a shifter made SPECIFICALLY for the 4L60 65 70e trans (yea I know that almost any '4spd' GM shifter can be made to work) I'd prefer to just bolt it in and not have to dick with making sure park is park 1st is 1st ect...
2) I've read that a ratchet shifter doesn't gain you anything in the electronic transmissions other than feel. Is this true? Why? 1st gear is still first gear even if there is a sensor in the back of the trans right?
3) With a stand alone, can these transmission be programmed? I'd love to be able to shift 1st 2nd and 3rd manually but if i'm not in the mood for shifting toss it into 'OD' 4th and let that be a fully automatic tansmission, so it shifts all gears automatically?
Please forgive me if these are juevenille questions - this will be my first 'fun' automatic transmission
03-04-2014, 02:39 PM
#2
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I have a B&M Megashifter which will properly shift a 4L60E or 4L70E.
You are correct that a rachet shifter has little value...
When you move the shifter from e.g. [D2] to [D3] the trans will NOT necessarily shift from 2nd to 3rd gear, instead you have only given the PCM permission to shift to 3rd gear WHEN and IF it decides. The tune determines the conditions under which it shifts or doesn't shift.
Since the shifting is completely controlled by the PCM, it is possible to replace it with a dedicated trans controller which will allow manual shifting without or without paddle shifters.
BTW - What year is your 4L70E and what year PCM are you using to control it? Did the engine, trans and PCM come from a donor car or a crate kit? The reason I ask is that some newer 4L70E will not work with older PCMs.
You are correct that a rachet shifter has little value...
When you move the shifter from e.g. [D2] to [D3] the trans will NOT necessarily shift from 2nd to 3rd gear, instead you have only given the PCM permission to shift to 3rd gear WHEN and IF it decides. The tune determines the conditions under which it shifts or doesn't shift.
Since the shifting is completely controlled by the PCM, it is possible to replace it with a dedicated trans controller which will allow manual shifting without or without paddle shifters.
BTW - What year is your 4L70E and what year PCM are you using to control it? Did the engine, trans and PCM come from a donor car or a crate kit? The reason I ask is that some newer 4L70E will not work with older PCMs.
03-04-2014, 03:12 PM
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I have a B&M Megashifter which will properly shift a 4L60E or 4L70E.
You are correct that a rachet shifter has little value...
When you move the shifter from e.g. [D2] to [D3] the trans will NOT necessarily shift from 2nd to 3rd gear, instead you have only given the PCM permission to shift to 3rd gear WHEN and IF it decides. The tune determines the conditions under which it shifts or doesn't shift.
Since the shifting is completely controlled by the PCM, it is possible to replace it with a dedicated trans controller which will allow manual shifting without or without paddle shifters.
BTW - What year is your 4L70E and what year PCM are you using to control it? Did the engine, trans and PCM come from a donor car or a crate kit? The reason I ask is that some newer 4L70E will not work with older PCMs.
You are correct that a rachet shifter has little value...
When you move the shifter from e.g. [D2] to [D3] the trans will NOT necessarily shift from 2nd to 3rd gear, instead you have only given the PCM permission to shift to 3rd gear WHEN and IF it decides. The tune determines the conditions under which it shifts or doesn't shift.
Since the shifting is completely controlled by the PCM, it is possible to replace it with a dedicated trans controller which will allow manual shifting without or without paddle shifters.
BTW - What year is your 4L70E and what year PCM are you using to control it? Did the engine, trans and PCM come from a donor car or a crate kit? The reason I ask is that some newer 4L70E will not work with older PCMs.
The trans is from a Trail Blazer SS i'm uncertain of the year - but I think 07.
I won't have a 'factory' PCM the Holley dominator takes care of all the electrical bits from the engine and trans.
*so when looking for a shifting mechanism should I be looking at a 700R4 shifter?
03-05-2014, 11:46 AM
#4
Moderator
An '07 trans should work with older PCMs or common Trans controllers.
The B&M shifter instructions imply that most GM transmissions have the same detent positions, certainly the 700R4 and 4L60E are the same.
I have the B&M Transmission Lever #20462 (picture below) which attaches to the shift shaft on the trans. It has instructions on how to hook it up to the Megashifter and is marked for F(orward) and B(ack) for installation. It has three holes, one for Megashifter, one for Unimatic and one undocumented. Strangely the Megashifter position did not work for me; I ended up flipping the lever front/back and connecting to the undocumented hole (rightmost in picture). All the detents then aligned perfectly from Park to D1.
The B&M shifter instructions imply that most GM transmissions have the same detent positions, certainly the 700R4 and 4L60E are the same.
I have the B&M Transmission Lever #20462 (picture below) which attaches to the shift shaft on the trans. It has instructions on how to hook it up to the Megashifter and is marked for F(orward) and B(ack) for installation. It has three holes, one for Megashifter, one for Unimatic and one undocumented. Strangely the Megashifter position did not work for me; I ended up flipping the lever front/back and connecting to the undocumented hole (rightmost in picture). All the detents then aligned perfectly from Park to D1.
