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Proper INTERNAL PRNDL switch alignment pic

Trannyman95

Trannyman95

Transmission Expert
A customer of mine that I have been helping over the past few months on the phone to get his buick fixed, lost 4th gear, called me today saying he was having problems getting it to start. He mentioned having to move the shifter around and the lights on the dash indicating what gear position you were in were randomly lighting up but not in the correct spot. This was causing the car not to start. Right off the bat I knew what had happened as I have an update tech manual describing this exact problem and having a 4T65E apart with the internal type PRNDL switch I can see how easy it would be to do this. Below is a pic of the correct and incorrect way to install the detent spring on the over the internal mode switch. The bulletin states that this will generally NOT store a code in the pcm and that this problem will exist after repair from removing the channel plate inside the trans. Some 99 and up cars with the 4T65E transmission had this switch, Grand Prix through 03 did NOT, they still used the external switch but most other carlines started to use the new internal switch. I just wanted to share this for those brave enough to dig into your own transmissions whatever the reason, gear ratio changes included!

InternalPRNDLswitchpic.jpg
 


Where inside the transmission is this?


Disregard Dave, I didnt remember seeing that in my ATSG books, but I found it. It was in the newer update book I have.
 


Trannyman95 said:
You are safe Scotty, your trans wont have the internal switch
Click to expand...

heyyyy buddy perchance got a pic of the IMS on the 4t80e? the line drawing i have it doesnt look like that unit...
i'm still waiting to find a newer 80e to tear apart and see if it/selector shaft will swap into the older 80e's easily

i think i've worked out how i can rewire the 97-99 80e pressure switch assembly to work like the 65e's logic, without an expensive logic converter....

hook me up buddy :th_thumbsup-wink:
 
Also, if (like me) you accidentally leave the black sensor above or to the right of the channel plate it won't align properly to install into the detent arm.
Don't remove the channel plate to correct this. Instead move the stepped detent plate way around to the right so the internal switch is no longer surrounding the left edge of the stepped plate. Then the left edge of the plastic internal switch piece can be coaxed over the edge of the channel plate. After which you can turn the stepped plate back inside of the internal mode sensor.
HTH, I almost unbolted my channel plate to position this and thought I'd share my time saver.
 
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