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Discussion Starter · #1 ·
Hi all

Looking at keeping my freshly rebuilt 4L80 in my 93 dually for my 6BT swap, the truck was a 6.5 originally and was the last year for a mechanical pump i believe?
What inputs do I need to keep to give the computer so my trans still shifts?
I've read some places it just needs RPM, throttle position and speed sensors?
Or was it all a ruse and I need a controller?

Thanks
 

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4L80e ?

Hi all

Looking at keeping my freshly rebuilt 4L80 in my 93 dually for my 6BT swap, the truck was a 6.5 originally and was the last year for a mechanical pump i believe?
What inputs do I need to keep to give the computer so my trans still shifts?
I've read some places it just needs RPM, throttle position and speed sensors?
Or was it all a ruse and I need a controller?

Thanks
If your truck is DB2 you keep the comp, vssb, tps and cruise control. Its been awhile and I seem to remember that the DB2 equipped trucks the computer was more a trans controller than anything else.

The speed sensor on your 6.5td is at the rear passenger side of the block and cannot be used you will need to pull the speed signal elsewhere like at the vssb.
 

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Discussion Starter · #3 ·
If your truck is DB2 you keep the comp, vssb, tps and cruise control. Its been awhile and I seem to remember that the DB2 equipped trucks the computer was more a trans controller than anything else.

The speed sensor on your 6.5td is at the rear passenger side of the block and cannot be used you will need to pull the speed signal elsewhere like at the vssb.
by speed sensor on the block are you referring to engine speed? isn't RPM taken from a signal from the alternator?
 

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by speed sensor on the block are you referring to engine speed? isn't RPM taken from a signal from the alternator?
Yes, the speed sensor for transmission controller is also the oil pump drive on that 6.5 diesel application.......there is rpm signal "for tachometer" pulled on the OBD 2 diesel applications via the alternator "for the tach" however; I'm not sure that's the case on OBD 1 applications....anyway any gen/alt us used can be interfaced & calibrated for transmission control and you would still have a DRAC/VSSB module to tap into also...you have many options, if its 2wd then 4L80 e would have the speed sensor in the tail section of the trans....if its 4x4 then the speed sensor is attached to the t-case tail section and both go to the DRAC/VSSB module which can be calibrated for tire diameter & gear changes.
 

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Discussion Starter · #5 ·
So can I make the GM TPS work on the Dodge linkage on the Cummins? The sensor seems to need to turn to opposite way than the way the throttle is turned on the Cummins
 

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Discussion Starter · #6 ·
Also you are saying that I need to provide a rpm signal to the vssb module to get the trans to shift?
 

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The older 4L80e transmissions are beasts in of themselves as control goes and I don't remember all the issues however; the guys over at the truck stop dot us have former GM & Dodge techs who can answer your older 4L80e control questions....the newer 4L80s while more complex are easy to control w/aftermarket controllers....older one are IMO APITA.
 
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