I am building a trail truck with a 1998 4.3 6v and a 4l60e tranny. The motor/tranny/pcm were all from a 2wd truck. I added a transfer case after the vss. my question is:
how will the tranny work when I am in 4wd low? will it shift correctly/ at the right time? how can I make it work good? will I have to put a 4wd programm in the PCM?
The factory 4wd trucks used a VSS on the transfer case output side. Not sure that the PCM could differentiate between being in LOW and HIGH (at least not on a 98).
Are you using a divorced transfer case?
I am using a toyota transfere case bolted to the back of the 4l60e. I know it will work, I just dont know how good.
I would think that the 4wd trucks have a input to the PCM telling it your in low range, so it will modify the shift pionts?
Thanks for your input.
Looking at a 98 tune, you are correct. There are different shift tables for 4LOW. Let me look into this some more and see how it knows when you are in 4LOW.
I may run into the same problem but need some application help first. I have a2007 LC9 (5.3) with 2006 4l60E going in front of a 1985 vintage NP208 transfer case.
I was looking at a Jagsthatrun VSS that plugs into the tranfer case speedo output.
Does anyone know which type VSS I will need to work with the LC9 ECM? 4 pulse, 2 pulse or something else? If the OP's question is answered it will also help me figure out if my setup would work when in low range. There is no feedback to the ecm from the old dumb transfer case to let the computer know that the gear ratio just changed to 2:1
You are talking about a completely different PCM and engine. Would be best to start another thread to avoid confusion.Originally Posted by markeheiden
I may run into the same problem but need some application help first. I have a2007 LC9 (5.3) with 2006 4l60E going in front of a 1985 vintage NP208 transfer case.
I was looking at a Jagsthatrun VSS that plugs into the tranfer case speedo output.
Does anyone know which type VSS I will need to work with the LC9 ECM? 4 pulse, 2 pulse or something else? If the OP's question is answered it will also help me figure out if my setup would work when in low range. There is no feedback to the ecm from the old dumb transfer case to let the computer know that the gear ratio just changed to 2:1
Looking at this schematic from a 98 4x4, there is a switch on the transfer case that supplies ground to connector C4 pin 23 at the PCM. This will signal the PCM to switch to the 4LOW tables.
O.K. I have the motor conversion working as a 2wd truck right now. I havent tried 4 low yet, becouse I am having a problem with the VSS sencor.
The VSS is putting out a good signal (as I accellerate the AC voltage does up)put the PCM is seeing a bouncing signal! My scanner is showing that the speed is bouncing from about 20 MPH to 60 MPH when the truck is going a steady 50 MPH and my voltmeter is showing a steady voltage off of the sencor! What is going on??? any ideas
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