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Vss sensor question

1979jimmy350

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I just mounted a 203 behind a 4l60E. Now i am wondering about what to do about the vss sensor, becasue one is needed for the tranny to shift right. Is it possible to install a relctor ring and vss on a 203?
 
I just saw in either Super Chevy Or Hot Rod an adapter that goes right onto the speedo output to send the signal to computers and electric speedos. Damn, cant think of the company. Anybody else see that, i'll see if i can find it.
 
after looking at there site, i was wondering, they are saying that i need to put the vss before the transfer case becasue the reading would be wrong when the tcase is in low range. Is this true, because the stock transfer case has the sensor in the tcase.
 
It needs to go on the tailshaft, so whatever range you are in, it will send the right signal to the putor and not screw up shifting, MPH, etc.
 
b454rat said:
It needs to go on the tailshaft, so whatever range you are in, it will send the right signal to the putor and not screw up shifting, MPH, etc.

my question is then how does it come in the transfer case form the factory? for example if you have a 40 plus per drive shaft revloution, and you have the tcase in low range it wold still output the 40 pluses per rev. Would this not be the same thing as jsut shifting gears in the tranny?
 
How that parts works, I don't know. I think what they mean by that is it reads 40 PPM. I think, I dunno.
 
4x4 computer has a trigger wire for 4x4 use. then the computer know what ratio it is in.

40ppm = 40 pulses per rotation of the tone ring.
 
4l60es are a pretty complicated trans. they require input from CTS,MAP/MAF,TPS, brake switch and someothers i prolly dont rember to shift right. gotts have them all in synk to shift right.
If you have the ECM and all th other stuff and just need the VSS I think Advance Adapters makes a Vss kit that may work for you. Might need to call them and see
 
Output shaft RPM is the same for a given MPH. The engine turns faster in 4lo than it does in 4hi (twice as fast in a 205 for instance) but all that is done before the speedometer cable/VSS, just like the transmission shifting. It needs to be on the transfercase output shaft.

JTR is a good company, but they are a little off on some of the 4wd truck stuff.
 
dyeager535 said:
Output shaft RPM is the same for a given MPH. The engine turns faster in 4lo than it does in 4hi (twice as fast in a 205 for instance) but all that is done before the speedometer cable/VSS, just like the transmission shifting. It needs to be on the transfercase output shaft.

JTR is a good company, but they are a little off on some of the 4wd truck stuff.

thats exactly what i was thinking. and after looking at the ecm pinouts there is a wire that tells the PCM when the transfer case is in low range. I hoppfuly will have this project running soon so i can start on trying to run TPI with a 4l60E using a 93-94 Truck PCM
 
I had heard that some applications later on cut ABS when in low range, but it is entirely possible that at some point GM put a transmission/t-case "variable" in the ECM, so that instead of having a separate output VSS on the t-case, everything was done from the transmission, so less parts between 2wd and 4wd.
 
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