The gears don't affect your speedo. The only thing that will affect your
speedo is if you change the diameter of your rear wheels and can't/don't set
the correct entry in the PCM table for the size wheel you have.
Ron
00 PB SLT QC 4X2 5.9 46RE 3.92 LSD
For modifications see my DML Profile (URL follows)
http://www.twistedbits.net/WWWProfile/dakota/Kw9pV1EkFeOYY
-----Original Message-----
From: owner-dakota-truck@dakota-truck.net
[mailto:owner-dakota-truck@dakota-truck.net]On Behalf Of Tim Althoff
Sent: Wednesday, June 12, 2002 7:24 PM
To: dakota-truck@dakota-truck.net
Subject: RE: DML: 3.91 gears ???
ok so all this talk has me all messed up! does it make your Speedo fast or
slower? simple answers...
Tim Althoff
99 V6 RC 5-speed SY
http://www.yllwdkta.com
http://go.to/ohiomeet
-----Original Message-----
From: owner-dakota-truck@dakota-truck.net
[mailto:owner-dakota-truck@dakota-truck.net]On Behalf Of Ronald Wong
Sent: Wednesday, June 12, 2002 10:09 PM
To: dakota-truck@dakota-truck.net
Subject: RE: DML: 3.91 gears ???
You're mistaken. The RWSS (rear wheel speed sensor) sends the signal to the
CABS (computer anti-lock brake system) which gets the tire size entry from
the PCM for the speedo calculation. If everything you said was true, then
you would be right, however, the rwss sits between the differential and the
rear wheels. That means the rwss picks up the rotation of the wheels but
has no idea of the difference between the ring and pinion gear. You're also
limited in the size of wheel you choose for your Dak. The table in the PCM
contains approx. five entries. Those are the wheel size it came with plus
four other pretty much standard size wheels (tires and rims combined). If
you get a size that is out of the ordinary your speedo will be off if you
get to the nearest setting to the correct one. Before anyone asks, the
changing of the entry that your PCM will pick requires a flash to the PCM
from the dealer. Depending on how well you know your dealer, or vice versa,
that flash can cost up to $75 USD.
Ron
00 PB SLT QC 4X2 5.9 46RE 3.92 LSD
For modifications see my DML Profile (URL follows)
http://www.twistedbits.net/WWWProfile/dakota/Kw9pV1EkFeOYY
-----Original Message-----
From: owner-dakota-truck@dakota-truck.net
[mailto:owner-dakota-truck@dakota-truck.net]On Behalf Of Jon N. Benignus
Sent: Wednesday, June 12, 2002 6:49 PM
To: dakota-truck@dakota-truck.net;
dakota-truck-moderator@bent.twistedbits.net
Subject: Re: DML: 3.91 gears ???
> Only a tire
> size change will affect your speedometer.
I don't think so.
A taller tire is in effect raising the gear ratio, therefore the axles and
driveshaft turn slower. Going to a taller gear does the same thing.
The sensor measures pulses on the axle or driveshaft depending on the speed
they turn, right? Lower gear, axles, driveshaft and engine spin faster gor a
given speed, therefore more pulses, higher speedo reading.
Correct me if I'm mistaken.
Jon
STL MO
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