Re: Loss of diff fluid

From: Kevin Sellstrom (ksellstr@softcom.net)
Date: Tue Mar 25 2003 - 00:03:12 EST


At 04:03 PM 3/24/2003 -0500, you wrote:
>the front axle uses a CAD -
> > central axle disconnect... I was trying to determine if the shafts are
> > totally disengaged from the diff when the truck is in 2wd.
>
>My understanding is that the CAD system was discontinued somewhere around
>'91 - '93 (not sure exactly when).

The disconnects are still used, at least they were through 2002. They only
exist on the solid front axles however.

> Dodge decided that the reliability of
>the CAD system was poor enough that it was better to go with a simpler
>system, even if it puts a bit more wear on the gears.

The reliability of the vacuum motor was generally poor (don't ask how many
have cycled through our various rigs, let alone the lengths of vacuum hose
to be replace every year or two). There are inexpensive after market kits
to replace the vacuum setup with a cable actuated disconnect. There are
occasional issues with the weak link in the splined disconnect section, and
with sealing issues associated with the disconnecting shaft and the shifter
motor.

> Even with that
>system, I believe it only disconnected one side, which means that the
>differential still turns (might be wrong on that last point).

This is correct, they only disconnect the long shaft from the diff. The
carrier still turns and causes some motion in the driveshaft (much less
than full speed however).

>At any rate, I'm pretty sure my '95 doesn't have an axle disconnect, same
>as any of the newer models. The front axle is connected to the wheels
>100% of the time. The only disconnect in 2wd mode is the fact that the
>transfer case is disconnected from the front drive shaft.

Correct, AFAIK, none of the Dana IFS axles use any sort of
disconnect. There isn't really room in the width of the Dak chassis for
one if they wanted to...and it would add more $$$ to the cost of a truck
they're trying to make cheaply. The entire front driveline turns at full
speed all the time, it is only under power however when the transfer case
is engaged. This reflects in the mileage variances between Daks and
vehicles with hubs (with a light throttle foot, our Dak gets the same or
less mileage than my dad's Ram with the larger engine (5.2 vs. 5.9), more
weight, and HUBS).

Kevin

Kevin Sellstrom, W6KTB E-Mail:ksellstr@softcom.net
             ***Wilton, California***

'99 Dodge Dakota CC, 4x4, 5.2,
'69 Dodge D200, 4x2, 318,

Also: '83 Volvo 244Ti, '85 Volvo 244, '68 Volvo 122S, '98 Specialized
Rockhopper A1FS



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