88 Ram 250 4Speed OD Auto Swap?

Hi, I was wondering about retro-fitting my 88 Ram 250 with a 4 speed
OD
auto trans?

Did one exist for this chassis that would swap in semi-easily with say
a driveshaft and cross-member swap?

If yes, what model and year etc?

Thanks!

 

Nobody?

 

Its not a terribly difficult swap, but there are a few things to be
aware of. The trans will basically bolt up to any Smallblock Mopar
engine (318/360 in the 80s) if you use the correctly weighted torque
convertor or flexplate. The 360 is externally balanced and has to have a
weight on the convertor, the 318 does not. People put these
transmissions behind big-block v8s in muscle cars, too, but that
requires an adaptor plate and significant modification.

Beyond that, there's the issue of the crossmember that supports the
tail-shaft. The 4-speed is fatter in the tailshaft area (that's where
the O/D was tacked onto the A-904 to create the A-500, or onto the A-727
to create the A-518). You may also have to massage the floorpan to clear
the fatter tailshaft, although with a ram truck it should be minimal. IT
gets pretty extensive for the folks that put these transmissions in
Darts, Valiants, and Barracudas, less-so for B-bodies, not much
difficulty for C-bodies, and virtually no problem for trucks.

And finally, there's control of the lockup convertor and O/D. In the
vehicles that originally came with an A-518 or A-500, the computer would
engage the locking TC and the O/D at the correct times. You CAN control
both with simple toggle switches that you operate manually, but the
danger is that if you improperly engage lockup or leave it engaged upon
coming to a stop, you can overstress and damage the lockup clutch.
Except for the very heavy-duty versions of the 518 that went behind the
Cummins or the V10, the lockup clutch is not meant to handle a great
deal of torque because the computer always disengages it when a lot of
torque is demanded from the engine. There are aftermarket controllers
intended for retrofitting these transmissions to muscle-cars that work
it all automatically based on throttle position and manifold vacuum, so
it would be best to consider that option.

 

Its not a terribly difficult swap, but there are a few things to be
aware of. The trans will basically bolt up to any Smallblock Mopar
engine (318/360 in the 80s) if you use the correctly weighted torque
convertor or flexplate. The 360 is externally balanced and has to have a
weight on the convertor, the 318 does not. People put these
transmissions behind big-block v8s in muscle cars, too, but that
requires an adaptor plate and significant modification.

Beyond that, there's the issue of the crossmember that supports the
tail-shaft. The 4-speed is fatter in the tailshaft area (that's where
the O/D was tacked onto the A-904 to create the A-500, or onto the A-727
to create the A-518). You may also have to massage the floorpan to clear
the fatter tailshaft, although with a ram truck it should be minimal. IT
gets pretty extensive for the folks that put these transmissions in
Darts, Valiants, and Barracudas, less-so for B-bodies, not much
difficulty for C-bodies, and virtually no problem for trucks.

And finally, there's control of the lockup convertor and O/D. In the
vehicles that originally came with an A-518 or A-500, the computer would
engage the locking TC and the O/D at the correct times. You CAN control
both with simple toggle switches that you operate manually, but the
danger is that if you improperly engage lockup or leave it engaged upon
coming to a stop, you can overstress and damage the lockup clutch.
Except for the very heavy-duty versions of the 518 that went behind the
Cummins or the V10, the lockup clutch is not meant to handle a great
deal of torque because the computer always disengages it when a lot of
torque is demanded from the engine. There are aftermarket controllers
intended for retrofitting these transmissions to muscle-cars that work
it all automatically based on throttle position and manifold vacuum, so
it would be best to consider that option.

 

Thank you!

I believe that the A500 was introduced to the Ram 250 Van in 1989,
sound right?

It looks like ithe A500's gearing is good for the the van's rear gear
(roughly 2.70, 1.50, 1.00, 0.70).

I do know that there's a lock-up converter in my 88's 3 Speed auto, so
perhaps it's ECM will control the A500's as well?

Should I assume that there's also a TV Cable of some sort (Throttle
Valve Cable to control pressure)?

So hopefully the swap only needs: A500, crossmember, driveshaft, and
TV Cable assembley?

Thanks again for your help!

 

Maybe... I'm a little foggy on the very early days of the 4-speeds. My
involvement with them came after the Magnum 318 and 360 came out with
MPFI and full electronic drivetrain control circa 1992.

Nope. The A904 (and its HD A998 and A999 versions) had a fully hydraulic
lockup control. The transmission operated entirely independently of any
external control other than the kickdown/throttle position linkage.
Driveshaft speed (determined by the governor) and input torque (implied
from the throttle position linkage) determine the shift points,
hydraulic pressures, and lockup point. Now the early A-500 *may* be the
same way as far as lockup is concerned- you'll have to find someone who
knows more about it in particular than I do.

Its a rigid linkage on Mopars prior to the Magnum series engines. It
runs from the carburetor (or TBI) down to the transmission. There are
two general versions- one with 3 semi-straight linkages coupled by
bellcranks, another that is a single rigid bar in applications where
there is room for it. The early Magnums use a cable from the MPFI
throttle body, later ones went to increasingly electronic controls of
everything until the A-500 and -518 were phased out completely in favor
of 100% electronic transmissions with the arrival of the 4.7 and 5.7 v8
engines.