904 dual pumper

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grr8_65

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A few years ago when I had my /6 rebuilt in my 65 cuda, I had the tranny done also. The shop quoted me for a 904. When I picked the car up ( I didn't really pick the car up, I didn't want to show off) they said it had 2 pumps, 1 in front and another in the rear. Said they should have charged more for the 2nd pump but didn't quote it that way and only charged me what they originally quoted and still bedid the 2nd pump.

Said all that to ask, is there any advantage or disadvantage to this unit? From what I have be able to gather, the rear pump would allow the car to be pushed to start.

Thanks for any info. Tom
 
The only advantage is so it can be push started or towed without removing the driveshaft. Disadvantages are more moving parts to wear out and cost more to rebuild.
 
At least it didn't cost you more to get it rebuilt.

As I recall, the shop manual says to push the car to 40 mph in 2nd gear with the ignition on to start (or you could roll down a hill). I have 3 pre-1966 Mopars like that. I think the 2 pumps went with the cable shift design.

I expect push starting and towing were not the reason for the 2 pump design. It probably was superior in some technical way and was dropped as a cost savings and/or to prevent owners from push-starting (lawyers). As time passes, the manufacturers often cheapen a design, such as going to cast cranks, stamped rocker arms, fewer bolts, etc. "They don't make it like they used to" often has truths.
 
Bill they did most likely drop them because it's cheaper to build them with one pump but the original design was in fact to make it possible to push start the car. You have to remember that batteries were not as reliable in those days so push starting was a really nice feature. If you have proof that they are superior I'd like to see it as I like to learn about torqueflites. Been rebuilding them for stock and perf. use over 30 yrs. but there's always more to learn.
 
If for some strange reason you decide to swap from a 1- to a 2-pump Torqueflite or vice versa, it means you have to spend the money, time, and effort to also get the shifter (twin-cable for 2-pump, single-rod for 1-pump) and driveshaft (flange-type output on 2-pump, spline-type output on 1-pump) and speedometer drive (totally different) that goes with the transmission you're swapping to. Makes very little sense to do this swap in either direction. '60-'65 cars have 2-pump/cable-shift Torqueflites. '66-up cars have 1-pump rod-shift Torqueflites. Both designs work fine. Neither is materially advantageous over the other except that the '66-up rod-type shifting means fewer leak points and easier adjustment. Push starting, yeah, on the 2-pump transmissions, but that's of no great importance most of the time. If you have a 2-pump transmission, make sure it's equipped with the 2-port filter or you'll starve and damage the rear pump.
 
Thanks for all the input. Can't have too much information about the system, Mom and Dad bought the car new and I am going to make it over into a almost daily driver. As I said this is the original trans and I don't plan to change it under normal conditions.

May everyone have a blessed day.
 
As usual, Dan the Man comes through with all the good information. Thanks Dan, you really are a wealth of information.
 
Well I learned a few things today. Good luck with the car.
 
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