Posted by Clint Dixon on Wednesday, September 25, 2002 at 12:00PM :
In Reply to: which tranny on a '49 PW? posted by Ryan McNabb on Tuesday, September 24, 2002 at 10:08PM :
Ryan. I do not think that either of the two spur gear transmissions have a model number. The '46 to'51 is most commonly referred to as the "up to type". The '51 to '56 is called the "after type". The easiest way to tell the two apart is that the "up to type" has the hole for the drain plug entering the rear bottom of the case at a slight incline up and towards the front of the truck. The "after type" has this hole parallel to the bottom of the case. Just about everything is different between these two transmissions that can be. They have a different case, gears, and bolt pattern for the case cover. They also take different PTO assemblys.
I believe the "up tp type" was also used on the WWII WC series. I have been told the "after type" was a carry over from larger trucks from the '40s. I do not know how they compare in durability to the NP420, but it is common for the "after type" to have problems with third gear.
Clint
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