An unusual 91 5.9 four speed

[MidwestMotorman]

I ran across (and bought) and unusual 5. 9 gasser last weekend. It was a 91 W250 4x4 extended cab with a 5. 9 EFI Z code motor, a four speed, 3. 55 geared Dana 44 front and Dana 70 rear, and a 241 transfer case. It had been owned by the same owner since 93 when he bought it off a dealer lot as a trade in for the "new" 94s. I have run across these four speeds before up to 85, but have never seen one after that. How unusual are these four speeds? The first three gears are pretty steep and there is a big jump from 3rd to 4th.



The truck is very rust free which is pretty rare for an Iowa truck. Probably due to the fact that it was parked indoors and mechanically maintained. It has the newer style directional chrome rims from a 96. What amazes me is the power and mileage I get. The worst is 13mpg and the best is 16 with no tuneups done yet. This truck puts to shame a 90 W250 heavy duty I previously had also with a 5. 9 gasser EFI, auto overdrive and 4. 10 gears.

 

[MBergman]

91 was the last year of the NP435 4-speed in the Dodge trucks. They were very common in fleet trucks, such as ones used by the Forest Service. My 91 is a standard cab with 4. 10's, Dana 44 front, and Dana 60 rear. I wish it got the mileage you are getting... a whopping 12mpg on the highway is what I was getting with the 4-speed, and it gets almost 14 now with the 5-speed. Been a very good truck for me, so I may not mess with it too much. Sure is lacking some power though.



Marc

 

[MidwestMotorman]

I am sure my mileage is attributed to the 3. 55 gears, but you should have seen more improvement with the five speed's OD. My 90 with 4. 10 and auto OD got 14 if you drove a constant 75mph and about 9-11 in daily driving, and it was a total DOG on power. I couldn't tow with OD on and had to keep my foot in it to maintain 55mph loaded (about 9k towing behind and I had the truck in top tune). How much work was it to convert to the five speed? It is interesting that you have the Dana 60. My 90 HD 3/4 only had the Dana 60, but this 91 has a Dana 70 center section with what looks like Dana 60 axle tubes. My drives the best of any first gen I have owned. The previous owner converted the steering to a ujoint system and everything is nice and tight.

 

[MBergman]

My mileage may be attributed to a plugged up cat, which should be taken care of this summer. Converting over to the 5-speed was just a bolt in, and moving the hole in the floor for the shifter.



Marc