What's the difference between an SD38 and an SD38-2?

Model Railroader Prototype information for the modeler
1

With anticipation of my DMIR SD38-2’s showing up, I was wonderring what the major differences between SD38’s & SD38-2’s. I’m aware of different trucks and fuel tank size specific to Missabe engines but wonder if there are obvious visual differences that would stop me from calling my SD38-2 an Sd38.

Thanks, Rich

2

The SD38-2 is longer than a straight SD38 and there is a water level sight glass window in the side of the hood on an SD38-2. There may also be differences in the fans, grills and air intakes, depending on when the various units were built.

Dave H.

3

Any idea how much longer?

Thanks, Rich

4

I think an SD38-2 shared a common SD40-2 frame

5

SD38-2’s, SD40-2’s and SD45-2’s all share the same frame. Another major spotting difference is the HTC trucks under the SD38-2 versus the SD38’s Flexicoils. the HTC’s have slightly uneven axle spacing, three holes in the sideframe on each side of the center axle and an extension of the sideframe on the fuel tank end of the truck.

6

I don’t have the foggiest idea but I do know whatever it is there are two of them! [:D]

7

The SD38-2 has twin exhaust stacks for it’s non-turbocharged 16-645 prime mover.

8

An SD38 also had twin exhaust stacks, for the same reason.

9

The HTC truck on the dash 2’s also has a damping shock absorber

10

You’re right, Roger, I forgot that about the center axle shock completely…it’s a more obvious spotting feature than the others I mentioned. Doh!

11

I used an Athearn SD-40-2 to bash into an SD-38-2. (B&LE 891) I added a paper air filter and used the dynamic fans from a GP-38-2 (there was a lot of sanding and filling) to have both Dynamic fans match the fans on the rear. I studied the pictures and found that the main differeces are the different fans and the paper air filter. Yes the trucks are different HTC VS Flexicoil and a different door arragemnt (but not enought to worry about) I plan to bash more SD-38-2s Its a great looking engine.

12

Rich,

There are a few standard differences between the SD38/40 and the SD38/40-2’s.
The dash2’s are 3 feet longer (they use the same chassis as the SD45-2). This extra length comes from EMD going with the HTC Hi-Adhesion trucks instead of the Flexi-coil used on the SD38/40’s. The HTC trucks a damping struct on the center axle. This 3 feet of length shows up as larger porches at the rear and front of unit. One result of this length is that the last wheel of the rear truck extends completely out from the under the hood.
The dash2’s also have a oblong water sight glass.
There are also access holes in the rear of the long hood for radiator piping.
They also have eaves over the back of the cab.
You can see the differences in the photo of UP SD40-2 #3434 compared to the photo of EMD SD40 #6506.

Dan

13

i have to agree and nice pic

14

As I understand it, EMD used the same frame for all 3 models because they felt it was cheaper to use one common frame than 3 different ones. The length was not necessary because of the trucks, but because of the 20 cylinder engine in the SD45’s. That’s why an SD45’s hood extends virtually the full length of the frame (minus the walkways on the ends), versus the “porches” on the SD40’s and SD38’s. Another reason was that the SD45’s were fuel hogs, and the larger fuel tank was something of a necessity.

Brad