Have you ever looked a manufacturers ID plate and wondered what all the letters and numbers mean? They are far from a random collection of characters. If you have the right key to decipher the meaning a whole world of knowledge can be accessed that will inform you of all the critical details. Certified Walter Snow Fighter nut Mike Bartlett has put together a comprehensive guide that will helpfully answer all of your questions. He has really done a great job and I’m happy to share his hard work with you all.

Cab

F – standard 72” wide cab set back ( has standard Walter manual transmission with integral transfer case and front bevel drive)

A – 84” wide cab advanced forward (has standard Walter manual transmission with integral transfer case and front bevel drive)

C – standard 72” wide cab set back with Allison semi-automatic transmission (has independent Walter transfer case and front bevel drive)

E – standard 72” wide cab set back with Allison fully automatic transmission (has independent Walter transfer case front bevel drive)

Q – 84” wide cab (set back) with Allison Automatic transmission (has independent Walter transfer case and front bevel drive)

N – new angled sided cab introduced in 1975

V – half cab used on twin engine airport model

S – set back half cab used on single engine airport model

Z – tilt cab used on Junior models

Engine

E – Waukesha GZ140 554 cid gasoline engine

G – Waukesha GK145 779 cid gasoline engine

W – Waukesha WAK 1197 cid gasoline engine

R – Waukesha/Roiline TH570 V8 gasoline engine

S – Waukesha/Roiline TH884 V8 gasoline engine

X – Hercules HXE 935 cid gasoline engine

H – Hercules gasoline engine

L – 391 cid Ford V8 gasoline engine (used in Junior models)

F – 534 cid Ford V8 gasoline engine

V – 702 cid GMC V12 gasoline engine or 637 cid GMC V8 engine

C – Cummins diesel engine (all models)

D – 8V71 Detroit diesel engine

K – 6V71 Detroit diesel engine

P – 6V53 Detroit diesel engine (used in tandem on airport model)

Chassis

N – 20000 GVW

M – 28000 GVW

K – 36000 GVW

B – 40000 GVW

G – 40000 GVW (high speed model)

R – 48000 GVW (B-model with 30,000 rear axle)

U – 54000 GVW

Junior Models (conventional Rockwell axles and Walter transfer case))

H – 28000 GVW, L – 33000 GVW, Q – 36,000 GVW

Wheelbase

A – less than 126” wheelbase

D – dumper 126” wheelbase

S – standard 138” wheelbase

L – long wheelbase 150”, 162”, or 174”

Notes

-The early Walters only used a 3 letter model code, all starting with F. At that time, all trucks used a Walter 5 speed transmission and a 6 cylinder flathead Waukesha so there was no letter for the engine. By the late 30s to early 40s, most trucks were built with the 6 fwd/2 rev transmission and an OHV engine and more engine choices were available so a letter was added to the code for the engine.

-Since the Walter manual transmission also has the transfer case and front drive in one unit, the main driveshaft rotates the opposite direction of the engine with the ring gear of the rear diff being on the passenger’s side and the ring gear on the front diff being on the driver’s side.

-Midsize B, K, and R models with an Allison automatic use a more compact 2 shaft transfer case and the half shafts out of transfer case also rotate the opposite direction of the engine with the ring gear of the rear diff being on the passenger’s side and the ring gear on the front diff being on the driver’s side.

-The large U model with an Allison automatic uses a larger and heavier 3 shaft transfer case the and the half shafts out of the transfer case rotate the same direction as the engine with the ring gear of the rear diff being on the driver’s side and the ring gear on the front diff being on the passenger’s side.

-Although the 3 Thruway G-models were a midsize chassis, they used the larger and heavier 3 shaft transfer case due to the smaller final drive ratio.

-Models using a manual transmission have inboard drum brakes on the front bevel drive portion of the transmission, conventional drum brakes in the rear, and inboard mechanical drum type parking brakes on the rear bevel drive. Models using an Allison automatic also have inboard drum brakes on the front bevel drive and conventional drum brakes on the rear, but the parking brake is a mechanical band type brake on the transmission (the Walter transfer case is a single speed transfer case).

-When the N-Series cab was introduced, Walter stopped building their own transmission as well as their 2 shaft transfer case. The 3 shaft transfer case with an Allison automatic became standard and a Fuller manual transmission was an also an option. Gas engines were dropped at this time in favor of diesel.

-Midsize K, B, G, and R models used either 11:00×24 tires with dual rear wheels or 12:00×24 tires with single rear wheels. The large U model used 14:00×24 with single rear wheels, but a few special production ones did have duals. The smaller M and N models used 8:25×20 tires. The junior models, with normal axles used 10:00×20 tires.

-GVWs and axle ratings did change over the years. These are mostly from the late 60s to early 70s.

-The twin engine airport model used 2 6V53 Detroits or 2 534 Ford V8s and 2 Allison automatic transmissions and a the 3 shaft Walter transfer case with the front engine and tranny coming in on the input shaft of the transfer case and the rear engine and tranny coming in on the countershaft.

-The single engine airport model uses a setback halfcab with an 8V71 Detroit or NTC-350 Cummins and a heavier duty Allison automatic.

Mike has also supplied me with a running narration of my video shot at Dobbins Auto Parts a few years back. I’ve provided his notes as annotations so please feel free to watch again.