Pilot House Cab Differernces

[JBNeal]

I found the paragraph that speaks of "...a heavy transverse member that was welded to the lock pillars and the underbody pan to provide a rigid tie between lock pillars and underbody."  I'm guessing this observation was made from sales literature that was available at the time.  I got curious and observed a few differences among the years between the seat base & b-pillar, as well as the rear cab mounts.  The rear cab mounts are different for '53, but if anything, they look smaller...if there's a transverse member under there, I sure don't see it while the cab is mounted on the frame. 

 

'53 rear cab mount

 

'51 rear cab mount ('48-'52 similar)

 

The filler plate at the seat base changed from early '48 to '49, then again by '51, and again for '53.  A hole shows up in this plate by '49, but disappears for the '53s...dunno what its purpose is or why it's only on the driver side.  

 

'53 filler plate

 

'51-'52 filler plate

 

'49 filler plate

 

early '48 filler plate

Edited September 3, 2021 by JBNeal
revised pictures

[JBNeal]

a few other details are of note, such as the B-1 roof rail vs. the B-3/B-4 roof rail profiles, as well as the door sill cab seal.  The B-1s had a seal mechanically attached with clips to holes in the groove in the door, while the B-3/B-4s are mechanically attached to the cab sill that aligns above the door groove.

     

 

 

Edited September 3, 2021 by JBNeal
revised pictures

[JBNeal]

I looked in the parts manual to verify that there was a change to the lower toe board and transmission cover, and it appears that there was a serial number break in the B-2s for the updated parts.
B-1/early B-2 (3spd shown):

later B-2/B-3/B-4 (3spd column shift shown):

Edited September 3, 2021 by JBNeal
revised pictures

[JBNeal]

additional information - Air-O-Ride control tag

[JBNeal]

There appears to be another small change in the cabs from '48 to '49 in the door upper hinge area.  The '49-'53 cabs appear to have a stiffener added in this area...hard to see, but it's up in there...

 

    

Edited August 22, 2021 by JBNeal
revised pictures

[Vet Doc]

During mixing and matching door parts, I discovered that the hinge bolt diameter changed from 5/16” to 3/8” from ‘48 to ‘49. Both have 9/16 heads and 24 tip fine threads; the hinges have matching slot diameters. Also, the ‘49 hinges have been stiffened with a pressed bend in the center of the metal.

 

I am considering using the ‘49 hinges because they should be stronger/stiffer, but I’m not sure how the bolt diameter and slot size difference will affect functionality.  In theory, there should be more adjustability, but there may be more sloppiness for the bolts to keep the adjustment secure.

[JBNeal]

additional information - Door Hinge Information

[JBNeal]

Rear cab mounts on the '48 and '49 had plugs in the cab floor.  The seat mounting frame looks to brace the cab floor with a filler plate to the B-pillar.

 

Rear cab mounts on the '51 and '52 were similar, but I could not find plugs in the floor.  The seat mounting frame was extended and looks to brace the cab floor as well as tie the B-pillars together.

 

Rear cab mount on the '53 were a bit different, with no floor plugs as the longer bolts go through the cab floor.  The seat mounting frame is integrated into a straight brace with gussets that ties the B-pillars together, which might be the transverse member that Bunn described in his book.

[JBNeal]

I had noticed years ago that the '49 seat seemed like it sat lower than the '48.  The '49 definitely rode smoother from its 126" wheelbase vs the 108" wb of the '48, but even stationary, the '48 had a firmer seat cushion.  Eventually,  I looked at variations on the Pilot-House cab seats, and I did notice a variety of small changes in seat cushion springs, seat backs, etc but finally remembered to measure the seat frames a little bit...

 

'48:

 

'49:

 

'51:

 

'53:

 

additional information - factory seat options

[bkahler]

9 hours ago, JBNeal said:

I had noticed years ago that the '49 seat seemed like it sat lower than the '48.  The '49 definitely rode smoother from its 126" wheelbase vs the 108" wb of the '48, but even stationary, the '48 had a firmer seat cushion.  Eventually,  I looked at variations on the Pilot-House cab seats, and I did notice a variety of small changes in seat cushion springs, seat backs, etc but finally remembered to measure the seat frames a little bit...

 

'48:

 

'49:

 

'51:

 

'53:

 

additional information - factory seat options

 

Very interesting observation.  I never realized there were differences in this area of the cab.