Chevrolet 1533X2 30-cwt trucks

[Colin Alford]

Gents,

While I have never been particularly interested in MCP vehicles, I now realize that I have access to some manuals that can very likely answer some of the questions that have been posed on this forum.

The reason it took me this long to realize is that I looked at these as CC60L manuals, and didn’t make the connection to the Chev model numbers 1542, 1543, etc.

I will attempt to provide some assistance.

Colin

[Colin Alford]

Since this thread is primarily about 1533X2, but no-one seems to have a parts manual for it, let’s start by using the Major Assemblies book to see what vehicles shared the same major components as 1533X2.

Here is the data regarding engines for Chev MCP vehicles.

Both 1533X2 and 1543X2 used engine assembly 5269525. It appears that the significant difference between this engine, and other MCP engines, was a six-bladed fan, with a spacer between fan and pulley.

[Colin Alford]

Transmission,

While the transmission was visually similar to other CMP and MCP types, if we look at the bottom of the conversion chart, only 1533X2 and 1543X2 used the same speedometer drive gear.

[Tony Smith]

Originally Posted by Colin Alford

Transmission,

While the transmission was visually similar to other CMP and MCP types, ... only 1533X2 and 1543X2 used the same speedometer drive gear.

Because the Speedo Drive gear ratio has to be related to the specific Differential Ratio and tire size.

1531 and 1541 had 6.16:1 gears and 17" wheels
1542 had 6.16:1 gears and 20" wheels
1533 and 1543 had Eaton 2 speed diff and 16" wheels.

The Eaton final ratio was dependant on the particular ring and pinion gears fitted with a fixed reduction in the 2 speed gears. Typical ratios of the 40's were 5.83/8.11 and 6.33/8.81 ratios. Note that the Hi ratio in either of these combinations is not the same as the 6.16 of the Chev differential, so a unique speedo drive gear ratio has to be use with the Eaton.

Now if Bob Carriere would be so good to look in his 1543X2 parts manual, we might determine the actual diff ring/pinion ratio.