Older Chrysler third memeber case numbers

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Slantsix64

Slantsix64

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hi guys I'm trying to find out the older Chrysler third member 8.75 case numbers, I know of the newer ones 741 742 489, but what are the older gears case numbers the ones that cam with tapered axles
 
Slantsix64 said:
hi guys I'm trying to find out the older Chrysler third member 8.75 case numbers, I know of the newer ones 741 742 489, but what are the older gears case numbers the ones that cam with tapered axles
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I have a 64 with the tapered axles. its a 741 case. the 741 case dates back to the original 8.75. So MOST of the tapered ones are likely to be 741s
 
I believe there was a 488, same as the 489. But some of the old ones had a thrust block difference.
 
dukeboy_318 said:
I have a 64 with the tapered axles. its a 741 case. the 741 case dates back to the original 8.75. So MOST of the tapered ones are likely to be 741s
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Oh okay thanks, so how would I know it's it's an older gear set? 741 case
 
Demonic said:
I believe there was a 488, same as the 489. But some of the old ones had a thrust block difference.
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Yes that's the number. Because I have green bearings and those gears will fit right in, with out me having to take the pins out of the later gears
 
From bigblockdart.com

Everything You Ever Wanted To Know About The 8 3/4 Axle

The 8-3/4" axle was available in three basic types. The types are differentiated by the pinion stem diameter....1-3/8", 1-3/4", 1-7/8". The choice of axle pinion assembly was determined based on the application.

1-3/8" small stem pinion... (aka. '741')...
Carrier casting numbers: 1820657 (1957-1964), 2070741 (1964-1972). This assembly was typically used in low weight/low horsepower applications through low weight/medium horsepower and high weight/low horsepower applications. Pinion depth and bearing preload is set with shims. Differential bearing setting (ie. backlash ) is set with threaded adjusters.

1-3/4" large stem pinion... (aka. '742')...
Carrier casting numbers: 1634985 (1957-1964), 2070742 (~1961-1969). This assembly was replaced by a phase-in of the 1-7/8" pinion starting in the 1969 model year. 1970 RW (Plymouth and Dodge mid-size) were the last models to use the 1-3/4" which appeared in a 2881489 case. This assembly was typically used in high weight/medium horsepower applications through high weight/high horsepower applications. Pinion depth and bearing preload is set with shims. Differential bearing setting (ie. backlash ) is set with threaded adjusters.

1-7/8" tapered stem pinion... (aka. '489')...
Carrier casting numbers: 2881488, 2881489 (1969-1974). This assembly was introduced in 1969 and was phased-in to relace the 1-3/4" unit through 1970. Note: the 1-3/4" pinion also appeared in some '489' carriers during this period. By 1973, the '489' was the only unit available in passenger car applications. This assembly was typically used in high weight/medium horsepower applications through high weight/high horsepower applications. Pinion depth is set with shims, preload is set with a crush sleeve. Differential bearing setting (ie. backlash ) is set with threaded adjusters.
 
Slantsix64 said:
Oh okay thanks, so how would I know it's it's an older gear set? 741 case
Click to expand...
date codes. that or look to see if it has thrust blocks. Some of the Pre 62 versions had thrust blocks in them.
 
There are some other case numbers, back to 1957 IIRC.
 
1957-1964 8-3/4" Carrier casting numbers are 1820657
They had the 1-3/8" small stem pinion like the 741 case.
 
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