A833 real seal and reverse indicator switch

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Duster_Dean

Duster_Dean

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Hi all, I recently picked up a 1975 Duster that was orginally a slant 6 auto. It's been through a number of owners and over the years it has become a 383 magnum, 4 speed. I've begun going through it and some of the many issues it has includes a leaking rear seal on the trans and a leaking o-ring (I believe) from the reverse light signal sender. My questions are 1.) Do all A833 4 speeds have the same rear seal size and type? The markings on mine show C 99129M (cast into the trans) and a stamped number of PT6355037CP. My novice decoding of the cast in numbers indicates this was used from 1969 - 1971. And 2.) what is the proper description of the reverse signal sender so I can look it up to order a replacement. Any further advice on the replacement of these two items is always appreciated. TIA
 
I think all the 4 speeds used the 727 size rear seal. I like the ones with the rubber boot on it. The seal for the switch is just a really thin round gasket.
 
Not counting the '64/'65 ball and trunnion units which don't apply here, all long tail (B, C, E, some trucks) 833s from '66 onward had 30 spline output shafts, same as a 727.
A (and later, F body) short tail 833s had a smaller diameter 26 spline output (same as a 904) in '66/'67, except for the mid-year '67 383 GTS and Formula S cars, which got the first of the short tail 30 spline output shafts. In '68 and later years they went to 30 spline across the board.
The reverse sender uses what amounts to a crush sleeve to seal it.
 
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A leaking rear seal is usually one of three possibilities. The seal itself, worn tail shaft busing or a leaking yoke end cap.
 
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