My recollection is that there are two different pinion shaft diameters
The ’55-’58 Parts Manual shows the parts numbers below for the front oil (pinion shaft) seals. The pinion shafts get progressively larger and the tightening torque on the flange nut is 240 ft-lbf for the 8.25” gear set vs 250 ft-lbf for the 8 ¾” & 9 5/8” gear sets. It might be helpful to the parts-person to indicate the seal for your 300 is also the same one for a NY, Imperial or a wagon.
663602: ’55-56 Windsor, except Estate Wagon or ’56 with Power Package (4-bbl?) 8 ¼” ring gear
1404504: ’55-’56 Windsor wagon, NY, C-300 & Imperial, ’56 Windsor with Power Package (4-bbl?) 8 ¾” ring gear
587541: ’55 Crown Imperial (with 9 5/8” ring gear). Who knew? Truck diff?
Axle seals are the same across the board for Chrysler sedans with different seals for wagons and Imperials. Thicker axles?
Application data is complete for ’55-56 but some is missing for ’57-58 in this October ’57 manual update.
Something that has helped me in the past is being able to provide the original Chrysler part number. Advance Auto, NAPA, etc has been able to plug in that number and cross reference it to currently available parts.
----- Original Message -----
Sent: Friday, July 08, 2016 12:11 PM
Subject: [Chrysler300] Rear Pinion Seal
The rear pinion seal took a crap on my 55, so I took the easy way out and ordered the “correct” seal from Rock Auto. Turns out it’s not the right part and other online stores like Advance and Auto Zone also sell the same wrong seal (#7216). The seal had a number of 6845 and the mechanic I had do it couldn’t get that from anyone. I called NAPA and they had nothing listed for a 55 300 at all, but they did end up ordering the seal for a 55 Imperial and low and behold it’s the correct seal #21336. The good news is that the mechanic charged me $100 out the door. My Dad thought that was pricey, but he wasn’t the one that was going to be doing the work… Just sharing in case lightning strikes twice.
Hopefully I will see some of you at Carlisle next week. My Dad and I will be on the show field.
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