Had a previous thread on the yoke replaced on my 63 diff. As Joe Lucia explained below it changed because of the new and different spline. I took a good look at it today and it does have a GM stamp on it. But I couldn't locate any part numbers.
The issue is the cup behind the yoke. On the original it has a recess to it. The new one sits flush up against the diff. Big deal, no, but don't like.
Spoke to the shop today and they are going to exchange it for the correct part number below.
Thanks Joe!!
Previous response from Joe Lucia:
"Joe-----
The reason for the need to change the pinion flange is that original 1963-64 Corvette differentials used a "coarse spline" pinion shaft. I don't think that anyone produces R&P gearsets for the 63-64 spline configuration anymore. GM ceased many years ago.
So, if the gears were to be replaced, then the 65-79 style pinion spline gearsets had to be used. These are the only ones currently manufactured by sources like Richmond Gear and U.S. Gear.
The change to the 65-79 style pinion spline also requires a change in the pinion (companion) flange. The flange configuration that you described is new to me. I've not seen a 65-79 pinion flange of that configuration. Essentially, the 65-79 pinion flange is configured like the 63-64. However, the 63-64 flange is unique in cross section and you will not find a 65+ style flange exactly like it. However, as I say, the 65+ style flange is more-or-less configured like the 63-64 and does have the cupped shaped deflector and fits to the housing just like the 63-64. The GM flange is GM #3878972 and is still available from GM for a current list price of $96.44. All I can figure, based upon your description, is that the flange you have is some sort of aftermarket piece. "
Joe's 63 FI Convertible
The issue is the cup behind the yoke. On the original it has a recess to it. The new one sits flush up against the diff. Big deal, no, but don't like.
Spoke to the shop today and they are going to exchange it for the correct part number below.
Thanks Joe!!
Previous response from Joe Lucia:
"Joe-----
The reason for the need to change the pinion flange is that original 1963-64 Corvette differentials used a "coarse spline" pinion shaft. I don't think that anyone produces R&P gearsets for the 63-64 spline configuration anymore. GM ceased many years ago.
So, if the gears were to be replaced, then the 65-79 style pinion spline gearsets had to be used. These are the only ones currently manufactured by sources like Richmond Gear and U.S. Gear.
The change to the 65-79 style pinion spline also requires a change in the pinion (companion) flange. The flange configuration that you described is new to me. I've not seen a 65-79 pinion flange of that configuration. Essentially, the 65-79 pinion flange is configured like the 63-64. However, the 63-64 flange is unique in cross section and you will not find a 65+ style flange exactly like it. However, as I say, the 65+ style flange is more-or-less configured like the 63-64 and does have the cupped shaped deflector and fits to the housing just like the 63-64. The GM flange is GM #3878972 and is still available from GM for a current list price of $96.44. All I can figure, based upon your description, is that the flange you have is some sort of aftermarket piece. "
Joe's 63 FI Convertible
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