Conversion joint

[BLT-71]

My car in its history had the rear end replaced. When this was done they used a smaller yoke at the rear, the driveshaft has a larger size. Question is this an easy replacement and what is the cost for another larger yoke. And is there anything else that I should replace while replacing it??? Thank you in advance! 71 LT-1

[Joe Lucia (12484)]

Re: Conversion joint

BLT-71-----


1965 through 1970 Corvettes with manual transmissions used companion flange GM #3878972. This is a 3-27/32" diamter flange and is the "small flange". In 1971 the companion flange was changed to GM #3879208. This is a 4-5/16" flange and is the "large size". The latter flange is the one that you need if you are to use a stock, 1971 driveshaft and u-joints. Otherwise, you will require a custom-made driveshaft which uses the large size u-joint for the transmission yoke and the small size u-joint for your "small" differential companion flange. The GM #3879208 companion flange is still available and GM lists for $80.00.


Unfortunately, the companion flange is not so easy to change. That's because the pinion bearing preload is controlled by a crush sleeve and the torque applied to the pinion nut.