I am interested in the changes to the driveshaft and yokes at either end of the driveshaft between model year 1970 and 1971 Corvettes. Could someone elaborate on these differences especially regarding the M-21 big block optioned Corvettes? I'm trying to bring mine to the way it was originally. Thanks.
-
Tony -
Re: C3 Trans/Differential Yokes -70 vs 71+
the yoke is 26 spline on 71 cars -
Re: C3 Trans/Differential Yokes -70 vs 71+
Tony-----
1970 Corvettes with Muncie 4 speed used output yoke GM #3868728. This is a 26 spline yoke designed for use with a 1280 series u-joint and of 3-27/32" diameter. The differential pinion flange was of GM #3878972 and was also designed for use with the 1280 series u-joint. The driveshaft was designed to accomodate the 1280 series u-joint on both ends. U-joints were retained to both the transmission yoke and pinion yoke by U-bolts with nuts. The driveshaft is 31-1/4" end-to-end.
1971 Corvette with 4 speed (or THM-400, for that matter) used a transmission output yoke of GM #3930827. This is a 32 spline yoke designed for use with a larger finger diameter u-joint (I forgot the series---it might be 1320 or 1330) with a diameter of 4-5/16". The differential pinion flange is a GM #3879208 and is designed for the same u-joint. The u-joint is retained to BOTH the transmission yoke and the pinion yoke by steel straps with hex bolts. The driveshaft is ABOUT 3/4" shorter than the 1970.
All of the aforementioned GM part numbers are discontinued.In Appreciation of John HinckleyComment
-
Re: C3 Trans/Differential Yokes -70 vs 71+
lyndon-----
The last use of a 26 spline OUTPUT shaft on a manual transmission Corvette was 1970. For 1971-75, ALL Corvette transmission output yokes, manual trans or automatic, were 32 spline.In Appreciation of John HinckleyComment
-
Re: C3 Trans/Differential Yokes -70 vs 71+
yeah I dont know why we can not edit a post on here I meant that 70 had 26. I just have 71s on the brain all the time dont know why.Comment
-
Re: C3 Trans/Differential Yokes -70 vs 71+
Lyndon,
To edit your post, click on preview, then in the message area edit and either preview or post your correction to the bulletin board.
David Nims #19639Comment
Comment