1965 Big block corvette differential removal

[Brenton M.]

I'm close to finishing a frame off restoration on my 1965 Big block but was very dissapointed a few days ago when i drove it out side of shop to hear a rubbing sound it turned out to be the Diff.Yoke rubbing underneath the drive shaft tunnel. it measured 4.25 i think the one i need is 3.75 that sucks. would some one tell me what is the best way to drop the Differential down to replace the yoke with the correct one.

[Wayne M.]

Re: 1965 Big block corvette differential removal

You probably have the 1330 series yoke, cast "9210" and "GM". But you also have to do something with the U-joint and/or the drive shaft yoke to match the smaller (original) 1310 series, cast "986".

[Joe L.]

Re: 1965 Big block corvette differential removal

You probably have the 1330 series yoke, cast "9210" and "GM". But you also have to do something with the U-joint and/or the drive shaft yoke to match the smaller (original) 1310 series, cast "986".

Wayne-----


It is possible that a conversion u-joint was used to adapt an original 1965 driveshaft to a differential with a 1330 series pinion flange installed. However, if that was done it should be obvious by looking at the u-joint for an asymmetrical configuration. If regular 1330 series u-joint was used then the driveshaft yoke will need to be changed or a new driveshaft obtained.

[Joe L.]

Re: 1965 Big block corvette differential removal

I'm close to finishing a frame off restoration on my 1965 Big block but was very dissapointed a few days ago when i drove it out side of shop to hear a rubbing sound it turned out to be the Diff.Yoke rubbing underneath the drive shaft tunnel. it measured 4.25 i think the one i need is 3.75 that sucks. would some one tell me what is the best way to drop the Differential down to replace the yoke with the correct one.

Brenton-----


If the differential has a 1330 series pinion flange installed, then I would strongly suspect that it's not the original unit installed in the car. I just don't see any reson why anyone would change an original 1310 (old 1280) series pinion flange to a 1330. However, there's a very good chance that a REPLACEMENT differential unit might have a 1330 series pinion flange installed.

You can change the pinion flange while the unit is installed in the car without the need to drop it. You will, however, have to remove the driveshaft and differential pinion snubber bracket.

I'm a little surprised, though, that the 1330 series u-joint hits the tunnel. Are you sure the car doesn't have a broken "spine"? This is the most common cause for the driveshaft/pinion flange to hit the tunnel.

[Brenton M.]

Re: 1965 Big block corvette differential removal

Thanks for the information Joe, Could you explain to me what a broken spine is? Yes i do think this unit has been changed i dont think its a 65 unit.

[Joe L.]

Re: 1965 Big block corvette differential removal

Thanks for the information Joe, Could you explain to me what a broken spine is? Yes i do think this unit has been changed i dont think its a 65 unit.

Brenton-----


Basically, it's a crack and subsequent deformation in the underbody panel of which the tunnel is a part.