C20 driveshaft shortening

[Jackrabbit760]

Hey there fellas I got a few questions I'm hoping you guys can answer for me. I have swapped out the old eaton for a dana 60. Seems that i will have to shorten the driveshaft some. I pulled the trigger rather quickly and cut the yoke of the rear driveshaft I hope that wasn't a mistake. It's a 2 piece so I'm wondering what shaft would actually need the shortening. Also I have the truck on jack stands under the chassis a couple inches forward from the axle and have my jack under the axle will this give me a false reading when determining how much to shorten on the driveshaft ? Should the truck be sitting on all 4 wheels instead? The truck is a 66 c20 with coil rear end and trailing arm suspension 4 on the floor granny. Thank you much and look forward to seeing some replies.

[Captainfab]

You will need to shorten the rear driveshaft. You will want weight on the rear wheels so that the differential is at ride height. Then you can measure. Usually the driveshaft/machine shop will prefer to do the cutting themselves.

[Jackrabbit760]

Originally Posted by Captainfab

You will need to shorten the rear driveshaft. You will want weight on the rear wheels so that the differential is at ride height. Then you can measure. Usually the driveshaft/machine shop will prefer to do the cutting themselves.

Thank you captain. Guys let me just say that I purchased some trailing arm brackets or perches from captainfab to weld on my dana 60 and they fit great not to mention quality wise they were top notch. I got a little to excited after watching some YouTube videos on how to cut and shorten the driveshaft. I cut right behind the weld just enough to break it with a hit of my ball pin hammer on the shaft tube, popped right out. As far as the re welding and balancing I will definitely have a professional shop do it. Is there anything else I should keep in mind guys? Thanks

[Jackrabbit760]

Been busy with work and haven't had the opportunity to take the driveshaft into the shop nor have I had the time to shorten it. I measured the shaft where the driveshaft will enter and I got about 3 1/2 inches. Should there be some play? Let's say I have to shorten the driveshaft by 2 inches should I shorten by half inch or more so it can have some wiggle in and out ?

[Captainfab]

What you want to do is remove the front slip yoke from your rear driveshaft. It needs to come off anyway. Then slide it onto the splines of the front shaft and bottom it out. Now pull it back 1" to 1-1/4". Then measure from the center of the U-joint bore on the yoke to the flat on the pinion yoke. That is the length you need the rear driveshaft.

[Jackrabbit760]

Originally Posted by Captainfab

What you want to do is remove the front slip yoke from your rear driveshaft. It needs to come off anyway. Then slide it onto the splines of the front shaft and bottom it out. Now pull it back 1" to 1-1/4". Then measure from the center of the U-joint bore on the yoke to the flat on the pinion yoke. That is the length you need the rear driveshaft.

Captainfab once again you come to the rescue... Thank you sir