Front driveshaft

[Kraig]

I have had a bad double cardan joint on it. I found a shaft on rock auto and bought it. Fast forward through the last year of craziness and I finally put it on. It's too long! I purchased (and double checked on every website I can find) the right part but the length says 38 1/4" long. Mine measures around 36" from base if the yoke (where the ujoint rides) to base of yoke.

If I cannot return this I will be forced to have it shortened so as a side question, could someone direct me to the proper method of measuring the shaft for proper fit?

 

[DaveBen]

I have always gone from the center of the U-Joint to center of the other U-Joint for the working length. I have had driveshafts made for trucks and Jeeps. Always worked for me.

 

[u2slow]

IME, it's eye to eye on the ujoints, usually compressed. Unless it has a flange, then flange face is used.

 

[Kraig]

I was just wondering how much I need to give as far as I know what the center to center is with the truck sitting on the ground but surely that's not the compressed measurement. Shouldn't it need to have more compression capacity for bumps and such? I didn't know if there was a method to the madness of proper driveshaft measurement

 

[greenskeeper]

a1driveshaft.com is where I get all things 4x4 made, and their measurements ask for center u-joint to u-joint distance.

 

[u2slow]

Lengths depends on the context.

A shop making one needs one set of criteria. An auto wrecker is measuring it after its out of the truck; probably compressed. What a new jobber part is going by.... who really knows?

With the front shackle arrangement, I don't suspect the shaft compresses much with suspension travel.

 

[Kraig]

Ok so if the shaft won't compress during driving then I need to go by exact measurement from yoke to yoke while the truck sits on level ground. Correct?