rear drive shaft help

[F-ingrob]

i have an 87 K5 with a 14bff and a 4" lift and 35" tires
the rear drive shaft is a bit too short and i read on here that some one used the double u joint off a fren drive shaft to make up the length and it also helped the the angle
the double u joint set up is the amount of length i need to add
so will this work or am i smokin crack

 

[diesel4me]

I could be wrong but you'd probably have to use a driveshaft off something like an old caddy that had CV joint yokes (some had them on both ends!) ,because there is a centering ball and socket needed to keep the CV yoke from flopping around,and the ball stud part of it is made to the driveshaft,same as the front shaft on a 4x4 has..you cant just add a CV yoke and 2 u-joints to a regular driveshaft,it would whip around and self destruct I'd think..

I doubt the same u-joints will fit off a front shaft VS the rear too,they are probably different sizes...probably easier to have your driveshaft lengthened or find a longer one from a longer wheelbased truck like yours and shorten it..its easier to shorten one than make one longer..

 

[sweetk30]

DO NOT use caddy c/v stuff . bad things will happen from what I have read and seen over the years.

but yes you need a retube for longer length or just coin up and do a c/v head shaft and be done with it for less vib's and or chance of vib's on the short w/b blazers.

 

[Blue85]

No, you can not use parts from the front C/V to create a C/V on your rear drive shaft. They are different series U-joints and there is no way to have the centering ball. Plus, keep in mind that if you swap from a standard joint to a C/V you will have to change the angle of the pinion.

Some have used rear drive shafts from a Super Doody, which will need to be shortened. I don't know if the yokes are correct otherwise. You could also try a shaft from a SWB Chevy, which may end up being too long. The advantage to that over your too-short shaft is that a DIY can potentially shorten up a shaft themselves.