Which Driveline?

[vindemiate]

A few weeks after I had a 6" lift installed my rear driveline started to shudder when depressing the skinny pedal. Took it to a shop and was told the pinion angles were off. OK. I purchased some shims and installed them and walla... still shudders. After inspecting closely, I found the front U-joint was toast.

I was planning on having the driveline extended anyway to account for the lift but now I was thinking of replacing the whole thing. What would be an appropriate driveline for a 90' K5 with a 6" lift? I want to run 35"-37" tires and do modest trail driving. No rock crawling.

Also, if I plan to move the axles out another inch to inch and a half, would the axle have to change again?

 

[dremu]

Also, if I plan to move the axles out another inch to inch and a half, would the axle have to change again?

Yes, you'll likely need longer shafts if you move the axles.

The only way to tell is to measure on your particular truck. Like measuring for shocks, you'll want to measure it with the axle stuffed up (compressed) and stretched out (drooped). Also note that since your front pumpkin is offset, so you'll want to cycle it on that side.

Anyway, with that information you can then decide if your existing yoke has enough range, in which case you just have the driveline retubed for the right length. (If not, you get into more custom/complicated stuff.) I don't see any reason to arbitrarily replacing components that aren't worn; if the shop that installed the lift didn't correct for pinion angles, then you might need to shim either or both ends to keep from eating U-joints ... but the driveline proper shouldn't wear out from that.

Definitely wait until your suspension is set in stone before doing the drivelines.

-- A

 

[496truck]

You're gonna need one of these...

 

[vindemiate]

Is that the double cardan U-joint? That would make up for the driveshaft pinion angle but I would still need to lengthen the shaft. Correct? Though the size of that piece looks like it would tak up more of the length which means I may even have to shorten the shaft.
I guess I better look into the price of those as well.

 

[496truck]

You also need to point the pinion pretty much straight up to the t-case for that to work vibration free. I had that made with a slip yoke cause I couldn't do the SYE at the time.

Talk to your driveline shop, but you have options as far as what they can build.