pinion angle with cv shaft

[bp71k5]

I just added a 4" lift to my 71 k5. The front drive shaft looks to be a bit short now so I may have to get a longer one. But that's not the big problem. It's a double cardan style shaft so I think the angle out of the x-case is ok, but I'm confused about the angle at the front diff.

I attached a little picture of what the posts say it should look like (A) and the lower one (B) is more like mine. I've probably got ~ 10 degree of angle at the housing. So if I really need to get it to be 0 degrees, are shims safe on the front end to make the angle? Are there any other options?

 

[mofugly13]

Unless you have full time 4wd, I don't think the front angle needs to be worried about, with only 4" of lift. You will only be spinning that driveshaft in 4wd, so unless there is binding, you shouldn't have to worry about it. I have 4" springs (+D60 with taller spring perches= ~6" lift) on my K5 and if I engage the front axle, or just the front hubs, I can feel some vibe at highway speeds, but I have learned not to do that.

 

[bp71k5]

Hmm. Ok, sounds like i just need to try it out and go from there. Thanks.

 

[4X4HIGH]

The drawing you have (A) is correct for a rear CV shaft. The front shaft you don't care too much about the angle on the shaft as you do about the caster angle. The front shaft is obviously only spinning under power when in 4WD which is at slow speeds and won't matter on the angle so long as the shaft isn't binding.

 

[bp71k5]

Hmm, I didn't think about the caster angle. (I'm not even sure what it is). Before I dropped springs, it did sometimes make some really loud "cluncking" noise when I was in 4wd and backing up. The steering was also pretty loose so I'm rebuilding the whole front steering/suspension to try and figure out what's the matter. I think I"m good on the back because it looks like someone already rotated the axle tube to make the pinion angle 0, but the angle out of the x-case in the rear is the same as the front and I don't have a double cardan back there.

That's cool to see some bay area people on here. I'm just down the road in san jose, but I'm getting lots of my parts from a guy in Fremont.

Thanks

 

[4X4HIGH]

Who are you getting your parts from? If it's a shop my guess is Vintage Chevy Trucks. Anyhow, if you don't have a CV shaft in the rear then both the front and rear working angles on the driveshaft need to be the same or you will get a vibe and prematurely wear out the U-joints. If you ever need any help just PM me and we can get together.

 

[bp71k5]

Yep, I got my steering box from him to do the crossover steering conversion. I'm trying to put together a solid drivetrain so a new double shaft on the rear sounds like my best bet. It's like they rotated the rear end to allow for a double shaft, but put the shaft on the front instead. Any recommendations for a new shaft locally?