I've got a little 2" square "magic cube" electronic level/angle finder that works great for this, and I typically use the u-joint cap if it protrudes or the yoke around the cap if it doesn't.
Just have to turn driveshaft so the yokes are vertical to check.
Other spots are the machined flat to either side of the cover on some rears.

The pan rail on the trans is not parallel with the shaft centerline of the trans, so don't use it....it is typically cut to be level to the ground when the engine is on the stock3-4 degree angle.

The cube has magnets in two faces. On my list of one of the best things I've bought from Harbor Freight

https://www.harborfreight.com/hand-tools/measuring-marking-layout/digital-angle-gauge-63615.html

 

I've got a little 2" square "magic cube" electronic level/angle finder that works great for this, and I typically use the u-joint cap if it protrudes or the yoke around the cap if it doesn't.
Just have to turn driveshaft so the yokes are vertical to check.
Other spots are the machined flat to either side of the cover on some rears.

The pan rail on the trans is not parallel with the shaft centerline of the trans, so don't use it....it is typically cut to be level to the ground when the engine is on the stock3-4 degree angle.

The cube has magnets in two faces. On my list of one of the best things I've bought from Harbor Freight

https://www.harborfreight.com/hand-tools/measuring-marking-layout/digital-angle-gauge-63615.html

Thanks man, that's just what I needed.
More questions to come for sure. But for now, I'm good!

 

Just thought I'd look real quick, since I didn't remember paying more than about $20 for it 7 years ago....they are available all over Ebay from as low as $9 in several different forms.

It's one of those cheap offshoot technologies from Smart
Phone development, like the GPS speedometer apps.

 

I have a magic cube also. Originally bought for setting birdcage angles on a sprint car. It also works great for driveline angles and a lot of other applications.
For a place to measure, I like to go where the rubber meets the road. I have an extra driveshaft slip yoke. My 13/16" deep well Craftsman socket fits snuggly in the U joint bore. I remove the driveshaft, install the yoke, rotate the socket to vertical and get your trans angle measurement. Then I bolt another 13/16" socket in the pinion yoke for the pinion angle measurement.

 

Thanks, I ordered my Cube the other day. I love these ideas! Truck is actually up on the lift right now getting a new headers and x pipe install. Also putting my dirty dingo Trans crossmember in it too. So now will be a good time to adjust everything out.

 

Remember that this is not a required precise measurement. I t needs accuracy, not precision. I use a cube as well that goes to the tenth of a degree. Anything from 0-+2 degrees of pinion angle will work unless your rear suspension is extremely flimsy.

 

Gonna have Cal-Tracs. Just an old 70s model 1/2 ton truck. So not too flimsy!
Hopefully this baby can plant the tire. 4020 pounds with me in it. Tank is in the back, behind the axle between the rails. Battery is on passenger side where the old tank was. I have plastic splash shields in front that weigh about 24 ounces each. Im going to see how it does. Hopefully I will have enough power to not want to get a bunch of fiberglass parts for the front...
Street cruiser, with the occasional trip to Rockingham.

 

Got my cube, and about to install Cal Tracs today. I'm having trouble with the calculator though... My trans tailshaft is 5.0 down. My Driveshaft is 3.0 down. My pinion angle is 1.5, but I dont know if I should enter it as sloping down, or up... The front is pointing up, but everything I have seen is so unclear of the slope...

Should I calculate the pinion angle as sloping down, or up? The front, where the U Joint goes is pointing up. Also known as the Driven Member.

Here is the calculator I'm using.
https://spicerparts.com/calc/driveline/index.html

 

Generally you want the transmission and pinion center lines on the same plane but not intersecting the tangets.
For example, Trans is down 3', Pinion is up 3'.
If you can move the trans up to 3', and the pinion up to 3' that's ideal but if you can't +/- 2 that'll be acceptable.

 

Ok, so I just installed an adjustable trans mount too the other day when i replaced the X Pipe. It can come down some. That will get me closer. And I think you answered my Question also. I need to input pinion angle as sloping up in this calculator?
And by the way, Get To Work! You wont make any money sitting around answering silly questions all day. But I sure do appreciate your quick response.

 

Were on the Hell Tour so yeah, a lot of roads to come

 

Okay guys, I'm still a little bit confused as pinion angle sloping up, or down?
It is a necessary piece of data for the calculations to come out correctly.
I watched the video from Spicer and I know the transmission is sloping down, I know the drive shaft is sloping down, but it is very unclear where the pinion angle should be input into the calculator as sloping down, or up.
With the truck sitting on the ground and suspension loaded, the front the pinion gear is higher than the rear of it.
Everything in my heart tells me it's pointed up, but I don't understand this drive shaft angle calculator well enough to figure all this out!

 

Your stuck on the word slope(IE angle).
The calculator is stupid. Disregard it.
I recommend the trans pointing down toward the rear of the car 3’ and the pinion pointing up toward the front 3’ and let the driveshaft be where whenever it is cause it doesn’t matter. Don’t even bother measuring it.
Now, drink beer and worry about something else. :thumbup:

 

How did you know I've been day drinkin'?
Thanks for making it simple. Just got her back on the ground after installing the CalTracs. Went for a spin around the block, no more spongy butt. I've been closed all week and getting alot done around here lately! Feels weird...

 

Cause wrenching and cars makes one wanna drink!

 

Moving right along. Just installed new U Joints in my Suburban Aluminum Driveshaft.
Now we are at 3 degrees even, going downhill for the Engine/Trans angle.
I ended up putting the transmission jack under the tranny pan, and letting the truck down on to it. Had to squeeze the last degree out of that joker... Next time I have the tranny out, I will massage the tunnel up with a 3 pounder. I'm sure it left a witness mark! The pinion was sitting right on 2.9. So I figure that is close enough...
I'm about to install my Billet 1350 pinion yoke. The Aluminum Driveshaft out of the Suburban came equipped from the factory with the Big Cap 1330 UJoints. So I reckon those will hold up in my application better than the spaghetti DOM shaft that BIG10 was born with.

Nice and hot out here today!