driveline angle?

I've read that the driveline angle should be 3 degrees. I have a Ford 302, if I put it in the frame with the intake level will this give me the proper angle? Also when setting up the rearend should I set the angle of the pinion then install my brackets so that the angle is set or use the adjustment on my 4 bars afterwards? Am using a triangulated 4 bar with Jag coilovers. Coilovers will have the mounting bolts parallel to the axles.

angle

l use a magnet angle finder l got at harbor frieght, it sits on the shaft and works great.

measure at where the rear u- joint attatchs to rear-end.

when l did mine, l measured with the weight on the axle to get an accurate reading. you can put the axle in the rear on jack-stands and on the front frame rails.


l had to make shims for the rear leaf spring pads for the rear-end to sit on.
l used 3'' wide X 1 1/2 tall bar stock aluminum and milled it at an angle to get the 3% up angle at the rear u-joint. no one had what l needed to make the dodge truck sit correct when on the ground.

with the four-link it'll make it easier get the 3% up angle, just remember, the weight has to as if it's on the ground and at ride height.

hope this helps,

Later

3 degrees down at the transmission tailshaft, 3 degrees up at the pinion. Set the pinion angle first, then install your brackets.

thanks you

Blue Eyed Devil said:

3 degrees down at the transmission tailshaft, 3 degrees up at the pinion. Set the pinion angle first, then install your brackets.

Click to expand...

thanks l forgot that part mr.Blue Eyed Devil.

l am so used to doing this over the years, l forgot not everyone knows that up/down thing.

Later

I shoot for 3 up on the pinion and 3 down on the tailshaft, like the others have said, but rarely have I been able to lay a level on the intake and have it sitting perfectly flat. It seems most aftermarket intakes have the carb mounting surfaces somewhat leaning forward, so the tailshaft would have to be way down to make the carb absolutely level. But it doesn't seem to matter. They still run fine like that.

Don

It doesn't really matter what the angle actually is, but the rule for Universal Joints is that they must be the same angle, ie: flange faces must parallel.

Or, they can be opposite, such as if the front is facing 4 degrees down, the rear can be too, as long as they are both the same angle, which is the polar opposite of what conventional wisdom states, except it is true.

That is the way U/J's work. Think about it.

It seems when pinion angle is discussed it always turns into a debate. I mostly agree with whats above but there are variables. For instance what if you're running leaf springs in the rear, that would also affect angle? I'm curious to know what the above think about that. BTW didn't mean to hyjack your thread!!!

had to deal with pinion angle after the axle flip

Had the spring perch's off anyway but still proved to be a task to get it where it needed to be so I could weld the perch's back on.... got it done and it's about 3 degrees neg so it is about 1 degree more than the trans yoke... looks fine with the trans angle and shaft angle......... so I'm happy....

Most conventional engines are manufactured that when the carb is level then the engine has a negative 3 degree tilt.

there are about as many opinions on this as on politics

EnglishBob said:

Most conventional engines are manufactured that when the carb is level then the engine has a negative 3 degree tilt.

Click to expand...

Ask 10 people what the pinion angle should be and you'll get 10 different answers..... race and street are not the same so many avenues to travel here....JMHO

my delima

rainman said:

It seems when pinion angle is discussed it always turns into a debate. I mostly agree with whats above but there are variables. For instance what if you're running leaf springs in the rear, that would also affect angle? I'm curious to know what the above think about that. BTW didn't mean to hyjack your thread!!!

Click to expand...

when l sub-framed the 1950 dodge truck, l used 1977 nova and left what the previous owner used in the rear. it was a 8 3/4 on under the rear leafs and it left me a 9% up angle on my drive-shaft.

changed the rear-end to 12 bolt 3:36 posi outta 1973 camaro, set the
rear-end on top of the leaf springs and it had a 5% up angle.

l had to make shims for the rear leaf spring pads for the rear-end to sit on.
l used 3'' wide X 1 1/2 tall bar stock aluminum and milled it like a wedge to get the 3% up angle at the rear u-joint. no one had what l needed to make the dodge truck sit correct when on the ground.

Later

if you watch the pinion cups as they rotate around the center of the spinning shaft...
if the driveline is straight without any angles the pinion cups rotate in circles around the center of the U-joint and driveshaft.
If the driveline is angles, the pinion cups travel in eliptic orbits around the center of the driveshaft.
You might think that's impossible, the u-joint is solid and the pinion cups cannot move closer to or farther from the center of the driveshaft.

when you bend the driveline at an angle the U-joint and driveshaft are not spinning at the same angle and because of the angle...when one pinion cup is nearer the driveshaft...the other is farther away and it changes the angle that the pinion cup is turning the driveshaft...the driveshaft speeds up and slows down every 90 degrees because of this effect but since the other u-joint on the other end is doing the same thing...it cancels out 100% and you never feel it.

the reason for designing in some angle is so the needle bearings in the pinion cup don't sit in the same place all the time and get out of round.

If they sat in the same place all the time it would wear funny just like roller bearing kingpins on older 4x4 front axles before they went to balljoints.

Pinion angles

How about getting it straight from people who do it everyday fro a living? The link below is a really good reference with good illustrations and expalnations.

http://www.iedls.com/asp/admin/getFile.asp?RID=10&TID=28&FN=PDF

A really good article you found there CB! This should go in a Tech bin on here somewhere.

I thought I was pretty well versed on driveline but I got a few extra pieces reading it.

Thanks,
Paul

driveline article

I found it while trying to solve the same problem on a build of my own. I hope it helps out on the OPs issue.

Larry

The shaft should also never run inline with the trans and pinion. This will cause a vibration as well.

I do 3 deg. both ways