question about welding leaf spring pads on axle

I picked up a montecarlo rear end and wish to use it with leaf springs instead of the factor coil springs and bars.

I purchased leaf spring pads and am looking to weld them on the axle after removing the previous coil mounts.

In which orientation do i put the pads on the axle exactly so that i dont have to much trouble when i come to set the pinion angle

do i just set the carb level .and then set the pinion angle to the same angle as the engine angle and weld the leaf pads onto the axle

and adjust pinion angle later by means of wedges

 

set pinion angle first then weld, otherwise your gonna have probs!!

 

I did a bit of googling and post searching and am a wee bit confused about when people talk about offsetting the rear.. should the two angles i'm measuring for with the angle finder be the same?? that is the pinion angle and the angle formed by the centerline of the ****** shaft and that of the driveshaft

 

ditto

I wouldnt weld the pads on until you have everything bolted together in the rear. Driveshaft, tires, leaf springs etc. Leave the ubolts on the leafs a tad loose so you can twist the rear end until you get the pinion angle where you want it. Make sense?

 

Level the frame, center the rear in the body, put jacks under the springs so you are "really" simulating how it's going to sit, set the pinion to 3* up, tack in, remove and weld fully.

 

Read above advice, measure more than twice.

 

Listen to the guys above Car level Check angle at trans do the opposite on rear and tack weld leaf pads in place.
Once your sure your degreed in weld Carb level depending on intake angle.

 

Wait 'till the cars done, and all your weight is in place.

Also, on a leaf spring rear end, you should angle the rear end DOWN a degree or 2 from the correct angle, so that when you get on the gas, and the springs flex a bit, she'll be in the right place, as the pinion will flex UP when under torque. If you match them at rest, you'll be off by a few degrees under load.

Good luck,
Pete

 

Thank you

 

Hey guys I just bought a good sears protractor and also a good streetrodding book ***le Tips and Techniques looks like a good book.


witht the car level the face of the ****** seal is 3 degrees below horizontal and just out of curriosity the shaft face on the rearend that is on the car now was read at 6 degrees

 

shouldn't the trans shaft and the input shaft in the diff be parrallel and forget about how many degrees up or down?Set your engine up first and tack your spring pads in place.I did this and had to move them after everthing was mocked up.

 

I am not sure if this was answered, mentioned, earlier, but you do not want the flanges in line with each other. I set driveshaft alignment three degrees offset at each of the flanges. Six degrees total. Three up...three down. In line will very likely cause vibrations. I'm sure others will jump in with more. Lotsa knowledge here!!

 

Center line of transmission and center line of rear axle need to be the same....

 

under load not static, the leafs will wrap slightly when under load, 3-4 degrees down from crankshaft centerline is about perfect.

 

I sure wouldn't want you to build my rear set up. Pinion angle need to be set "DOWN" not up. Up angle with leafs wouldnt hook up on a nail board. A 2-3.5 down angle would be just fine and have the ability to hook up under hard launches.

 

Here's a good article from the Jeep and 4x4 world (another p***ion of mine). A lot of it may not apply to hotrods, so some of it may be information overload, but Part 1 and Part 2 have a very good definition area and description of driveshaft geometry.

http://www.pirate4x4.com/tech/billavista/PR-shaft/index2.html

Good luck,
Pete

 

from crankshaft centerline. if the tailshaft of trans is pointed down say 5 degrees, the pinion should point up 2 degrees.

 

Leave it loose until everything is mocked up.

 

Hi 32 chevy. U gettin there.
Don't worry about welding the pads in till you have everything in. All the weight etc.
If u must just tck in so u can run it around the yard, When all is set. Tack it good then pull it out flip it and wekld away as said previuos.
FYI mine is now on the road.

Not from what I've read
Centerlines need to be parellel. You may have an offset pinion !

You do not want the shafts to be lookin at each other. Vibration.
3 degrees as everyone seems to agree should work. One up ,one down. Cancel each other out.
I've been told engine or oinion offset left or right does not come into play as long as the centerlines are parellel.

 

Yep well i figure out what i needed to. I prepped the axle for the pads just waiting on speedway to send them out. In the meanwhile I 've been laying line and plumbing away

 

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Hmmm, building by committee.

 

Lots of bad info here

 

Google Inland Empire Driveline. Their website explains it very well with diagrams...just the way I was taught 40 years ago. It works.

Charlie

 

Quote:
Originally Posted by chopolds
Level the frame, center the rear in the body, put jacks under the springs so you are "really" simulating how it's going to sit, set the pinion to 3* up, tack in, remove and weld fully.

That article from Inland Empire Driveline was very good!
This quote from the article on setting up driveline angles:

"Engines are set in the frames at 3 degrees downward angle to the rear. This is virtually a world standard for engine placement is the basis for intake manifold construction. It is this fixed installation that determines the possible. To arrive at equal and opposite U joint angles the pinion must be set at parallel to the crankshaft."

So, if engines are set up at 3 degrees down, you need for the pinion to be at 3 degrees UP to have it parallel with the crankshaft. I rest my case.

 

Yeah, lots of opinions. I've always followed the advice here and so far so good.
http://www.4xshaft.com/index.html
Click on tech info in the upper right corner, then geometry 101.

 

Bear in mind that u joints do NOT like being straight as they do not grease themselves if straight. U joints are made to operate from 3-7 degrees in the "Normal" range (included angle).

Having said that, if the trans is -3 deg. then the driveshaft angle can be as little as -6 and as much as -10 deg from horizonal. then you can rotate the rear axle to be in the 7 degree (included angle) range as long as you have the -3 or -3 at***ude. sounds complicated, but it is not. MIZ

 

I agree with you...BUT why not set up the car for the "almost" perfect angular condition while siting still, at rest?
The act of driving the car will automatically put the U joints into other angles, as you go over bumps and dips in the road. So setting it up right (hopefully) in the middle range of it's motion seems like the right thing to do!

 

I sure wouldnt want you building mine either

 

Wow lots of differing opinions here - the Inland Empire Driveline piece is a good place to start with proper advise.