'36 Chevy Sedan "The PackRat Rod"

[RimSpoke]

Thanks Animal... maybe we will I've been out your way a couple of times.

Somewhere along the way I got the bright idea that I could mount the spring behind the axle instead of on top of it as I originally planned. Here's a shot of all the pieces (both purchased and fab'd) that I planned to use:

The DOM tubing's .281″ wall [center under spring] gives me an I.D. of 11/16″ which is the same O.D. as my 9/16″ I.D. bronze bushings [center front alongside the wet bolts].


After (hopefully) many years of wear, the bronze bushings will be able to be pressed out and replaced, saving the actual mount from any wear.

The down side to changing plans mid-way through was not only a lack of sufficient suspension-travel clearance between my bracket and the frame, but what's not shown is that after installation my crossmember is sitting smack on the tie-rod.

I sat and stared at it for a half+ hour or more and could have gone down a "change this, change that" road, but I went back to my original plan instead.

 

[RimSpoke]

I cut the spring mount off the base plate and started over:

The angled mount should allow enough room for the spring to flex without driving itself into the bracket or the base. If I find it does otherwise, I'll be cutting it back apart and raising the bracket some.

Once I was satisfied with fit and clearances, I pulled the pieces apart and welded everything solid.

 

[animal]

Lookin' good! I know what it's like to change, not dig it, and change back. I built a whole bunch of choppers from the ground up.

 

[MercuryMac]

Whoa, RimSpoke , you just wrote the text book on 'changeover from parallel spring axle to transverse spring'. I'll be steal----- using your ideas on one of my open wheel hotrods. Thank you.
Always a pleasure reading your stuff.
Keep on tinkering.

 

[RimSpoke]

Thanks loads!

... and since it's just us guys talking, you might as well know the original plan was to go quarter-elliptical:

The spring is shown here clamped to the outside of the framerail just to check the look. The plan was to widen the rail and have the spring poking out from the front ala chopper / old rail-job. I really like the look of an old altered.

I actually widened the frame horns and had the spring inside before pulling the axle back to under the grill shell and switching to transverse.

What a bear to cut through spring steel! I still have the spring packs and intend to use them on the next one. ' can't help but keep looking at zpi28's

Anyway, back to the build...

 

[05snopro440]

That's going to be a sick looking car!

 

[Dirtyrat]

Loving the QE look... wish you were keeping it!

 

[RimSpoke]

Me too!
About half-way through the decision was made to give this one to my brother. Mine (next) will most likely be fully stretched with the 1/4 elliptical springs.

' appreciate your input.

 

[christcrusader13]

I love what you have done with the front, thanks for all the detailed pictures!!!

 

[RimSpoke]

 

[jfg455]

That motor makes me all giggly inside! [P

 

[sgtpontiac]

Giggly????

That motor makes me all giggly inside! [P

WTH??!! I'd say .....Happy....even maybe.....Tingly.....but Giggly?? Been knawing on some of them there cream donuts with the sprinkly thingies on them jfg??lol

 

[RimSpoke]

I got the engine and bellhousing on their mounts last night.

Today I bolted the transmission to the bellhousing to get an angle off the output shaft. (I don't have the clutch, pressure plate, etc back in yet. I just wanted to get it sitting right for the angle measurement.)

Tomorrow I should be able to transfer that angle to the rear pinion and weld the spring perches back on. Then I can measure for a driveshaft.

 

[RimSpoke]

Well... today didn't work out as planned. I figured I'd get the front off the jacks and stabilized before moving the rear around but some unrelated stuff popped-in.

The front axle is bolted in. I'm just waiting on the ball-joints to finish the radius rods.

(I refrain from calling them "hairpins" because the top bar on mine is straight and the lower will curve down from it. A real hairpin looks like a hairpin with both rods bending to the ball joint in the rear. Just one of my many idiosyncrasies. No offense is taken either way. Smoke if you got 'em.)​

Somehow it's the tilt of the camera that makes the frame look so tweaked. Look through previous images if you want to see that it isn't... or just wait for more. I'm sure I'll have some.

I don't know why I painted the spindle separate from the drum. It's going to be under that small round hubcap. I guess it's underwear that's fun to wear.

And this is where I thought I'd be by lunch. Oh well. It's progress none the less. Good thing I'm off tomorrow. Maybe I'll be able to get those pesky spring perches welded.

Stay tooned.

 

[1952B3b23]

Progress is always good, how many degrees do you have the motor/trans angle back at, just curious?

-Chris

 

[RimSpoke]

Chris,

My concern wasn't so much about what the transmission output shaft angle was going to be as much as it was that the engine sat level with the frame at ride stance:

On a fuel injected engine you can pretty much do what you want, but on a carbureted engine it's important that the carb sits level when all is said and done so the floats work as designed.

Please note that you can’t always rely on leveling the engine block. Many times V-8 intake manifolds have a forward slanted carburetor mounting surface... but the intake on this inline 6 runs in the same plane as the deck. I checked long before removing the head. ​

After getting the engine where I wanted it, I put an angle finder on the transmission output shaft and saw that it’s just a degree shy of vertical. You can use one and switch back and forth but since I have two I put the other one on the rear pinion and blocked the rear up until it was sitting at the equally opposite angle.

If your transmission is pointing down one degree, you want the rear pointing up equally just the one degree. If the trans output is at 3, the rear needs to be at 3. Many people make the mistake of pointing the rear directly at the transmission output and are then confused when the thing vibrates beyond belief.

Attach both ends of the driveshaft to their respective mounts and you’ll find they’ll travel through their limited range without binding only if they are able to maintain angles that are equal to the shaft centerline simultaneously. We refer to this as being “in phase” and is what minimizes vibration and prevents the binding created by an out-of-phase angle trying to rotate on its own centerline ripping your u-joint apart.

If you’ve ever put a universal-joint on your socket wrench extension and then leaned it at a bad angle while spinning, you’ve felt it bind. Imagine this with a 1:1 trans output ratio or even .9:1 and an engine turning 2500 rpm or more. Something will give.​

With that done, I tacked the spring pads back onto the axle tube.

 

[RimSpoke]

The rear of the frame is still up on the jack but the wooden blocks are no longer needed under the differential. It’s pointing
in the right direction on its own. I’ll pull the whole assembly out on my next set of days off to finish welding the perches before
bolting it back where it belongs.

The front is all bolted-up to the spring and supporting its own weight.

I’ve got all the necessary pieces to finish the radius rods but have to get a tap to thread the ball-joint end. I just wanted
to make sure I had the right hardware in-house before cutting into the tubes.

 

[Old Iron]

I’ll pull the whole assembly out on my next set of days off to finish welding the perches before
bolting it back where it belongs.

Lookin good RS !!!!!!!!!!
Before welding the spring perches, did you take into consideration the pinion angle will change a lot, when the weight of the body and all the interior is put on the suspension?
Just don't want you to have to re-due anything
Ask me how I know

 

[1952B3b23]

I have heard of the same thing happening as what "Old Iron" describes. When you add the rest of the weight of the car the pinion angle will change. Im pretty sure they make shims that you can added between the leaf spring perch and leaf spring to correct the angle. Good luck and the build is looking great! [cl

-Chris

 

[RimSpoke]

I suspect it will change every time I hit a bump and compress the suspension. I'm obviously at full travel now. With some weight it will be somewhere at mid-travel. With a lot of weight it will be at no travel.

I'm no corporate engineer, but as the pinion angle changes so will its position relative to the transmission as it swings through the arc created by the front mounting bolt. Email and message boards are rough on communication sometimes but I think you're suggesting that it would've been better for me to set my angle while the vehicle was at mid travel. No argument here if that's the idea as doing so would give me a + or - change on either side of center. I just don't know that it changes the math any. It needs to be in phase as the angle changes with position. As the rear comes up, the angle decreases through the swing.

What I didn't like was not seeing much compression during the many times I've taken the body on and off these multiple times. My concern with that is that it's going to be too stiff and ride like a rock. If that's the case, I'll need lighter springs. It's probably going to be too "jacked-up" in the rear for my liking as well and that will necessitate less spring arch which we all know will affect this.

No shims for me. If this doesn't work as intended, I'll cut the pads again and make it right. Thanks for the input & shared experience... sincerely. You're making me think even more about it and I appreciate that.

I think it's going to work but am old enough that I usually leave room for the possibility that I could be wrong.