1956 S-102 Build

Just as you were posting I was going to pose the question of what was the original angle. My first thought was that we need to give IHC some credit and assume they knew something about optimizing the pinion angle. So with the perch horizontal, what is your final angle then, 96.8 or 83.2?

If the basics details are adhered to under the static conditions of construction, then the dynamic changes of movement in the suspension will be absorbed by the built in geometry of the system. That's why there are spring shackles at the rear of the leaf springs, splined slip sections either at the yoke of the transmission or built into the drive shaft, and u-joints. Movement has to be absorbed effectively and all of the components are designed to work in harmony with each other. Proven concepts are there based on the research that went into developing them. Some of that research is based on trial and error, but most of the trial and error is past and the basic concepts rule. By all means, if the experts are saying check it at ride height, sounds good. However, 6.80 degrees seems a bit steep if others are saying the pinion angle needs to be 1 to 3 degrees.

COPY AND PASTE:
The spring is fixed in location at the front, but moves back and up with the shackle at the rear.
This statement leaves the impression that someone has eliminated the shackles on the front axle springs. This is a very bad situation. The spring shackles should be on the end of the spring where the OEM put them. The shackle location will make the spring react to compression properly and better keep the pinion angle.
I thin this subject is being way over talked about. There is only one way to get this correct and that link has been posted. Any guessing is just that, a guess, and should not be taken as a working guide. The problem with posting a guess is someone may take it as short-cut to success and build in a problem. A guess could say the poster does not understand and should read the instructions again.
I often visit another forum on workshop and machine shop stuff. That forum requires every poste to be backed up with fact.
Here is "the thing". This is a truck and in its previous life, it is reasonable to assume, the truck was driven empty and probably ran over-loaded on a fully compressed suspension more than a few times. While cab and box on or off could make a very minor difference in matching pinion angles it may be less important.
http://www.hotrodhotline.com/md/html/dr ... monics.php
If anyone needs more convincing than this, Inland Empire Driveline out of California have a bunch of teachable moments in downloadable PDFs on their website. Google it.

I was referring to the rear leaf springs only. They are at a fixed point in front, and move with the shackle at the back. Sorry if that led to confusion.

Paul, No confusion here I knew what you were talking about. Yes, all four springs are fixed at the front and move at the rear. This is why I am waiting until the cab and box are mounted for the ride height before I set the rear pinion angle.

When a leaf spring compresses, the rear eye does not go up or down much, it goes rearward because as the spring is compressed it grows in length and the shackles swing more rearward than up or down. It is in the design of the leaf spring to hold the pinion angle true. The most the angle will change is under hard acceleration, then the spring will wrap up slightly but will return to it normal position in a very short time.
No offense to anyone, but measuring the perch angle on or off the vehicle does nothing, the important thing is the pinion angle when installed at ride height. Measuring the perch angle when it is setting on the floor does not mean anything.
Bill

Ok then, On with my build topic.

Took a little time Sunday after making a pair of tire chains for the newer truck to install the rebuilt/converted 12 volt starter on the IH. I had this starter converted to 12 volt and changed the solenoid to 12 volt about 3 years ago but I re-cleaned it and painted it a little better than the rebuilder did. I still need to buy a brush cover for it that actually fits, I have a few leads just haven't bought it yet. The chrome cover that the rebuilder installed on it was too big and instead of installing the correct size they opted to wrap the starter under the cover with "masking tape". Very professional I have to say. It does work, I have tried it on the engine before I took the engine out to paint it but after seeing the masking tape you have to wonder what was done on the inside of the starter...

I wouldn't get too concerned with the masking tape. I've come across that on a couple of starters and generators, even with the correct cover bands. I think it probably adds a little more protection against dirt infiltration.

Kris,did you get my PM with the pn etc. for the cover you need for the starter? I didn't get a reply and don't even know if it went thru.