Pitman arm/ cowl steering woes/questions

"haha. its all cool, yeah ill get the tires rebalanced, and check eveyrthing else out, dad owns a shop that can do all this, has an alignment setup, etc."

Speaking of smart ass replies....1600+ posts and doesn't know what caster,camber,toe in-out means a little smart ass might be what he needs to retain somethin'. Geezus,Louizus!
Where did that humongous tool box come from?Oh and why do ya need it?Ya got Dad?
Really clean well lit garage though .LMAO

 

Yo Baby...you should see his striping! His talent is in the brush.
Clark

 

Dick...I did not know there was a difference in the angle. Thanks
Clark

 

I can dig it Clark.I can't do a thing with a brush,not a striping brush anyway.
But gimmee a hammer and I can fix anything.LOL

 

I suck with a brush too!
Clark

 

One other thing to think about here that no one mentioned. Is that steering box braced and structurally sound? With the car sitting there and when you turn the steering wheel really hard back and forth does anything flex at all. You may need help seeing this with a friend. Just a thought. All these things go into play in some way. Answer Dick's questions and he may be able to direct you to the source of your woes. I used a So-Cal steering dampner to solve my bumpsteer. They work good.

 

there was a post a few days ago about this:

http://www.jalopyjournal.com/forum/showthread.php?t=60986

 

I am going to give a try with a longer pitman arm before i go redesigning the entire steering setup.

and yes i KNOW i am going to have to check caster, etc. etc. but thats not what this post was supposed to be about.


oh yeah and Yo Baby, go fuck yourself. with a big black dildo.

 

answers above. thanks for the input, its really appreciated. like I keep saying its not bad, and i overexaggerated the "death wobble" hell i drove the car from albany, NY to new brunswick, NJ at stop and go 65mph highway speeds. i think if anything its just a minor bump steer problem and maybe a LITTLE LITTLE wobble at about 20 mph.

im going to get the tires balanced, check the tire pressure and try a longer pitman arm.

it will be damn near impossible to relocate the box without extensive modification and loss of feets!

 

Nowhere in all this discussion is there any mention of what might fit the old Pontiac pitman shaft. (I PM'd you on your ad in the classifieds) Your chances of finding a long arm are best if you're looking at aluminum sprint car arms but even one of those isn't going to do you any good if the the splines don't match. If you should happen to find one that works (fits precisely) there isn't any concern about aluminum since the arm fits tight and the big nut holds it on-there's no relative movement between the pitman shaft and the pitman arm.

 

reason i didnt ask that is because i have one that fits but it is bent/tweaked a little, i seee the same one i have on ebay right not thats not tweaked.

the splines match up.

i also can get my one i have on there now extended or get one made up.

 

Can I ask you what book you got this from? What angle do you have for the A-36 axle? My 1948 Motors manual (no it's not a Ford manual) lists the KPI for all the the years from 35-48 as 8 degrees. I have a set of 35-36 spindles. When compared to the 48's they angle looks identical. (I can hear all the machinists groaning) I was going to set up a comparison with an angle finder between the 2 but I never got to it. If there is a difference it should be measurable. It seems to me if there was that much of an angle difference, the tires would be leaning throwing the camber way off. Right?

Don't take this personally. We've both been doing this for a long time. You are the only one that has ever said this. I'm not too old to learn.

 

FOLLOWUP TO POST:

1. Since you are indicating that you have some difficulty with steering return that can probably be traced to the incompatiblity of the spindles and axle. Until you exchange parts you will have to live with it. Assuming the caster has been set at 6-8*, changing that will not help steering return.

2. I may have been a bit clearer on the steering rotation if I had equated the steering experience to you normal every day driver. Your HR should turn similar to your every day, is it slower or faster? If it is either there are 3 places to look pitman arm length, steering arm length and tie rod arm length. Steering input should be similar to your driver.

3. 3 & 4 are a combined question to isolate potential problems. Since you are experiencing a slight bumpsteer. The angle of the front shackles should be addressed. Shackle angle should be between 20-40* and there should be no slop in the bushings. As the shackle angle exceeds 45* the opposite side canceling angle is eliminated and the front suspension begins to act like a swing within the frame and darts right or left because it is not located, necessitating a panard rod installation. In addition the high angle of the drag link may promote some steering movement but you realize this already.

5. you are already addressing that.

6. DO NOT purchase used race car pitman arms from ebay, I have first hand experience of stripped splines in aluminum pitman arms from crashing. A trip to your local race shop will give you a selection of different length pitman arms, just make sure that the spline count and taper is the same. Price should be less that $60.

Good luck on your project.

 

Yeah, I do get this quite alot. Until I was diagnosing a steering problem I did't realize the effect either. Most Motors manuals have information from 1935 and up that states the KPI is to be 8*for 36 and up spindles. Now if you start researching the Ford Service bulletins you will see that the earlier spindles have a KPI index of 7*, T's 0*. It is hard to believe that 1 degree has an effect but it seems to be very evident when swaping late spindles on stock early axles. It produces very hard steering and makes steering return very slow or needing a manual assist. Now for some reason this is not so prononced with homemade dropped axles. I think that since most dropped axles are streched, this has a tendency to tip the king pin axle boss more and the increased camber angle and hides the difference.

I have a Bear alignment education book from 30's that is excellent in explaining front end dynamics. I have used it thru college and for reference today. The hardest part is understanding the principles of camber vs kpi and the dynamics when a spinning wheel is in motion. Hope this answers your question. Dick

 

"6. DO NOT purchase used race car pitman arms from ebay, I have first hand experience of stripped splines in aluminum pitman arms from crashing. A trip to your local race shop will give you a selection of different length pitman arms, just make sure that the spline count and taper is the same. Price should be less that $60."

I've never seen a sprint car or midget pitman arm with a tapered spline. The ones I've owned over the years have all been straight. Most are 1 1/8" dia. and a few, like some midget gears, are 1". In any case, an aluminum pitman arm ain't my first choice for street use.

 

Dick Spadaro,
what are your thoughts on using an after market dropped axle with post '36 spindles, or thoughts in general of after market axles versus stock axles? Shall we assume that Superbell, magnum, Chassis Engineering, have done their axles the proper way and that they are set for the later KPI?

I don't have any real practical experience with any of this. I do follow these discussions pretty closely and it seems to make sense to me. I'd like to hear your opinions, you definately seem to know what you're talking about.

Woody

 

Caffeine, what came of all this? Been doing some research on cowl steering topics and would like to know what you ended up doing?

 

I just balanced the front tires, they were off 275 on outer on 1 and 175 on the inside...then they did the them again, and had to put another 25 on the opposite, etc. both wheels were pretty much like that. taking it out for a long drive tonigth so ill let you know.

 

Porknbeaner, Do What Ever You Have To Do To Get The
Drag Link Level From The Pitman Arm To The Left Steering
Arm. Kpi Stands For King Pin Inclination. Maybe You Could
Raise The Business End Of The Steering Arm, Lengthen The
Pitman Arm, Or Maybe Lower The Steering Gear, With The
Main Goal Of Getting The Draglink Almost Level, Or
Running Downhill Only Slightly. Good Luck.