Wicked steering wheel shake, straight axle, found some issues with my setup...

Little update 8/13/12 :

Car was picked up today, right away he told me what was wrong and will be removing the " aluminum block, flipping the axle and setting proper caster...

We briefly talked about caster, he gave me some insite and mentioned 5-6 degrees is typical for the race car chassis he builds for top end the car forces itself to drive straight....

Shocks will be mounted straight up and down, reading the instructions from speedway they recommend straight up and down or a maximum tilt to the back of 5 degrees. I'll stick with what straight up and down

Speaking of caster, what value or determination goes into figuring out caster on a straight axle ?

I will also be getting full 3" stainless exhaust on the car including ( 2 ) cutouts for when I want to make some noise....

Whats nice is that I'm 100% worry free of this shops work, he was just featured on a Twin Turbo Mach 1 build that flat out shows his quality and I think just pure Love for cars...

Thanks so much guys...

 

Mounting shocks up and down, I have room to either place the shock on the Front, Top or Back of the axle...

Any rhyme or reason for any of the three location options ?

 

No rhyme to it, furthest outboard, and closest to the centre of the spring length (in your case straight over it) would be best. the further you lean a shock off vertical, the less stroke it has for a corresponding amount of wheel travel, and the less effective it is at controlling rebound. keep that in mind. I'm glad you have found someone to fix it, and learnt something in the process!

 

Here's an article on straight axles.
http://www.streetrodderweb.com/tech/0902sr_science_of_straight_axles/

Look at your LF wheel from the side. The bottom of the kingpin should be further forward than the top. It should 'lean back' 5-7 degrees. You can check this using a bubble angle finder against the axle end. It's explained in the article.

And I gotta thank you for
1. coming on here and asking, rather than being a hazard to yourself and others.
2. Sharing the problem and taking the advice. I cautioned a guy on another forum about blocks on a front axle and got told off.

 

Hell thank you......

I hope that this thread will help others, in the process of doing all of this I have learned a ton. Even tho I'm not doing the fabrication I'm grasping a ton of it now....

Speaking of 5-7 degrees, I know that is not much on any angle finder as I was messing around with it just checking random camber points and caster, from how you described going about it it was allot more then 5-7, and that is just a visual check....

All in all, the parts I have on the Nova are ALL quality, just installed wrong, thankfully the death wobble got me thinking and on the HAMB....

Once its all done I'll be updating it....

 

Clocks Off Racing Picked it up Monday and is working on it today Wednesday

He also mentioned the spindles were correct once he flipped the axle but my Thrust Bushing was not right, had to place it to the bottom for the load.

I'm not sure what he means by thrust bushing....

Pretty Welds, just sent me the picture around lunch time

 

Take a look at this picture:



Notice the silver "bushing" under the axle and above the lower spindle king pin boss, that's the thrust bearing.

 

I'm a picture type of guy, could never read book unless there were pictures

I see the bushing and understand, and I would have never known about that bushing, thank god I'm not doing the fab work...

I will guess the Thrust Bushing is a high stress bearing of some sort that allows smooth back and forth motion, but can also take the stress of the road and bumps...

Thank you !

 

Think about all the weight of the front of the car on that axle.
Now, think of the wheel/tire/hub as a jackstand under the spindle sticking out.
All that weight is going from the axle through that bearing into the bottom of the spindle. The top of the spindle is just going along for the ride, keeping things straight.

 

That looks better, pitman arm, shocks, blocks & mounts were scary.. The caster in post #66 looks OK.

 

your a picture type of guy! haha ........well we did go to the same high school......if you need that thing hauled again somewhere let me know the truck will be free again this weekend

 

^ Haha so true ^

Joe I will let ya know

So far so good

 

I got her back tonight !!!

Tires looked I---I like they should, drag link is parallel to the axle, shocks are mounted up and down and full stainless 3" exhaust to 2 magnaflo mufflers. Sounds really nice, not raspy like a pick up truck just a nice deep tone...

Took it around the block and a 15mins drive and its like a whole new car, steering is tight on center, when doing a U turn the wheel natrually spins back unlike before.

Ride is even better due to the shocks being up and down location, for a straight axle car it ride 20x better then I would have guessed...

The true test tomorrow is going on Rawson st, the road is Shit and I'll be sure to try and mimic the speed and lane when I had that nasty wheel Slap...

I will post pictures in a day or two, this stainless exhaust is sweet, welds are perfect !!!

 

shits weak

 

Well I drove the hell out of it yesterday, did some burnouts hit some nasty streets and it rides Awesome !!!

Caster was set to 6 degrees, shocks are up and down, drag link is parallel now that the 2" blocks are removed....

 

Very good information on this thread! I found it on a SEARCH, Dick Spadaro is truly an asset to the HAMB. A good running front end makes all the differance on a gasser style car.

Thanks for the update after all your repairs, good follow through!

 

I know this is an old thread but i only found it today and first thing i noticed was your front shock angle, they ain't doing diddly squat i'm afraid, mount them upright and you will se a vast difference HTH

 

There is a reason "WE" should always read the whole thread before posting on it on any thread When you get to page three or four you find out that he was somewhat ahead of you. But if a guy hasn't been guilty of that he will be sooner or later