Front end geometry help needed (new pics added 7/28)

Okay here's the scoop. I've got a '66 F100 thats had a MII style of front end put under it by a PO. Not sure of the manufacture, it does have fatman front springs but as far as the crossmember and upper and lower arms, I'm not sure. Its not a coil over. The problem that I have is the lower arms and tie rods are running uphill at I'd guess about a 7 to 10 degree angle. How can I get these to run level? The tie rods I'm thinking I can either one, raise the rack which would require redoing the mounts or two, using longer tie rod tapered ends and run a spacer below the steering arm like is done on stock stub type race cars to improve geometry. As far as the lower control arms, do I need aftermarket spindles or what? Will running a shorter spring accomplish what I need? Thanks for any and all help.

 

P I C T U R E S - Would really help with this

 

Is the fact that the arms are running uphill a problem? As long as the tie rods swing in close to the same arc as the lower arms it does not really matter if the arms are not parallel to the ground plane. Do you have enough suspension travel with it the way it is? Is the vehicle too low or too high. As hotroddon notes, pictures would be a major help in determining if there is a problem here.
For instance are the arms running uphill from the lower ball joint or front the frame end.
As they say in the cl***ics; This thread is useless without pictures.

Roo

 

Is the truck fully together and with all weight on front end.
It will settle after while.I had a problem like that and cut off one full coil with hacksaw,that brought it down and better ride.

 

Here's some pics.





The truck is together and I'm driving it. The problem is its pretty twitchy, especially when I hit a bump so my guess is I've got a lot of bumpsteer. Its also got a GM P/S pump and a Ford rack so I may need a pressure control valve for the pump. I'd rather not lower it any more as its pretty low now and I've got to be careful when I drive it and not hit any chuckholes or bumps as it will rub the crossmember at the ******. Speaking of rear crossmember, this truck has a crossmember that runs just about where the header collectors are plus its also got a rear ****** crossmember. This middle crossmember sits lower then the ****** crossmember and its attached where the previous front axle locating arms or strut rods attached as the heavy duty cast iron mounts are still riveted on the frame. Do I need this crossmember since its only about a foot in front of the ****** crossmember?

 

If running down hill then in my mind, your lower A arm attaches to the frame is lower than where it attaches to the spindle, so you need to raise the the front end with either coil spring spacers or by installing taller or stronger coil springs, all of these ides will raise the car, you will have to fine tune it to get your A-Arms to run horizonal

 

It looks like the truck has softer springs than it needs for the weight you have.

Are the upper A arms sitting at the same angle? They should be. If they aren't there is something wrong with the installation besides the springs.

 

Awe now the pics so up, I guessed correctly, add a coil spring spacer the round rubber ones are nice and can get them up to 2 inches. Or you can replace the spring entirely with a taller and stronger one.

 

Every front end I put in like that the instructions said to make sure lower control arms are Level. I would call fat man at one time they were only one that for that truck.

 

OK, this one is pretty simple really. It is sitting too low for the installed height of the crossmember. You have three choices to get it working right in my mind.
1. Raise it with proper length and rate spring, of course that means it will sit higher.
2. Put in the right springs then use a dropped spindle to keep the ride height about the same (maybe slightly higher)
3. Cut the crossmember out and start over

And you can lose some of that twitchyness by installing a pressure valve in the PS , or go to a Ford Pump.

 

It dosn't look all that hateful, the lower control arm has a nice long swing and the racks' universal joint is close to alignment with the lower control arm pivot point so the are moving at nearly the same rate, i personally make a spacer or bend the steering arm so that the steering extension and the control arm are parallel with each other. I am sure other people will say that that is unnecessary, it is close enough an dthey may well be right.
We can't see the upper control arm so can't make a comment on that, I think the lower spring mount has a slight issue as it looks like the designer intended the lower control arm to be level and set the lower spring cup accordingly, in reality the control arm is running uphill and that messes with the seat - i would be willing to bet that a coil has been cut off the spring to lower the front and that would explain the lower control arm running uphill and misalignment in the seat of the coil spring.
That help?

 

Is it different from side to side or is it me? Right side looks lower.

 

oj, the problem is that MII front ends when they are that far at the end of their compression travel start to bump steer a fair amount. And I think if you dropped the steering arm to get it more parallel at that position it would just bump on droop instead.

 

I agree with whats been said the front springs are wrong. Not tall enough or two weak. First step is to get a spring that will raise the car so that the lower control arm is parallel with the ground. If I understand your description correctly the car will then be at the right ride height. If it is too high then you may need to buy and install drop spindles.

As far as the twitchy steering is concerned, install a restrictor valve in the back of the power steering pump to cut down the pressure it the rack&pinion. Drive it and I'll bet most of your problems are solved. see if

 

What you have is a Fatman crossmember kit. You have a few geometry issues here to resolve if you want to truly fix the way this drives. No amount of pressure trickery with the power steering is going to cure this or even slightly improve the situation.

I'm going to post my notes here in red so you can follow along.

Ok, here is my suggestion to your solution. It's not the easy way out but will solve many problems you have.

You are going to have to take this thing apart, at least a little bit. The spring pockets either need to come down or the crossmember needs to go up. And shoving the crossmember up may be the easier of the two to do. In a sense you will have to section out about 1 1/2" to 2" inches of the side of your frame rail and raise it all up leaving the spring pockets alone.

Here is an example of what I'm talking about.

 

Sorry, got called away and didn't finish my thought.

By sectioning the frame rail and raising the crossmember up you will fix the camber curve and get your geometry closer to correct. The springs and shocks you have now should still work and you most likely will have better ride quality too. This may slightly raise the truck and solve your clearance issues.

 

hotroddon and Mr48chev has you covered on this one. X2 to what they've said.

 

Ok I just got back home and took some readings with the angle finder. Left UCA is 10 degrees, LLCA is 9 degrees and the LTR is 11 degrees. The RUCA is 10 degrees, RLCA is 10 degrees and the RTR is 15 degrees. Not sure but I know the shop floor is fairly level but its obviously not a surface plate but the right tie rod is at much more of an angle then the other components.

 

Measuring angles without plotting the true centers of the ball joints only gets you close to the true angles. Unless you plan on calculating instant centers and roll centers, I don't see a point in providing the angles. If you do want to do the formulas to calculate those points feel free. You might want to invest in a set of scales to help you determine the CG placement and it would be helpful to know the traction coefficient of your tires.

I think for what you're trying to achieve, that is a whole lot of work for something you are not going to race.


The tie rod should be close to level for optimum Mustang II geometry, not the lower control arm as most kit parts suppliers would lead you to believe. I provided some of the basic stock Mustang II geometry points in this thread, read it if yo care to

 

This is a perfect candidate for the Crown Victoria bolt-in aluminum front crossmember complete with correct steering geometry, etc.
Just an example...

 

Thanks for the replies folks. So would the difference in the two tie rod end angles cause issues? Actually if I did something different I'd probably go with a Jag frontend.

 

Boy that elpolacko knows his ****!
Great job on that explanation

 

If the truck is level side for side and the tie rods are not the same angle, suspect the installation of the kit is sub-par.

Don't just go moving the rack mounting locations up or down, you think it doesn't drive well now? Induce some serious bumpsteer by moving the rack out of alignment and it will take years off your life.

The IFS as it is installed right now has problems that minor adjustments, trick pressure valves, spring spacers or what not are not going to fix. There is no easy answer.


If you were my customer and asked me to fix it we would be starting over from bare rails.

 

The truth hurts

 

Out of all the post that have been put up on this thread Elpalcko's is the most complete response and it the only way to make it right. If you do not follow this advise you are never going to be happy. Be smart and safe and do what ElPalcko is telling you.

 

I thought about this on my morning commute, that front end is widened. It should have at least four inches of rack extension installed on the right (p***enger) side, and to my eyes on your photos it does appear correct. Without this rack extension you will have different tie rod angles and lots of bumpsteer.

Also, if you jack the front end up and have the wheels off the ground, turn the steering wheel all the way to the right, put a piece of tape on the steering wheel at the 12 o'clock position. Turn the steering wheel all the way to the left counting the turns, put another piece of tape at the 12 o'clock position if your previous piece of tape is not. The distance between the two pieces of tape should be your new starting point to turn back half of the turns it took to get to the full lock left position.

While at that position, if your wheels are not straight ahead you will need to adjust your tie rod settings for so the wheels are straight and have the proper toe in setting.

This is just basic alignment settings, this will not cure your problems. I am putting this up for clarification and your information.

 

I bought a model A that someone put a mustang 11front end, not a kit.They cut the crossmember out of the car.It drove alright at 45mph,at 55mph it changed lanes,at 65mph you was there for the ride .After a lot of looking and talking it was installed wrong. I cut it out welded back, well worth the trouble.The car was fun to drive after that.

 

***uming you don't want to redo the suspension installation you can either raise the ride height to correct the suspension geometry and live with that, or, raise the ride height and and switch to lowered spindles to get the curb height back down again.

 

Al, look again at the shocks. If you are familiar with the Mustang II as I am, you will notice there is very little or no shock travel left from full extension. Installing new springs and trying to raise the front is a moot point unless he fixes the shock length issue.

To the OP, jack up the front until the wheels come off the ground and take a picture of that from the same vantage point you took the previous ones.

 

I see the pic you have to light a spring get a v8 spring or more lbs.The tie rod end should be about the same lenght from pivet to ends and middle of turns radius equal turn left to right.