What was involved in narrowing the crossmember and rack? What are the years of crown vic that are suitable, and are there Lincoln and Mercury? When you live in the middle of nowhere like I do, the availability of these American versions make them more attractive if I can make them work.

 

Just found a place about an hour away that has Crown vic's come in all the time. Fleet stuff. $250 for a front suspension. Not sure what years to ask for or stay away from.

 

2003 through 2007.

 

Thank you!

 

Narrowing a rack especially is NOT to be undertaken lightly, and should be done by a accomplished machinist.
Its not done by merely shortening the tie rod arms, which will screw up the steering geometry badly. Food for thought. John

 

What steering geometry will get screwed up? I'm thinking in my mind's eye it is rack, crossmember, and tie rod. shortening them and getting that right should have no affect on caster or camber right? Don't get me wrong: If you don't get the crossmember welded back together squrare, no good can come of it. But we will be aligning it after we are all said and done correct? As long as we didn't use up all of our adjustment we are golden.

 

It will be great if Clinton chimes in on how he did his. There are probably some things to make it easier and some things to look out for.

 

I think what Lexcoe is saying is that if you shorten the crossmember, you must shorten the rack the same amount in the same area (in the center portion). If you shorten it what seems like the easy way by just chopping off the ends of the tierod arms, (the outermost portions of the rack that flex up and down) you will indeed drastically screw up the geometry, and all kinds of nasty things will happen when you drive it down the road. I have seen some other pretty M Mouse ways of shortening by using a plate attached to the center section that then has holes drilled in it and separate tie rods made up to connect it to the spindles. Another poor way to do it.

 

Lexcoe and AX are exactly right. Thanks guys. I have seen it done several other ways other than re machining the rack and for some reason it never works out as expected . I know it doesn't seem like it but it really screws with the geometry. It will never handle like it should. Take the advice, they are trying to save you headaches down the road not to mention time and money. Don't get me wrong, I have seen it done before , it just needs to be done correctly.

 

Correct, the rack itself MUST be narrowed the same amount, which often requires extra teeth be machined into a rack and the housing must be narrowed. As i said, Not to be taken lightly as lives are at stake if not done CORRECTLY. Generally not something that can be done at home without lots of experience and equipment.
At the very least it can result in a terrible handling vehicle, ive seen it done. John

 

I understand what you all are saying. If you shorten the pivoting links on the ends of the rack, you could run into bump steer with the shorter radius of travel. I would think there would be some general rules of thumb about how short one can reasonably go with rack ends given an expected amount of travel. In fact, checking out some other production vehicles may even be helpful there. Shortening the rack in the middle I'm sure is a trick.

 

the generally accepted rule is the rack inner pivots should be as near as possible in line with the lower inner a arm pivots. john

 

Certainly true. But during driving, bumps will cause it to go out of lined up. The shorter the pivot radius is, the more the toe will be affected for the wheel that moved. When one only hits a bump, you can get bump steer from short pivots. But short is a relative term. How short is acceptable for the radius? I would think that this is the "geometry" that all are concerned about. If it is something else, please correct me.

 

I'm not sure how a correctly aligned R&P pivot can move out of alignment with the control arm pivot when the vehicle hits a bump? It does move out of alignment in a tight turn, but bump steer is less of an issue then. The basic geometry of a correct R&P setup is pretty cut and dry and easily understood using HS plane geometry.

 

Ax, I think they are talking about the effect of narrowing the steering by shortening the tie rods rather than narrowing the rack ???