79-93 steering racks - does one size fit all???

[Hissing Cobra]

I had a friend of my brother's do the initial alignment. He owns an alignment shop and the whole thing needed to be aligned as I had installed the K-member, used steering rack with new outer tie rods, new ball joints, new struts, new springs, new wheels, new tires, new wheel bearings, and new brakes. I also changed all the bushings in the front end with polyurethane units. Once done, the wheel alignment was way off and I had it towed to his shop for the alignment. When I got it back, it tracked straight and there was no abnormal tire wear. In fact, those tires were on the front for the past 9 years and over 40,000 miles before I replaced them earlier this summer. The car has always been "touchy" like that on the highway and I've had comments from people who have driven it. I thought it may have been problematic due to my old power steering pump, which was the original one for my 2.3/turbo Cobra but my brother and I swapped that out this summer for a V-8 unit out of an '87 GT and it didn't change anything. I'm going to check my rack this afternoon as I haven't gotten the time to do it yet. After I check it, I'll get back to you. Oh, another alignment will be done as well (after I figure this out). I appreciate your replies.

[wraithracing]

I still wonder if this is an alignment issue, caster in particular. Toe and Camber are generally what cause tire wear. If the toe is set well, even with the camber off the tire wear is generally minimal. I just wonder if by swapping in the K member and all the other parts the caster is too little and that is causing the "touchy" steering on the highway. Unfortunately Caster is not adjustable with the OEM plates and require C/C plates to make it adjustable. Essentially as the caster becomes more positive (struts leaning back towards driver) the steering becomes more stable with less "touchyness".

Since the problem has been there since you did the swap and has stayed the same even after tires, I don't think the tires are the issue, although tires can cause the same issues you are describing when you have one tire that has begun to separate internally or have other manufacturing defects that can be hard to see.

Check out your rack and we can go from there. I still don't think that is the issue. If you don't have any steering issues other than the "touchy" feeling at highway speeds, I still believe a complete alignment check would be a better place to spend money than a new rack. Truthfully a set of C/C plates and a new alignment will most likely fix the problem IMHO. But I have been wrong before. Let us know what you find out with the rack.

Good Luck!

Trey

[82GTforME]

The 20:1 remanufactured Ford rack (Cardone) I just put in my 82 acts the same. It seems very sensitive to say the least. New rims and tires are 8" from the prior 6". More front end stuff changed from 4 to 5 lug with 94 spindles.
I can't say if it is bump steer partially (because I can't say I've experienced it before) or whether it is the wider tires tracking. It may be the rack itself. I had mine aligned at a shop so I'm not assuming that to be the initial issue. The car is stored already for the winter but next year I am going to re-bleed the system from scratch again.
It can feel a little scary when going quickly. Just way too sensitive and touchy which I don't think is quite right.
Good luck, I'll be keeping tabs on your solutions.

[wraithracing]

Wider tires can cause the tracking issue (tramlining) where the tires want to stay in grooves or depressions on the road/highway. If this occurs at the same speed on different roads, then most likely it's not the tires.

Switching to the 94/95 spindles and using stock Fox length lower control arms causes the camber to immediately become more positive by 1.7 degrees. The only way to correct this is to either switch to the longer 94-04 control arms, aftermarket arms, T-Bird arms or install Caster/Camber Plates. I would recommend the C/C Plates either way as they allow you get a better quality alignment. Again as I stated before, there are a lot of ways to do alignments and most shops do the quick and easy. Unfortunately on Fox bodies that have modified suspensions this is not the best option and can lead to a lot of headaches and issues. I would recommend anyone having an alignment done to their vehicle have the shop print out the before and after measurements so you can see what was done. The Factory tolerances are pretty wide and when I worked as a Service Manager I required my techs to split the tolerances so we did a "tighter" tolerance alignment. This is more work for the tech, but we had fewer issues and come backs due to alignment issues.
Just an FYI, the specs that Maximum Motorsports lists with their C/C plates for the Foxes are:

3-4 degrees of positive caster (not adjustable without C/C Plates) with no more than 0.5 degrees difference side to side
0.75 degrees negative camber +/- 0.25 degrees
0.5 degrees total toe in (Which is @ 1/4" toe in or less. Usually 1/16"-1/4" works well for most Foxes, but individual tire wear can vary, so adjust as needed for tire wear)

As for rebleeding the rack, usually air in the PS system shows up as jerky or loss of power steering when turning. If you don't have those symptoms, then I would believe your system is bleed completely.

Hope that helps some.

Trey

[Hissing Cobra]

Trey,

Thanks for all your help. I haven't had a chance to check my rack yet, as I've been working a side job but I should be able to get to it this weekend. I forgot to mention that I have the stock caster/camber plates in my previous post. I'm definitely going to get it realigned but I have a question. If the toe is good but the camber is off, I know I'll need the aftermarket caster/camber plates. If the camber is then reset to a better position, will I have abnormal tire wear?

[wraithracing]

There is no guarantee that you "have" to have C/C plates to adjust the camber. C/C plates will allow you more camber adjustment and the ability to adjust the caster. I do believe strongly that the @$210 for Maximum Motorsports plates is money well spent. In fact they are running their Deals of the Day, so if you keep watching you should be able to pick up a set for up to 20% off.

Caster and Camber both can affect the toe setting so you set those first and then set your toe. Caster is something that can be in a range and as long as the two sides are within .5 degrees you should be fine. As I stated above, the 3-4 degrees of Caster is a great place to start, but nothing says you have to run that much either. For a street car you don't want to run more, but you can definitely run less. The camber setting listed above should work pretty well too, but as with every car it can be different.

So in a long round about way to answer your question, No you shouldn't have abnormal wear even if the camber or caster are adjusted. Hopefully with C/C plates and a quality alignment your "Touchyness" on the highway will be cured and your tire wear will be the same.

Trey

[Hissing Cobra]

Thanks! I'll be back at some point soon with the rack info.

[CapriGT]

FWIW: I have driven the Cobra a number of times through the years. steering always felt touchy, but this year it seemed more sloppy. I would have suspected a worn rag joint if the car actually had one