I am going to replace both the LCAs and the UCA but dont know which one I should get as adjustable. I would think since LCAs are longer and more prone to flex I would get them as non-adjustable and get an adjustable UCA since I would only have one adjustment instead of two. Also, is there any reason to do both? My car is a DD that sees a drag strip maybe twice a year but will be at Hallett Motorpark (high-speed touring car track) at least once a month except for in the winter.

if this has been answered before im sorry, but the search feature kept kicking out the words LCA and UCA because they are only three letters.

 

It's all personal preference. I don't think you're going to have problems with flexing on the LCA's, but, like you said, it's two adjustments that you have to match up instead of one. However, keep in mind, it's a b!tch and a half to get to the UCA to make the adjustments whereas the LCA's are easily accessible.

 

both my UCA and LCAs are adjustable.i dont think that it is necessary so long as one of them is. but like Texotic said, the upper is a real pain to adjust. the only reason i replaced it was because i had the rear axle removed for a gear swap and it was easy at the time. the lowers are easy, but you just have to make sure they are the same length.

 

Is there any reason why I would need to adjust it after setting the pinion angle?

 

once its set, i dont see why you would. i've never had a reason to readjust mine.

 

If you get LCA relocation brackets, changing the angle of the LCA's will slightly alter the length they need to be to keep the same pinion angle. For instance, there different angles of the LCA's are better for different applications (think road course vs. drag trip) and if you want to kep everything aligned correctly the pinion angle must be altered very slightly. Honestly, unless you're the one doing the alignments, you won't gain anything from having the LCA's be adjustable. If you're like 99% of owners, you'll just have a shop do all of your alignments, so the ease of adjusting won't matter. If you can afford it, my favorite setup is Steeda's billet LCA's (non-adjustable, but the bushings are maintenance free) with the Steeda Competion UCA (adjustable). Those are higher end pieces, though and I don't plan on installing a UCA until after I'm already lowered, so I got adjustable LCA's to make sure I could adjust my pinion angle until then.

 

Adjustable LCAs can also be used to square the axle in the chassis (thrust angle, on an alignment print-out). It is something worth considering if you expect to eventually add LCA relocating brackets, as you can use the LCA adjustability to cover for tolerances in the relo brackets and errors in their installation.

LCAs are not supposed to be loaded in the directions where they might look "flexible". I'd start with just them, and if you don't get wheel hop just leave the stock upper alone (I've heard it's a lot of work to swap, remove fuel tank first kind of stuff)


Separate hint: try searching for UCA* and LCA*. The added '*' character normally lets you find three-character matches because no fourth character is still a match for a wild. Tip I learned on another forum, actually.


Norm

 

The benefit to adjustable LCA's is that they let you adjust out any axle skew, i.e. the axle is not perfectly perpendicular to the chassis.

In a previous post it was suggested that changing the rear of the LCA to a different mounting point on the LCA Relocation brackets does not affect the pinion angle as the holes in the brackets are drilled on an arc to allow this. My Steeda brackets are drilled on an arc and I think the BMR fellow confirmed this for theirs.

My understanding is that the major benefit for changing out the UCA is to improve wheel hop and it has been suggested that the best UCA is the Steeda 555-4109 as this also has the option of making the UCA longer, it has two mounting holes in the bracket, and the longer arm length helps geometry. WARNING - installing the 555-4109 on the longer arm length is a real PITA

 

That is the design intent with at least some of the relo brackets. Maybe even most of them. But fabrication tolerances (and the occasional out-of-tolerance piece) plus any sloppiness during the relo bracket installation and tolerances on Ford's OE axle brackets that they attach to mean that there is still some possibility of pinion angle change happening.


Norm

 

Norm

Do you know the factory spec on the S197 pinion angle?

I just checked my Haynes manual and can't find it in there. The Steeda 555-4105 instructions say "Best angles range from 2 degress to 5 Degrees down."

When I do my spring track readiness checks I'll be double checking this again.

Thanks