I'm confused anyway why the driveshaft has one U-joint and two CV joints so there will be some vibrations without cancellation by an 2nd U-joint.
Well, GriffX, IMHO this is where a corporate front office\accounting can cause these kinds of decisions that engineers get blamed & take the heat for from the public...............
The only thing\reason that I can think of is cost cutting. Remember, our beloved S197 Mustang's intended venue\purpose was
1st & foremost a mass production public vehicle w\ some retro styling for aesthetics.......at this time
performance was secondary (even though the chassis & suspension was vastly improved for better handling, ride quality & reliability) since the 2 other domestics (GM & Dodge) had pulled out of competition at the time.
Most other 2-piece DS designs in this era are either using the old std 3 U-joints (thus proper phasing when
all is properly set up\aligned within the 3* max U-joint deflection window), 3 CV joints (no phasing necessary & IMHO the absolute best scenario.....Dodge uses this design as well as some others) or using 3 reinforced flex discs (GM's answer to this) w\ the only weakness in these 3 designs (depending on manufacturer) was a too soft\weak DS center bearing carrier (what JXBPerformance is providing a remedy for).
IMHO........Ford stuck w\ using a U-joint in the front DS section to save the cost of a 3rd CV joint then softened up the DS center carrier to absorb the NVH due to the phasing mismatch between this U-joint & plunging CV joint on the other end.
You have to admit, this worked just fine IF you DROVE the car NORMALLY...........it's when the performance started getting pushed to the fore front by the aftermarket is when all this started showing its weaknesses\flaws.......by only approx 2% (reps us enthusiasts....13,200 units) of the total 660,000+ S197's sold so in Ford's corporate office\accounting\marketing departments POV, this is very acceptable from a business POV thus they left this to the aftermarket to resolve.......but who gets the blame from the motoring public?
The Ford engineers always do..........when the vast majority of the time the Engineering depts are vigorously arguing against this type of stuff.
Just remember, Ford engineers had a working IRS designed, built & vetted for this very S197 chassis, ready to go into production..........but to implement this IRS would raise the selling price per car at the time (2004) approx $5,000 (from target base $25,000 to $30,000.....to justify the development costs) so Ford corporate killed it to stick w\ the old 8.8" SRA but using a 3-link suspension to improve handling vs the old 8.8" SRA w\ 4-link suspension.......due to it being
cheaper to mass produce........instead of reading the market development direction which the Ford engineers had done thus developed the S197 rear IRS to enable the S197's to compete for market share (remember they had already done this for the 03-04 Terminators....but these cars were designed\sold as boutiques--strategically made in limited numbers--thus could command the extra pricing to justify the development costs.......more of this corporate office\accounting\marketing thinking).
Ford could have easily made a certain number of these to actually sell to really see if the motoring public at large will accept the extra costs........then make an informed decision on whether to go into full scale production.......but that meant that the Ford corporation would have to take a risk on some small potential profit loss to get the real data to see if their marketing dept strategies were correct or not concerning this part.
IMHO......the obvious answer is the marketing was proven wrong........thus why the 2015 MY got a full redesign & included IRS........but lost out on a full 12 yrs of potential profits from improved name\product mindshare when the US domestic auto market was wide open for the taking.
So, this isn't confusing to me............this is std current American corporate business practices (you name the industry........the business practices are pretty much identical in this country) w\ the #1 deficiency in most US corporate offices being simply complacency.........too resistant\cautious to change\take a risk when development opportunities present themselves thus, we now seem to always be "catching up" to the rest of the global industry business world instead of leading it........
