stronger halfshafts?

aroot1

SCCoA Member
Are there any upgrades for the stock SC (early 89) halfshafts other than the DriveshaftShop stuff ($1500+) out there? From what I 've seen in my forum searches here the SC and Lincoln stuff is about the same, and there doesn't seem to be any good way to swap pieces parts to make the shorter cobra stuff work. XR7 Dave seems to have put a hybrid setup together in another post, but it was using probly unobtanium cobra R inner cv's and center pig, and if I understood correctly still the weak 28 spline outer hub where they all seem to break (please explain if I misunderstood what you did there Dave). I am putting the irs out of a scraped 89 under my 92 f150 flareside with the corbra hubs and disks and am concerned about braking axles. I have DLF's bushings for the knuckles, and mark VIII lca's with bushings to control wheel hop as much as possible, and plan to brace the iron center section as well. The subframe is going to be rigidly bolted to custom frame mounts (no bushings=no movement). I am putting a remote mount twin turbo setup on the truck, so figure the weight is about the same as SC, with maybe a little more fron bias, but around 600hp. Anyone who has tried anything to upgrade this area of the car for the bigger power numbers being made out there, I would love to here your solutions/ideas, and any help would b great
Adam
 
Are there any upgrades for the stock SC (early 89) halfshafts other than the DriveshaftShop stuff ($1500+) out there? From what I 've seen in my forum searches here the SC and Lincoln stuff is about the same, and there doesn't seem to be any good way to swap pieces parts to make the shorter cobra stuff work. XR7 Dave seems to have put a hybrid setup together in another post, but it was using probly unobtanium cobra R inner cv's and center pig, and if I understood correctly still the weak 28 spline outer hub where they all seem to break (please explain if I misunderstood what you did there Dave). I am putting the irs out of a scraped 89 under my 92 f150 flareside with the corbra hubs and disks and am concerned about braking axles. I have DLF's bushings for the knuckles, and mark VIII lca's with bushings to control wheel hop as much as possible, and plan to brace the iron center section as well. The subframe is going to be rigidly bolted to custom frame mounts (no bushings=no movement). I am putting a remote mount twin turbo setup on the truck, so figure the weight is about the same as SC, with maybe a little more fron bias, but around 600hp. Anyone who has tried anything to upgrade this area of the car for the bigger power numbers being made out there, I would love to here your solutions/ideas, and any help would b great
Adam

Automatic or manual transmission ?

David
 
Its a 5 spd, orig truck trans. Rebuilt last year, got a short throw shifter, but still not the highest perf. piece. Will be granny shiftin, no power shifts. It is also a street build, so no intent for slicks, or even drag radials. If the trans proves to b a weak link, it will be upgraded then
 
I personally would not solid mount the differential. It should have some cushion to reduce the shock loads that will be transmitted to the axles and hubs. The power won't hurt anything, it will be shock loading that will break stuff.

Wheel hop breaks all sorts of stuff, not just axles so I would concentrate on eliminating wheel hop and the rest will be fine. Most likely you won't have wheel hop issues with all the bushing work you have done but if you do still have wheel hop you can add a trailing link to the upper control arm to completely eliminate any remaining hop tendencies.
 
...It is also a street build, so no intent for slicks, or even drag radials.

If you eliminate wheel hop (or just don't let the wheels hop) and don't plan on using drag tires, then you shouldn't have to worry about it - especially with a truck.
 
I'm solid mounting the subframe assy. to the truck frame then boxing the rest of trucks orig frame from engine crossmember to just behind newly mounted SC sub. I was not planning to solid mount the diff. it'self, but brace it. I was thinking poly front bushings, and some of supercoupe performance's stuff, rear brace and new Hefty rear mount, and possibly a rear gridle cover, as I have had great luck with those on straight axle 8.8s. I also saw XR7daves comments about bad inner upper bushings nylon inserts, great info there, had no idea they were readily ava. and easy to do! I figured on cheaping out at first, till I sorted the whole package and doing axles when I was forced to jump off that bridge, I'm feeling alot better about that after some of the confidance others have! I've also seen others here weld tubing into the upper from front to rear just inboard of outter bushing, and outboard of the inner, just making sure to clear the shaft at full suspension movement. Is that worth doing? It'll only take an hour or so in the shop to do both.
Thanks
Adam
 
I spoke with a person today that has the ability. They specialize in cv axles for a little different usage. We will probably need a group of people doing it to get them made, but he said pricing should be considerably better than our options right now.
Alan
 
dirty dog,
keep us posted, I still think I may need something more, Thanks

Vic,
Please post up what you did to use the cobra stuff, they are alittle more than 1/2 in shorter, and most of what I've seen says they won't work? I would love to see how you did it, cause I think a good upgrade for between junkyard and autozone $$$.
Thanks
Adam
 
I spoke with a person today that has the ability. They specialize in cv axles for a little different usage. We will probably need a group of people doing it to get them made, but he said pricing should be considerably better than our options right now.
Alan

Are you talking about making new axles or new hubs? It's the hubs that we need. I've yet to see an axle break, but many, many, many hubs.
 
Dave,
its the outboard hub/stub that is common to break correct? is the cobra outer any better? I saw on the "gonna go fast" post about the "hybrid" axles you put together, could the cobra outer hub/cv be put on the stock SC shaft? Would that be worth doing?
Thanks
Adam
 
I will talk with Rusty about both, if we could get a stronger outer section only for a good price that would work out really well, I am also going to ask him about making flanges. If we could get a 31 or possibly 35 spline bearing flange and a matching outer shaft it would go really well. I really need to research it a bit more to figure out what spline arrangement could be used. What is the existing flange spline on the terminators. If the end also served as a part that fits cobra's the demand would be higher and the cost could be lower. I will try to measure a flange tomorrow and the bearing, the problem I see is that if the center gets larger and stronger the bearing will get bigger meaning the spindles will have to be bored for the new bearing od or replaced entirely. I wish I hadsome explorer stuff to look at.
Alan
 
I think the issue is the larger spline count for the outer stub shaft is uncommon. Mustang Cobra guys break their outer stub shafts as well. They are what created the market for DSS parts, not us Tbird folk.

For me, I am willing to pay for :
31 spline inner, with properly engineered shaft, larger (31, 33 spline?) outer stub shaft with new bearing and hub with the upgraded splines and the stock SC bolt pattern. From what I've talked with DSS on, the machining of the hub for mustang vs SC bolt pattern is a non issue. They just plug it into a computer with a slight setup change charge.

Probably the largest issue with axles on our cars is poor levels of engineering. They have been engineered for stock level, street performance. We need something engineered for our intended use. That means, to benefit the 5 speed guys, a shaft that is strong yet flexible enough that rather than breaking it will absorb the shock loads. CVjoint stub shafts need to be machined to limit stress points with proper machining of any dimensional transitions and be properly sized for the high shock loads these parts can see.
 
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