5x4.5" on the big GM rear uprights

[FieroWanaBe1]

I've modified the A-body knuckles before on my never ending Chump-Car project to use S-10 bearings, I wanted the 5x4.75 flange for C5 wheels.
The bore needed to be opened up, as well as the threaded holes drilled out and slotted to meet up to the 3x4.75 flange hole, which is threaded on the S10 and on the Jeep Unit.

The unseen benefit is the SUV units have a larger shafts and housings, and would be a stronger design than the GM Sedan units. The A-body 27-spline, if I recall, was not the same as diameter as the S10 27-spline.

[draven]

Will, Eric, anyone else....

Do you think you could CAD up a top and bottom piece to these corvette modular spindles if I bought a pair and/or obtained some measurements?

https://www.lateral-dynamics.com/

[The Dark Side of Will]

In terms of getting their claimed structural results, a lot depends on getting the tolerancing of the joint correct... they didn't make that simple/easy

[draven]

In terms of getting their claimed structural results, a lot depends on getting the tolerancing of the joint correct... they didn't make that simple/easy

Explain further please.... as this is definitely in 'your' wheelhouse...

Working more on the LF3 swap and it keeps nagging that I'll sheer the rear fiero stubs eventually or the shallow splines on the cobalt turbo axles or wear out the cavalier hubs I have the rear uprights machined to take (I have two spare sets and the cavalier bearing/hubs are good units but OEM NOS are starting to thin). This is all speculative, and a bit in the future, but before I make a jump to DSS axles and the associated cost I figured I'd look at something like this as an upright solution and piece a corvette outer stub onto some saab axles.

Figured this might be easier and cheaper than starting with a full redesign of the rear uprights that you have been working on....

[The Dark Side of Will]

To have unbreakable outer CV's and hubs on the rear of an '84-'87 Fiero:

Obtain the knuckles, ball joints, brakes and axles from a '92+ Dustbuster (U-body) minivan. These us the same front brakes as LT1 F-bodies.
From here you can (I think) plug the 33 spline outer CV's onto the stock Fiero manual transmission axles.
The larger shank ball joint bolts into the Fiero control arm and the toe link plugs right in.
This gives you a very strong 5x115 pattern hub and extremely strong 33 spline outer CV, along with 11" brakes.

To go even a little further, you can spot face the inboard sides of the hub mounting bolt holes and drill out the threads. Then you can use 2nd Gen W-body bearings or C7 Corvette bearings. Since these bearings are for use with aluminum knuckles, the flanges are threaded and the knuckles must have clearance holes.

The only thing my knuckles will do is allow use of a parking brake, a wider selection of rear brakes and be lighter. If you want strength, you can get that via stock parts from other cars.

[The Dark Side of Will]

In terms of getting their claimed structural results, a lot depends on getting the tolerancing of the joint correct... they didn't make that simple/easy

Explain further please.... as this is definitely in 'your' wheelhouse...

Look at how the ball joint bosses fit into the surrounding metal, and how that projection in the middle of the bolt pattern would interface with a ball joint boss. That all has to be tightly toleranced to be effective at keeping the strength of the joint up.

That being said, the Fiero front end is hella lighter than a 1st gen Camaro front end, so it might not matter.

*THAT* being said, they make those things WAY more complicated than they need to be... there's a fair bit of machine time and multiple tool changes in making those parts.

[ericjon262]

Will, Eric, anyone else....

Do you think you could CAD up a top and bottom piece to these corvette modular spindles if I bought a pair and/or obtained some measurements?

https://www.lateral-dynamics.com/

Those look like cool parts, but I wouldn't feel comfortable taking a part like that on quite yet.

[draven]

To have unbreakable outer CV's and hubs on the rear of an '84-'87 Fiero:

Sorry...Running an 88... I should have mentioned that..given that this thread was for '84-'87's..

I guess if one were so inclined one could probably rebuild something similar to the Ryan/Held/Arraut/??? bump steer kit to mate to the horizontal and lateral links to run these on an 88..

[ericjon262]

To have unbreakable outer CV's and hubs on the rear of an '84-'87 Fiero:

Sorry...Running an 88... I should have mentioned that..given that this thread was for '84-'87's..

I guess if one were so inclined one could probably rebuild something similar to the Ryan/Held/Arraut/??? bump steer kit to mate to the horizontal and lateral links to run these on an 88..

That idea probably won't work, I'm 99% sure that the 88's strut mount on the knuckle is at a higher angle, and they are definitely offset from the axle centerline, whereas the 84-87 is inline with the axle CL.