Inner CV Joint Confusion

DPDISXR4Ti

Registered User
I've read an assortment of conflicting info about what inner CV Joints were actually used on the SC. Some have suggested that if smaller ones are found on a SC, it's only because a half-shaft(s) was changed at some point, and the one from a NA car installed. I've seen other suggestions that right and left sides are purposely different, from the factory. Does anyone know what the real story is here?

My purpose for asking is a bit different. In the Merkur world, we do 8.8 IRS conversions using SC or Mark VIII pumpkins with inner joints along with custom hybrid axles. The Mark VIII inner joints always seems to work out fine, but there have been some instances with the SC donated joints being too small for the 1 1/8" hybrid axles. Can anyone shed some light?

Thanks,
 
Stock SC shafts are 1-3/16" diameter and fatshafts measuring 1-1/2" for passenger side of 5 spd cars. Anything smaller came from a Normally Aspirated V-6 T-Bird
 
Jim Cook said:
Stock SC shafts are 1-3/16" diameter and fatshafts measuring 1-1/2" for passenger side of 5 spd cars. Anything smaller came from a Normally Aspirated V-6 T-Bird

Thanks Jim. I should have pointed out that I was referring to the major diameter of the inner splined section of the axle, which (more precisely), measures 1.16". Is this consistent on the SC axles regardless of the different shaft diameters you've indicated above?
 
All stock SC inboard Tripod joints look like the upper shaft regardless of shaft diameter. V6 LX shafts look like the one below. Picture doesn't show it but Tripod bearing assembly is larger too. Maybe I'll take another picture later. If you are referring to the internal splines of the tripod bearing assembly, I've never taken a shaft apart to look. Since the last of the fatshafts produced by GKN neck down to 1-3/16" at the tripod, one could assume that the internal splines of the tripod bearing assembly vary with shaft diameter. You could call Marty at Raxles, he could most likely give you the info you seek.
 

Attachments

  • DSCN0319.jpg
    DSCN0319.jpg
    83.4 KB · Views: 185
Jim Cook said:
If you are referring to the internal splines of the tripod bearing assembly, I've never taken a shaft apart to look.

Indeed I am. I'm pretty sure there are two sizes here, and I imagine it's consistent with your pic above of the two tri-pods. That's what I'm not certain about however.
 
V8 LX inner joint

I realize this is a really old thread, but thought I would give it a try anyway. Would anyone know if the V8 LX inner joint shafts that go into the diff are the same diameter as the ones used on the SC? Using the picture above as an example.
Thanks.
 
I realize this is a really old thread, but thought I would give it a try anyway. Would anyone know if the V8 LX inner joint shafts that go into the diff are the same diameter as the ones used on the SC? Using the picture above as an example.
Thanks.

I believe only the N/A V6 cars got the smaller diameter shaft as shown above. I believe V8 and SC should be the same (larger) shaft size IF original.
 
Early 5 speed SCs got an even bigger shaft on one side (left IIRC, but I won't swear to that) due to the shock loading of the clutch.

Otherwise, all V8s got the same shafts as the SC auto did.

The Mark VIII shafts are supposed to be a bit beefier; but it's not that much difference.

RwP
 
Back
Top