Driveshaft won't reach diff after diff swap

[thehackmechanic]

I just swapped the 3.07 diff out of my Euro '79. The car no longer has its close-ratio dogleg gearbox; it has a standard Getrag 265 overdrive box. The combination of the OD and the 3.07 gave me about 2800 rpm at 80 mph on the highway, but to the detriment of acceleration. I had a 3.45 sideloader from a 2800CS I'd parted out 30 years ago that I installed in order to get some acceleration back. The axle flanges aren't threaded, so I had to use longer Allen head bolts and put nuts on them, but other than that it went right in.

But when I tried to mate up the driveshaft, there's a good-size gap, maybe 3/8" to 1/2", between the back of the driveshaft and the differential input flange.

All of the diff bolts mounting bolts are still loose, and I banged it as far forward as it'll go with a sledge and a block of wood, but it made no difference.

I thought all sideloader diffs were the same size.

I suppose it's possible that it was like this before, but gap was made up by flex in the giubo.

Should I pull the driveshaft and loosen the big collar nut so the two halves can slide?

--Rob

[thehackmechanic]

Never mind. Loosened the collar nut. Worked like a charm.

[Brucey]

Never mind. Loosened the collar nut. Worked like a charm.

-that is what it is there for.....

cheers