rover73

I have an 85 300td that is in need of new axles. My car has the Homokinetic Axles that have the "can" on each end where both ends of the axles look similar.

I checked out a few part suppliers and they are selling the Annular type Axles with 6 or so bolts on one end.

Are these axles interchangeable without any modification?

Outre

The Annular and Homokinetic ones are interchangable. With the exception that there may or may not be spacers inbetween the Axle Shaft end and the Differential to adjust the end play of the C-clips that retain the Axles in the Differentials.
The manual has that the C-clips should be able to be pulled in and out easily but that there is no end/in-and-out play of the Axles.
There is different thicknesses of spacers to adjust that.

The Asian made Annular Axles have had issues with the Bolts coming loose.
There is also Asian made Homokinetic Axles (GKN or GNK, cannot remember) and they do not have the loose bolt issue.

Both types of Asian made axles sometimes have problems in that the Spacer will not lay flush against the Axle Housing due to the machined radius being too thick or the Groove that the C-clip goes into is too wide (there is different thicknesses of C-clips but the groove widths on tha Asian ones are sometimes too wide).

If I were to buy some Asian made Axles I would get them from a local store. That way if there was a warranty I would not be stuck paying for the shipping just to get the warranty.
It is also simply faster to deal with a local store.

If you are paying a Shop to install the Asian Axles and they are supplying the parts besure to let them know that if there is a warranty the shop has to pay to do the job again if an Axle goes bad under warranty.