Matching up an early 915 to 87 trailing arms
 

I've got a 75 915 with 4-bolt 2-stud flanges for the inboard CVs, same as outboard mating up to 73 stub axles in steel trailing arms.

I want to put a set of 87 trailing arms in the car. Can I pull the hubs out of my steel arms and insert them into the later ones? What are my options for getting the axles to work?

just move the four bolt stubs to the new arms and you are good to go

Actually the bearings in the aluminum arms are a little wider so it won't be ideal. The stub axle won't stick through as far. It will bolt up but you won't get the kotter pin through.

You could swap your inner cv joints onto late axle shafts though.

Wish I was at work to look on PET to see if the part numbers are the same for the stub axles on '73 and older, and '74 on.

Thank you Chuck, thank you Tyson. Looking at 74 PET and an 86 PET, there is no direct correlation, but close. I think the best thing I can do is pull the 87 axles out and measure the all-in-one stub compares against the separate early one, and of course push one in and see what it does. Still have to dismantle the parts car I got recently for its upgrades. I know on the transmission side there are different splined flanges and I thought trailing arm wasn't completely plug and play as well.

Swapping CVs might work too.

Appreciate the help.

I believe you should be o.k. like Chuck said. I believe the flanges for the steel and aluminum arms are different to compensate for the wider bearing, and the stub axles are the same length.

Thank you Tyson.