Swapping control arm side stub axles, using same hub

[75 911s]

Before I take everything apart I want to make sure this is possible:

I have two sets of control arms:
1. 1975 (early) with 4 bolt axles.
2. 1977 with 6 bolt axles

Goal is to put the 77 control arms on the 75 (I have new bearings and special studs pressed into the hubs)

Can I simply take the big nut off the hub, and slide the CONTROL ARM stub axle out of each and swap them?

So now I have the 77 control arm with the early 75 style 4 bolt axle. This way I don't have to change the stub axles in the 915.

I was looking at the pet for 74-77. They show only one hub for all the middies (Item 11 in pic).

They do show two CONTROL ARM stub axle (item 13 in pic) part numbers (one 4 bolt and one 6 bolt for the later style)

This tells me the hub splines are the same for the CONTROL ARM stub axle right?

How hard is it to press out the stub axles assuming I can make the swap?

Am I over complicating this? Don't tell me that the 4 bolt axle will just bolt to the 6 bolt control arm stub...

[wjdunham]

You should be fine - I did a similar swap, I put a 915 trans with the 4 bolt flanges in a '69 and upgraded to the aluminum control arms. I was able to pull #13 out of the 69 steel control arms and fit right in the aluminum arms without having to swap #11, splines and diameter of the hub were all compatible.

I was able to re-use my early 4-bolt half shafts that way.

Hopefully that makes some sense...

[75 911s]

It does! Going to try, thanks!

[spuggy]

Originally Posted by 75 911s

Can I simply take the big nut off the hub, and slide the CONTROL ARM stub axle out of each and swap them?

That should work.

Originally Posted by 75 911s

I was looking at the pet for 74-77. They show only one hub for all the middies (Item 11 in pic).

I believe from when I looked that the hub part # goes much earlier & later than just 74-77...

Originally Posted by 75 911s

This tells me the hub splines are the same for the CONTROL ARM stub axle right?

Yup, pretty sure the splines didn't change; I believe the hub will accept the 4xM10 (+2 pin) 108mm stub, the 6xM8 100mm stub - or, if you remove stub part #13 entirely, the 86-89 "attached stub" G50 axles (which mate to a 6xM10 108mm flange at the transaxle).

So another option would be to convert the transaxle to 6xM10; press out the 2 pins, tap for M10, remove part #13 and fit 86-89 G50 axles.

For a late (fine spline) 915, either use 6xM10 108mm 85.5-86 915 flanges (kind of rare/unobtanium) - or G50 flanges machined down to suit (shortened internally 20mm or so, IIRC).

[75 911s]

Is this antiseize?



Edit: never mind - it is.

So yeah they swap.