Can't get momo hub to slide onto steering shaft

[fusion]

Hello, I have a 76 280z.  I am putting a momo 3503 hub adapter onto my steering shaft. 

 Every video I've watched of people putting hub adapters on their s30 it seems they slide right on.  

Mine goes on very snug, but I can get it to go on about 6mm or so before it gets really hard.

Maybe I could pound it on, but doesn't seem right and I don't know how I'd ever get it off.  I have checked the splines on both the hub and shaft and they look OK.  I even bought another hub and tried that with no success.   I have 2 other steering shafts laying around and it's always the same thing.

 

 

Is it possible both the hubs are bad?  Bought both from Amazon (not 3rd party either, from Amazon directly).  The splines on the Momo look cast (not machined) and perhaps that's the problem?

Not sure where to go from here.  I like the collapsible design of the Momo but may have to consider another brand.

Thanks for any advice.

[Patcon]

Are you sure that is the proper adapter for the s30?

Have you tried contacting Momo?

[SteveJ]

11 minutes ago, Patcon said:

Are you sure that is the proper adapter for the s30?

Have you tried contacting Momo?

It's the right part number. https://www.amazon.com/MOMO-3503-Steering-Wheel-Nissan/dp/B000F0KG9A

 

[Patcon]

Then I would start with Momo

[fusion]

To update this thread:  after further analysis it appears that a portion of the internal splines on the adapter were not fully formed (look at 6 o'clock area on both pictures for comparison)

 

Good splines:

Misshapen:

This was the same on both hubs.

I emailed Momo with no response.  I ended up cutting the splines off one of my extra steering shafts and pressed it though the hub as a broach.

It still didn't slide on by hand, but it went on fairly easily with the nut.

 

If I ever need to remove it, I'm assuming I will have to use a steering wheel puller to get it off.