Front Hub Retaining Rings

I needed to rebuild the front hubs on the 330GT I’m restoring. There were some design changes in the hubs from early 330GTs to late 330GTs, and these were evidently the later hubs since they came off a SII 330GT. Earlier hubs had a felt seal and a slightly smaller rear bearing that carried over from the 250 hubs, but later ones like this went to a more modern lip seal to keep the grease in place. Behind the grease seal were two locking rings that secured the bearings, and I needed to make a tool to remove this locking ring.

Since I wasn’t able to find a tool that could drop into the hub to remove the locking ring, I decided to make one from scratch. I turned a piece of steel to the correct diameter and drilled four holes to match the holes in the locking ring. These holes would accept hardened drill rod to index in the ring and I welded a large bolt to the center of the tool so my impact gun could try to break the locking ring free.

The locking ring was pretty tight, and I manged to break a couple of pins from the force, but eventually, the first locking ring came out.

The problem was I machined my tool to reach the first locking ring, but there was a second one further down inside the hub, and my tool was too wide to make it past the threads securing the first locking ring.

I put the took back on my lathe and took some more material off to fit into the second step so the second locking ring would come out.

These hubs were handed, so one side would turn counter clockwise to release, while the other one would turn clockwise to release.

When I got all the locking rings apart, I could see someone had taken one of the hubs apart before, and probably didn’t have a tool to do the job because the holes in the locking ring were pretty beat up. Luckily, I didn’t do more damage to these rings since I now I have a nice tool to get the job done. When it was done, I threw the tool in my drawer full of specialty tool wondering how many years from now that I’ll be needing it again!

I posted a video version of this blog post here.

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