924Board.org

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

Because of the stupid design of the 924NA pilot bearing, you can get a normal puller inside of it.

You have just about one shot with the type of puller that threads into the bottom of the NA's housing.

The 931 uses a pilot bearing that is easier to deal with.
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

DentalFlossTycoon · Joined: 27 Nov 2016 Posts: 38 Location: Bozeman, MT

It’s worth noting that the early style 924 NA pilot bearing does not have the threads at the inner end; it is an open cylinder with no provision to remove it. With the engine still in the car, I pulled the flywheel off and soaked the housing in PB Blaster. Then I drilled two holes in the bearing housing portion that sticks out (which is not easy to do) so I could put a pin through them (perpendicular to the crank).

The pin had to be a hardened drill bit that I cut to about 22mm in length. I bent smaller drill bits and other hardened steel pins. I think I used a 7/32” drill bit but don’t quite remember. Then I cut a piece of 10mm diameter all-thread to about a 10cm in length and drilled a hole in one end perpendicular to the length of the piece, so I could pass the pin through the holes in the housing and the holes in the all-thread. Then I assembled the all-thread and pin thorough the housing surrounded by a 32mm socket up against the engine, so the square driver end of the socket faced the back of the car and the all-thread came through it. Heavy washers and a nut on the exposed side of all-thread competed the tool.

Before pulling the housing, I had the secure the engine from turning, using a ratchet strap and socket wrench on the pulley at the front of the motor. Back at the pilot bearing I could then slowly tighten the bolt on the all-tread, and it gradually extracted the pilot bearing. It took a lot of effort and force, but eventually the housing came out of the crank (and remains stuck in the socket with the all-thread, pin, nut, and washer).

This process took me weeks to figure out. Sorry I’m not quite sure how to post pictures to show it, but here is a link to a video of the socket and housing after they came out of the vehicle.

https://youtube.com/shorts/ye9CSJComOs?si=3gIogy3M4UxqbpKV

Riggard · Posted: Tue Nov 28, 2023 7:09 am Post subject:

Just purchase something like this, took me about 5 minutes.

It also works great for replacing the SuperCharger bearings of an m45, but that's another story

DentalFlossTycoon · Joined: 27 Nov 2016 Posts: 38 Location: Bozeman, MT

Even if I could just buy something like that, I don't think it would have worked in my situation.

Riggard · Posted: Wed Nov 29, 2023 6:42 am Post subject:

Yeh I find it hard to envision what you did exactly. Only thing I can tell is that I removed the bearing (not the sleeve, as I don't see the need to do that) from my '78 engine with ease.

DentalFlossTycoon · Joined: 27 Nov 2016 Posts: 38 Location: Bozeman, MT

My bearing was completely destroyed before I pulled the thing apart (only the outer casing of the bearing remained inside the sleeve, basically fused in there), so the old style sleeve had to come out of the crank. I did it with the engine still in the car and the torque tube and transaxle slid back, leaving little space to work. Next challenge is to get the new breading and sleeve into the crank, but I have a plan for that as well.