Seized parking brake clevis pin

[centauri]

Hello from California. I'm refreshing the brakes on my '77 Elite 504. Workshop manual states the rear differential must come down for access to the rear cylinders. Hit a snag on the right side, the clevis pin connecting the cable to the cylinder arm won't budge after removing the cotter pin. I've soaked it in penetrating oil, hammered it from below with a punch, pried with a small screwdriver.  The joint swivels but the pin just won't slide up more than a millimeter.  I can get vice grips on it from below but then, no room to rotate the tool.  Access to this area is extremely tight, so went ahead and disconnected the diff everywhere else, now its propped up on jacks, hoping a bit of room to work would help, but it didnt buy me much, and it's still stuck fast.  I started Dremeling from the top but there's just not room to make safe or accurate cuts. I'm afraid to use heat for the same reason, it's too cramped a space, hard to reach and close to the fiberglass.

Is there anywhere else I can disconnect to get the diff assembly loose?  Or a tool or trick that might help with this?  If I do ultimately have the cut the cable, are there replacements?

I see 4 bolts around the inner shaft, does this mean can the rear brakes be fully rebuilt with the diff still on the frame, or am I doing things the recommended way?

 

 

[snowrx]

 A heavy C-clamp with a little socket over the pin head? Or something like a motorcycle chain breaker?

Can you get enough slack to lift the swaged cable end out of the link?

[EXCEL V8]

Hi Doug - welcome to the forum!.  You might be able to get a long-series drill to reach up to it.  Maybe the heat from drilling will release it.  If you end up cutting the actuating arm I can help you out with a replacement.  Don't know how much postage would cost though?

Pete

[centauri]

Thanks Thomas!  A small C-clamp with a socket over the pin head worked like a charm.  My diff assembly is now on the floor ready for a refresh, the cables and boots are unharmed.  Great to learn new tricks!!

[EXCEL V8]

Well done!  When checking the diff internals make sure that the outer races of the crown wheel carrier assembly bearings aren't fretting into the casting itself - I had to re-machine mine in this area and I have a couple of spare diffs that are the same.

You can see the wear lip here: 

 

 

After I had machined the same area:

               

I commissioned some new outer races to be made with a larger rear face to help reduce this problem - larger contact area.  Obviously the shims packs need altering following this work!

Pete