POP Goes the Shifter - No More!

The 280z came with a later 5-speed transmission already in it when I acquired the car. And ever since I've owned it, the car has been popping out of 2nd and 4th gear under engine braking. For years I figured it was just a sign that a transmission rebuild was in the cards eventually.

Then I came across an article that reframed the whole thing. The claim was that if you're running the original shift rod with a later 5-speed, the lower portion of the rod can contact the transmission housing where it enters - and that contact is what's causing the pop-out, not anything internal. The fix is to pull the rod, look for contact marks, and grind relief pockets at those points to give some clearance.  I pulled the rod and sure enough, the wear marks were right where the article said they'd be. I clamped it in the vise and ground the pockets.

While I had everything apart I also replaced the outer shift boot. The original vinyl unit was 50 years old and looked every bit of it - cracked, stiff, and past its useful life. The replacement isn't an OEM replica, but at this point I've already swapped in modern gauges and a classic-looking modern radio, so close enough is good enough.

After reinstalling everything and taking the car out, no pop-outs. After all these years, it was the rod contacting the housing - not the gearbox.

New Tires for the D21

Decided it was time to put new rubber on the D21 pickup. The original tires were at least 15 years old and the sidewalls had started to crack - long past due. I grabbed a set of General Altimax RT45s and figured it would be a fairly quick swap. The fronts came off no problem, but the rear aluminum wheels had other ideas.

The rears had bonded themselves to the brake drums - a classic case of galvanic corrosion from aluminum wheels mating to cast iron over the years. The night before I soaked the drum-to-wheel seam with PB Blaster and let that work overnight. The next day I reinstalled the lug nuts finger-tight, lowered the truck until the tires just touched the ground, and rocked it side to side. Both rears broke free without too much fuss.

One of the rears had a bonus surprise - a previous installer had applied bead sealer to the rim, for reasons I couldn't figure out. The bead surface was in great shape; there was no good reason for it to be there. That stuff is not fun to remove. I ended up chucking a 3M Roloc White bristle disc in the angle die-grinder and working it off that way. It got the job done with minimal impact to the rim surface.

New Altimax RT45s are on all four corners now. I have nickel-based anti-seize on order for the hub faces - the plan is to apply it at the first rotation so this doesn't happen again. Copper-based would be the wrong call here given the aluminum-to-iron contact; nickel sits in a much better spot on the galvanic scale for this application.

No vibration or pulling after driving around - truck is happy with its new shoes.