Our 83 still has its original cap after 21 yrs. We've had our son's 81 for 2-1/2 yrs and it has 290k mi. It came with a very spiffy looking shifter cap, but when I removed the handbrake console, I discovered the original - but unbroken - cap with yellowed (formerly white) gear position numbers. Obviously a P.O. lost it and sprang for the new one.

So, in my experience, no breakage. But rattles? oh,YES. Both of them rattled, but closer inspection showed that it's the OD switch button...a fingertip on it (in both cars) stopped the noise. So did a thin piece of foam rubber cut to fit under the cap, with a square hole that just barely contacts the switch button. Enough to stop it vibrating, but not so much that it impedes its movement.

Hmmm - yeah, a stainless (or aluminum) cap with embossed or carved shift pattern would be cool!
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Bob (81-244GL B21F, 83-244DL B23F, 94-944 B230FD; plus grocery-getter Dodge minivan, MGB, and numerous old motorcycles)