Please read ALL of this page BEFORE you purchase ANY short shifter.
Short shifters CAN sometimes make a very irritating “rattling” noise. Notice we did not specify the Mazdatrix Short Shifters. The “probability” of “rattling” that we have arrived at is about 1 out of 3 cars!! Here are two short excerpts from the RX7 club Internet mail:
“I just installed my MazdaSpeed one last week and the short throw action is great (feels like a video game). However, now that I have used it for a week, I notice a rattling sound emanating from the tranny.”
“I’ve had the same noise from my C’s shifter. If I hold the gear lever, the noise stops. I just figured it’s inherent in the shifter. It works great. I’ve had it about six months.”
Our Mazdatrix shifters can also have this “rattling” noise. We have found it to be CAR SPECIFIC, not shifter specific !!
The tests we did (various years of cars) were:
1) Take a rattling short shifter out of one car, and install the same shifter in 2 others — NO rattling in the other cars.
2) Take a non-rattling short shifter out of a car and install THREE other new short shifters — NONE rattled!!
3) Take a rattling short shifter out of a car, and install THREE other NEW short shifters — EVERY ONE rattled.
Conclusion: the rattling is CAR SPECIFIC !!
We have spent a LOT of time attempting to find why they rattle in specific cars — we have NOT found any reason !!
The wire spring on the later cars (that “latches” over top of the lower ball, and is usually broken) is NOT the factor. We had them rattle in cars with a good spring, and not rattle in ones with broken springs.
The nylon bushing at the very lower end ball (as used on the 93-95 shifters) was not the factor. We had them rattle / not rattle without the bushing (ball diameter was machined to O.D. of bushing. We then had them rattle / not rattle after we had all the 93-95 shifters re-machined and installed the bushing on all of them.
We also machined an 81-88 short shifter to accept the 93-95 bushing, and had it rattle / not rattle in various cars we installed it in.
Most of the cars we were testing with had new trans mounts and good or new engine mounts — did not make any difference.
On a customers ’89 GTU we installed a Mazdatrix short shifter. The shifter did not rattle at all. The customer then replaced the transmission-the shifter now rattles.
On the owners’ ’86 GXL we installed a Mazdatrix short shifter and it rattled. We then installed a C’s shifter, and it rattled. This was the car we then machined the lower ball to take the nylon bushing – and it rattled. We tried MANY different types of oil and wheel bearing grease — it always rattled !!.
The one thing we found that made a BIG difference, was to be sure and have the oil level in the shift tower ABOVE the socket the lower ball goes into. The shifter is still in his car — the neat short shifting is worth the trade-off for the noise.
The odds are about 1 out of 3 ANY short shifter in YOUR car might rattle — if you are reluctant to accept those odds, then we would recommend you do NOT purchase a short shifter.