Why is one shifter bushing tight and one loose?
If you have bought a Garagistic Oval shifter bushing, round shifter bushing, or any shifter bushing kit, you may have noticed that one bushing fits perfect and the other side might appear "loose".
Here is the reason for it and why it will not affect the performance of your new shifter bushing installation:
The original Aluminum cast BMW Shifter carrier (the part this bushing gets pressed into) is a tapered hole. This is because in the making of a cast part (like your OEM shifter carrier), they need to be able to form a hole and have it release easily in mass production (hence the taper). Aluminum die casting with holes cannot be cast without that taper. When you look at your carrier housing, you will notice a split lines where the two halves meet. You will also notice that the part where your shifter bushings get pressed into is actually 2 different sizes.
Having said that we make our bushing to be universal to avoid assembly errors. (If the bushing was customized based on the taper and was accidentally interchanged, it's easy to permanently damage one bushing )
We maintain a nominal dimension so it can be interchanged. Though it seems one time tight fit on one end and easy fit on the other end, this will not only make it easy on the assembly but will not affect the performance of the shifter itself.
One solution would be to make 2 different bushings (one for each side). This will increase cost for customers on a part that is meant to be an affordable modification. It can also make it possible to install incorrectly. This is not a feasible solution.
The other solution (what other competitors do), is to make bushing bigger to make it fit both sides tight. In that process, one bushing still fits better than the other. The only difference is that the one that was "smaller" is not a super tight fit and will push on the pinhole making it impossible to push bitch clip though. This is not a good solution but has been an industry standard for these parts. It means you will not find out why the "bitch clip" got its name until you are in the middle of installation under your car. Turning your simple upgrade into a nightmare job.
This will not affect performance because the lip on the bushing stops all side to side play when installing on the transmission (where the bitch clip goes through). Once installed, it is tight so side to side play is eliminated. The center hole where the clip goes through does the rest of the work. It's very accurate for the bitch clip that goes through it. So that eliminates forward and back play. Between both of those concepts, all play is eliminated so one bushing being tighter then the other makes no difference!
Too long didn't read cliff notes:
OEM shifter carriers are originally Aluminum die casting and the hole cannot be cast without that taper in the shifter hole area (where the bushing goes in).
We cannot make 2 different size bushings for this. Our shifter bushings are be universal to avoid assembly errors and keep costs FOR YOU low. (If the bushing was customized based on the taper and was accidentally interchanged, its easy to permanently damage one bushing )
Once installed: 1 tight bushing and 1 "loose" bushings will still eliminate front and side to side play as originally promised. Meaning the part will work as intended and you will be very pleased with your shifter play eliminated!
- Competitors make both bushings oversized making them a press fit which will shrink the middle hole making it impossible to install pin after that without drill bushing. Its how the clip got its famous name of "bitch clip".