Why can't CD's for replacement superdrive be inserted like original?

I just replaced the Superdrive with a UJ-875. I followed the instructions in your repair manual and found them be very accurate and helpful. The replacement process went very smoothly.

The new drive works just fine with the exception of one problem. The old drive required me to insert a CD or DVD about 3/4 of the way into the drive and then it would be mechanically pulled in the rest of the way. However the new drive will not mechanically pull the CD or DVD in until I push the CD flush with the bezel and then I have to use a thin device such as a letter opener to push the CD inside of the bezel about another 1/4 of an inch before it is mechanically pulled in the rest of the way into the drive.

Again the new drive works fine, and ejects just fine. When a CD or DVD is ejected it gets ejected about 1/2 way out of the bezel. The only problem lies with inserting CD's or DVD's into the drive.

Is there a way to adjust when to trigger a CD or DVD to be mechanically pulled into the drive?

Thank You.