The Diamante has an odd issue where the vehicle will not shift gears correctly which an extremely dangerous issue for drivers. The information board shows the transaction rapidly switching from neutral to drive excessively. I have had multiple mechanic shops look into this issue from transmission specialists, to electrical specialist and have had no positive results.

- Moreno Valley, CA, USA

The main issue seems to be a manufacturing defect in the wave/cushion spring located in the transmission. Mitsubishi has designed the wave spring as a fragile two coil piece which has been known to repeatedly break causing catastrophic failure in the transmission. This in turn poses a threat on the driver and passengers. When this wave spring breaks, actual pieces of the wave spring make it through Mitsubishi also faulty transmission filter and lodge themselves in the pump gear, causing the gear to actually break. After the pump gear has been broken inside the transmission, all forward and reverse gears immediately stop function and in most instances the vehicle shuts off. This could result in potential harm or even death of the driver and/or passenger as the vehicle loses all moving power which can cause an accident with other vehicles on the road. Mitsubishi has recently created an updated version of the wave spring without issuing a recall, which now is a one piece instead of the coil setup and has a less chance of breaking.this update was discovered after they I had my vehicle in a transmission shop with a hefty bill to pay ($3,700) even though it was Mitsubishi fault for engineering a faulty part in their transmission. All one person would need to find out about this issue is search the internet with the transmission code (F4A51) and this issue is well documented, even researched by transmission digest (a specialty magazine). Not only is this a large inconvenience, it is also a hazard to ones life. Mitsubishi should recall all vehicles which contain the F4A51 automatic transmission to perform the wave spring and filter update or reimburse those, like myself, who have already had it done at my cost.

- Richmond, VA, USA