A Is your car fitted with the standard manual transmission or the sequential manual transmission? Toyota had problems with its sequential unit, but the standard 5-speed does not appear to be problematic. You also did not say what type of failure the transmission experienced. Bearing failure is usually preceded by increasingly loud "whining" noises, while synchronizer or gear failure usually manifests itself as grinding, failure to go into a gear or popping out of gear.
My first thought was to focus on the lighter-weight lubricants used in modern manual transmissions. Typically, ATF (automatic transmission fluid) is the lubricant of choice in today's stick-shift cars.
But that's not the case with your MR2. Toyota calls for GL4 or GL5 75W-90 gear oil, depending on whether the transmission is equipped with a limited slip differential or not. The heavier gear oil is used because the unit is a transaxle assembly that incorporates the transmission and differential in a single case.
The only thing I noted when checking the ALLDATA automotive database is the difference between maintenance requirements between "normal" service and "severe" service. No transaxle fluid changes for the life of the car are suggested under normal conditions. However, Toyota does recommend fluid changes every 30,000 miles under severe service conditions. I've always maintained that the vast majority of motorists operate their vehicles under severe conditions the majority of time.
Q In May, I awoke at 5 a.m. to a loud boom followed by my neighbor pounding on my door. My son's car, a 2001 Chrysler Concorde that was parked in the driveway, was engulfed in flames under the hood. It was a total loss. The local fire chief believed the fire started on the left side, as the battery was melted and the front left tire was gone. Any thoughts as to what may have started the fire? The car had a remote start that would easily kick on if the button on the key fob was accidentally pushed while in a pocket.
A I've done a number of vehicle autopsies over the years, including several vehicles destroyed by fire. While I'm no expert on fires, the melted battery would appear to indicate your vehicle suffered some type of dead short between the battery and chassis. Did the vehicle have any aftermarket audio equipment installed? I've seen several fires that originated with a wiring issue involving aftermarket equipment.
Q I have a 1995 Nissan pickup with 224,000 miles, mostly on the highway. Since about 150,000 miles, I've noticed a moaning sound from the gas tank area when the weather is warm. I purchased a new gas cap but it still moans in warm weather. If I release the gas cap slightly, the moaning slows down or stops. No one seems to be able to tell me the cause and how to fix it. Can you?
A The primary suspect is the charcoal canister purge valve. This valve is electrically controlled by the engine management computer to open and vent fuel vapors stored in the canister into the induction system after the engine is started. It may be that this valve is no longer working, thus the fuel tank builds excessive pressure because the vapors are not being vented. The ALLDATA database pulled up a Nissan service bulletin addressing this type of noise that suggested installing the updated purge control valve, hoses and mounting bracket from the 1997 model year truck.
At least check the valve, located next to the air cleaner, to see if it is operating properly.