1984-1988 C4 4+3 Transmission Overdrive Unit Pan Gasket
If your 1984-1988 Doug Nash equipped Corvette "marks its territory" try our custom gasket, more effective than OE recommended RTV Sealant.
Approximate Gasket Overall Dimensions: 10-3/4" x 7-1/8" x 1/32"
Also available in our handy filter and gasket kit.
MADE IN THE USA
During the critical early years of Corvette Racing, the 4+3 was a leading edge advantage for Corvette winning the 1984, 1985, 1986, 1987, 1988 SCCA Showroom Stock Endurance Series Championships.
RPO MM4 Production Quantities By Year:
- 1984 RPO MM4 6,443
- 1985 RPO MM4 9,576
- 1986 RPO MM4 6,835
- 1987 RPO MM4 4,298
- 1988 RPO MM4 4,282
Tech Tip: 4+3 Transmission - Oil Change Procedure For 1984-1988 Overdrive Units
1. Raise car on hoist and remove the 12 bolts holding the oil pan on the overdrive unit.
2. Remove the oil filter and always replace it with a new one. Lubricate the pickup tube and new filter grommet with Dextron II ATF before installing, making sure the grommet is not pushed into the body of the filter.
3. Clean the oil pan and dry thoroughly.
4. Place the magnet in the proper location.
5. Make sure the overdrive housing edge is clean and dry.
6. Apply a bead of R.T.V. to the oil pan's flange.
7. Place pan into position, and reinstall all 12 bolts, hand tight. Then tighten all bolts just beyond hand tight. Then alternate tightening bolts to 8 to N/M or 6-8 foot-pounds.
8. Remove square-headed filler plug on the left side of the overdrive unit. Note: The steel plug is going into an aluminum case; so, a quick counter clockwise movement will help loosen the plug.
9. Fill the overdrive unit Automatic Transmission Oil until oil runs out of filler hole. Before reinstalling the fill plug, coat the threads with a anti-siege compound.
10. If the car is a convertible, reinstall the X-member.
11. Drive car and retest overdrive unit after oil is up to normal operating temperature.
12. After test drive recheck the transmission oil. Raise car on hoist and remove filler plug. The oil may be so low, if so, refill and retest overdrive unit.
If you regularly drive your 4+3 transmission car, change the overdrive unit's oil at least once a year. If you drive over 25,00 miles a year and use the overdrive a lot, it may be beneficial to change the oil sooner.
Keeping a good clean oil in the overdrive unit is probably the most important thing you can do to keep a good operating overdrive unit.
Keeping the TPS and clutch switches adjusted properly will help eliminate future failures of the overdrive unit's operation.
Also known under these part numbers: (For reference only)