1968 Evinrude 40HP Selectric Shift Won't hold in gear

[vandenburgh]

The springs/hubs in this gearcase are extremely sensitive to the viscosity of the oil, which is why you must use the right lube (I use sierra brand type c in my electric shift) Seems possible that if you had used wrong oil, then drained and refilled, you may still had too much residual old oil left as it all doesn't drain out. As pointed out by others, any water in oil is an issue. Also, any grit in the gearcase can cause slippage. perhaps flushing with correct lube a couple few times might be worth a try or others may have a solvent to recommend. If your magnets check out, would highly suggest trying flushing before opening her up.

For what it is worth, i had slipping problem too and ultimately pulled it apart and rebuilt - my issue was it just needed a good cleaning, also found some bad bearings that I replaced, hubs and springs I disassembled, cleaned and put back in. Worked fine after rebuild - point is you may not need any pricey parts even if it comes to needing to rebuild.