While driving my 83 245DL yesterday I filled up with gas, pulled out on the road, got up to speed and pushed OD button and it didn't engage. Drove the car home at about 40MPH, left it till this morning. Started it up this morning took off down the road OD worked till I got a few miles down the road and had to stop, didn't work again. Got home and began inspecting. OD relay working, just rewired the switch and solenoid last weekend and still seems OK. 4th gear switch works properly. In the garage I turned key to run position put it in 4th gear pushed OD botton, relay picked and I could hear the solenoid activate as usual. My question is "Will repacing the O rings on the solenoid fix this or is there something bigger in my weekend plans like an OD rebuild?".