So the wife and I are currently tackling leaks on our 235. The leaking water pump gasket and front main are the major causes of the leaks. I've already replaced the valve cover gasket, the side cover seeps a little, as does the oil filter lines which will get replaced. We're dropping the oil pan as well and will do the timing cover mod while in there. Rear area of the engine is wet, but doesn't seem excessive, it does have the odd drip from the drain plug area. Now, if it still has the rope style rear main, would you attempt to replace it, or leave it?? It's a fel-pro kit that we have, I've read that best gaskets are the rear main seals to get, but we're not going to wait at this point for one to show up if we were to order it.
Looks like your on that slippery slope........where your at the point ..........where it’s almost easier to pull the engine to completely clean, disassemble, fix all the leaks, paint the engine then detail the engine bay.............and the list grows and grows where engine rebuild starts.
If it were me, I would order and wait for the Best Gasket main seal to arrive before I took the oil pan off. Properly sealing an oil pan is difficult enough to do once, let alone twice. If you plan on doing the rear main seal at some other time in the future, you will need to take the oil pan off again, clean the sealant off, and reseal it.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
Unfortunately we don’t have time to dig too deep at the moment. We’re just cleaning it up as best we can to have it safetied. Then we’ll keep picking away at small things over the summer, but still use it for grocery runs, etc. Any bigger items we will order over the summer and be left till next winter.
I would not waste time replacing a rope type seal with a non Best gasket. They are far superior to the others. If you have a neoprene seal they are easier to replace.
Assuming your engine is a babbitt baby, I'd check the clearances and adjust as required. I checked mine when I did my rear rope style main seal. It was in specs, but had I removed shims taking it to the minimum I believe I'd have a better seal on the rear main. It is about 80% leak free. Much better than before I replace the old seal, just not leak free.
I don’t think it is, but I could be wrong. Next winter we are planning a trans swap of some sort if all goes well, so I’ll look at the seal then - if it’s still leaking.
Thanks for the info. Dropped the pan last night and found a nice amount of sludge in the bottom as the drain plug doesn't sit as low as it should. Something I haven't seen before is all the white paste under the sludge. Would that be from leaded gas back in the day, or more indicative of being a babbitt engine?
My guess is that white paste is more "sludge" of different consistency/composition/color/age.
not due to leaded gas not due to babbitted rods
due to - non-detergent oil, and - infrequent oil changes ,and - oil not being drained soon after driving, when warm and still holding "gunk" in suspension
Get one of the above referenced GM rope seals. The Best seal that is currently sold is the best seal currently sold, lol. It is not however, at least in my view, the best seal to use. The original seals contained an asbestos component to them. The current Best seal is a graphite fiberglass deal. The older seals seem to work better at maintaining their shape around the crank and thus the seal then do the newer rope seals so you would want to try to find a GM or felpro (has to be one from at least the 70s and earlier, before the asbestos was removed).
