My fluid questions pertain to a '49 GMC 3/4 ton with a '54 Chevy 235 engine. The 4-speed tranny and driveshaft are the "open driveline" type, so I'm thinking they are the original GMC components. My fluid questions... The original "Owners & Drivers Manual" I found under the seat specifies 50W motor oil for the 4-speed tranny, but I note in other posts with lube questions that several regulars in this forum recommend 90W gear lube. I've already drained and refilled the tranny with 50W engine oil... should I drain again and go to 90W gear lube? Crankcase oil capacity question... my 235 does not have an oil filter. I don't have the specs for my engine, but when I changed the oil I found that four (4) quarts brought the oil level to the full mark on the dipstick. However, I found several archived posts that indicate the oil capacity for a '54 235 is five (5) quarts. Perhaps the five (5)quart capacity is only for 235's with the oil filter?
RE: Two Fluid Questions... Crankcas Mike- I can't answer the question about your tans, but 50w sounds pretty light. If you can't find a definate answer here, check over at the stovebolt page. Click www.stovebolt.com As far as the oil capacity of a 235, they take 5 quarts. 6 quarts with an oil filter. The dipstick or dipstick tube could have been replaced or modified at some time in the past, causing a false reading. Good luck with it and keep us posted on your progress.
RE: Two Fluid Questions... Crankcas What Tim said ~ get it good and hot and drain the tranny & refill with good 90W or 85W-90 but get that thin crap _out_ ASAP ! . Fill the engine wth 6 quarts then make a new full mark on the dipstick , then take it around some junkyards untill you find a correct one , may not be from a 235 though.... I had this same problem when I bought my '49 , wrong dipstick that indicated 4 quarts was full . -Nate
RE: Two Fluid Questions... Crankcas Tim & Nate - Thanks for the responses. I'll drain the tranny and refill with the 85-90W gear lube. Nate - clarification on the crankcast quantity... my 235 does NOT have an oil filter. Tim says quantity should be 5 qts without filter, but you said fill it to 6 quarts and remark dipstick.
RE: Crankcase Level OK... Four (4) quarts brings her right to the "Full" mark on the DS so I'll put in five (5) quarts and when the level drops to "Full" I'll know it's time to add a quart... or just do a change. Thanks!
