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Mod | | | Forums66 Topics128,050 Posts1,055,643 Members48,426 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Jun 2016 Posts: 102 Shop Shark | | Shop Shark Joined: Jun 2016 Posts: 102 | 1948 1/2 Ton Truck with a '62 235ci engine. I have a slow oil leak in the very front of the block. I've checked the oil pan carefully and it's not coming from there. I'm pretty sure it is coming out of the bottom of the Timing Chain cover. What concerns me about that is, there are 2 bolts at the very bottom of the timing chain cover that appear to be bolted from the inside (have to remove the oil pan to get access to them??) I just see 2 threaded bolt studs, with no nuts, so I assume the bolt heads are inside the bottom of engine, accessible when you remove the oil pan.
I would characterize the leak as 1-3 drops per day, so it's very slow. They've only showed up now that I've been running the motor. It had been sitting for 2 years without running and it was not leaking then.
Question: How involved is it in getting the timing chain cover off to replace the gasket? Right now I am in a frame off restoration, so it's just my motor sitting on top of the chassis, with radiator, fan in place. My oil pan is not leaking and so I'm reticent to take it off (if that is required?), in order to get to the timing chain cover removed. Cause then I'll have to replace the oil pan gasket too, and doing that laying on the ground looks like a pain in the arse....Please help.
Last edited by BobbyAlton; 09/20/2017 12:22 AM.
| | | | | Joined: Feb 2004 Posts: 29,767 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,767 | If it were 1 to 3 drops a minute I'd be concerned. Getting a stovebolt to stop leaking is easy- - - - -drain all the oil out of it and wait about a year for the residual oil to quit seeping out. A stovebolt that runs is going to leak- - - - -get used to it. Ditto for Detriot Diesels and Harley Davidsons! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
| | | | | Joined: Jun 2016 Posts: 102 Shop Shark | | Shop Shark Joined: Jun 2016 Posts: 102 | Thank you Tim & Chris, the instructions and photos are very helpful. I guess it will have to be done, since the body is not installed (haven't worked on it yet) this would be the time to do it.
Any tips on proper oil pan gasket installation? I'll be doing it laying on ground (wish I could do it with the motor inverted on a stand) but I don't want to take the engine off again b/c getting the transmission, fuel lines and everything else hooked up really took some time earlier this year. Be that as it may, concerned that the oil pan gasket might not stick in place nice and flat before I can get the pan back on there while I'm laying on the ground....
Last edited by BobbyAlton; 09/20/2017 12:50 AM.
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Place a disposable diaper under it (and under the u-joint housing, and under the rear end, and under the rear-engine clutch housing (rear engine/crankshaft seal) while you are at it - if/as needed).
It it ain't leaking somewhere, it is out of oil. | | | | | Joined: Jun 2016 Posts: 102 Shop Shark | | Shop Shark Joined: Jun 2016 Posts: 102 | Thanks Jerry, that is re-assuring. Yeah, I worry going in too much on the gear cover - I will end up with a leak somewhere else. | | | | | Joined: Jul 2010 Posts: 592 Shop Shark | | Shop Shark Joined: Jul 2010 Posts: 592 | Bobby, the two bolts that pass through from the inside should be held in place with a keeper that has tabs bent up to hold the heads in place. Because of the keepers, you might able to snug them up a bit. Not too snug...I think 7 foot pounds is the spec...so be gentle. Remember, you're just snugging to a gasket with some give, not metal to metal. Might help, might not.
Matt | | | | | Joined: Jun 2016 Posts: 102 Shop Shark | | Shop Shark Joined: Jun 2016 Posts: 102 | Ha! Yep - how did you know? I removed the driveshaft this winter, removed the rear diff cover, took off both axles. Cleaned up the diff real good, put a new gasket on front & rear of it (gasket along with permatex silicone) sealed everything back up tight. It was good for a few months, now it's dripping again (and I haven't even driven it yet) I'd say the diff is leaking about 1-2 drops per week, very low amount, but darn it all.
Last edited by BobbyAlton; 09/20/2017 1:02 AM.
| | | | | Joined: Mar 2010 Posts: 10,272 Renaissance Man | | Renaissance Man Joined: Mar 2010 Posts: 10,272 | Here is why I am with Jerry on this one. If you think it is difficult to seal a timing gear cover, wait until you try to get an oil pan to seal while lying on your back. I would wait until I had a more pressing reason to take off the oil pan than a very normal minor leak at the timing gear cover. Carl
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
| | | | | Joined: Jun 2016 Posts: 102 Shop Shark | | Shop Shark Joined: Jun 2016 Posts: 102 | I was hoping to hear that Carl, music to my ears. I don't even think it's 1-3 drops a day, every day, just for a day or 2 after motor has been running.
Guessing it wouldn't make any sense to make a phillips head slot on the face of 2 lower bolts, to turn them and snug them up? (sounds like they probably have those keeper tabs on the inside on the bolt heads?) | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | When you do take the pan off, tap those two bolt holes-already the correct size-so you can remove the timing cover by undoing those bolts from the outside.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | . . . but, darn it all . . .
hmmm, . . . . a pipe dream: stopping all leaks on an original stovebolt drive train.
Let's hear from anyone who has an original stovebolt drivetrain with no leaks (tell us how many miles it has been driven with no leaks/drips).
The 1954 Hydra-Matic 3104 that is an almost perfectly restored drivetrain, and is now sitting in my garage, is not yet leaking; however, it has not yet been driven. | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | If the leak is coming from the front crankshaft seal, which is more common, you can replace it without removing the cover. | | | | | Joined: Mar 2010 Posts: 10,272 Renaissance Man | | Renaissance Man Joined: Mar 2010 Posts: 10,272 | Look at the bright side. Your oil squirter if spraying oil on your timing gears like it should. Otherwise the cover wouldn't be leaking.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 |  Amen | | |
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