OK, I pulled my flywheel dust cover today because I am so tired of wiping up Thunder's mess. We drip/dump roughly 2 oz oil engine oil in a 100 mile trip, and drip whenever the truck sits. i know Thunder likes to mark his territory, but he gradually gets "better" at it. How much dripping at the rear engine seal do you other AD enthusiasts endure before you go back in and replace the seal? This engine has been rebuilt in 2001, running since 2002, has roughly 8,000 new miles, but sits for weeks at a time in my garage. The big drip falls from dead center of the engine in front of the flywheel, there is also a drop of oil on the clutch/shift yolk. Any advise will be appreciated. Jim
Jim, I have a drip pan under mine which will fill in about two weeks that is sitting in the drive way with an incline from the street. The pan has a ½ inch lip and is about 24 in.x36in. This Drives me crazy, has ruined the new drive way (looking at it) The engine is a 1956 235 which was in the truck when I picked it up in Rapid city, S.D... Was about ready to tackle that when the 6/12 conversion took a right turn. Thanks for bring that up. Charles (ccharr) '48 3804 registered as a '47 or so the vin# indicates
Don't automatically assume that it's the rear seal. Gravity will cause oil to gravitate to the lowest part of your engine (flywheel cover). Check first to see if there is any signs of leakage anywhere else. Also check to see if there if oil on the front of the flywheel. That's normally a sign that it's probably the rear seal.
If nothing else- consider the frequent oil addition as a very slow oil change. You keep sticking fresh oil in, just do the filter and you're in.
Rear Main Seal Leaks Well ; It's a rope seal (" dog turd ") right ? . Assuming the main bearing isn't too terribly loose it's entirely possible that when the rope was inserted the ends were trimmed flush with the block and bearing cap , IIRC some shop manuals say to do this but then there's no pre-load on the rope so it relaxes and doesn't seal well . I always leave a little bit sticking out so when you torque up the bearing cap the seal is squashed into place , this staunches the leaks *BUT* if you leave too much sticking out it can get pinched between the cap and the block and then you'll break off a corner of the bearing cap , a _very_ bad thing .
"Dog Turd" indeed! Here's the real question! OK, I've put in a couple of rear seals before, but it was when I had the engine out of the truck or car. The real question is: Is it possible to replace the rear seal with the engine in the truck? I'm thinking that that would be a major job. Thoughts, anyone? And if it's possible, what is the best part to do it. Rubber or rope? Inquiring minds need to know!
Ken: I figured an old expert like you would have a Slick Willie in his tool kit. No,not that Slick Willie. I'm referring to the one you use to change rear main seals without dropping the crank.
No Ken the real question is do you have access to a lift or not. If you have a lift I would say leave the engine in and pull the tranny out and do it in the vehicle. I do cars this way all the time. If no lift then it depends on how much time you want to spend lying on you back or just pull the engine out. As far as the part, well you all know I don't restore the originals so we'll leave that to someone more qualified than I.
I thought "Slick Willie's" was a pool hall in Houston! I know you could do it, Bill, but what about us pool sharks? OK, here's the deal. We meet at the Slick Willies on FM 1960, and if I beat you, we drive to Port Arthur and you replace the rear seal in Thunder54's! If I lose, we drive to Port Arthur and you tell me how to replace the rear seal in Thunder54's truck! Deal?
Boy, this is getting pretty heavy there guys!! mine leaks a little, like Nate said. I'm just glad it ain't brain fluid! It's not enough between oil changes that i have to worry about it. Drive the old bitty and enjoy her!
That's what they make "kitty litter" for! It's cheaper than oil-sorb, plus they make it in pine scent now!
Rear Main Seal Replacement Yes you can change the seal in situ , the typ of seal dictates the tool needed , I'm betting it's a rope seal and so will need a " Sneaky Pete " ~ this is a woven wire tube thing like a Chinese Finger trap toy , it has a T handle on one end , you loop the tool over the crank and then you insert one end of the new rope seal and give it a tug , the woven wire tube collapses and is used to drag the new seal up and over the crankshaft . NAPA and others sell it , I see them in pawn shops amongst the crappy tools as few know what the heck it is anymore . Some caveats apply : Getting the old rope out is (NOTE : not can be) a real PITA and takes time & patience , I use bent up coat hanger to dig it out , one must be very careful to not scratch the upper bearing nor the polished part of the crank where the seal rides , the old rope must be 100 % removed , it'll come out in thousands of bits and one or two long pieces . There's no need to remove the tranny ~ just loosen all the main bearing caps then step on the clutch , the crank will drop maybe .010" and that's enough working clearance but remember to have the clutch pedal in when you're re-torquing the mains ! . I like to roll the new seal in my fingers untill it's slightly egg shaped as it'll slide in easier thata way . YMMV , Caveat Emptor Batteries not included Do not taunt Happy Fun Ball ! . Only one cuppa yet so don't be upset if I forgot something important .
Trip to NAPA I'm on my way to the NAPA store now! My next door neighbor owns the nicest pool table in south Jefferson County, you boys can play for free, and you'll already be in Port Arthur. Do I get the new rubber seal or the dog turd? I will get a sneaky pete/slick willie because I want one. My bride suggests I just continue to use the portable drip pan, or as she calls it, the "Chopin" (get it; Show Pan). Thunder does the 'show pan and shine'! Jim
Seal & Gasket P/N's Well ; I'd said you're stuck wit the rope seal due to the engine's design but looking in my NAPA Victor gasket catalog under 1953 ~ 1962 Chevrolet 235 it says " Rope Seal # JV650 Moulded Rubber Seal # JV737 Oil Pan gasket # OS31116 So it appears you have choices ~ I'd buy both to save a return trip and see if the Moulded Rubber one works....
mia culpa Well, I have continued to monitor my oil usage. seems i am losing more tranny oil from my sm420 than engine oil, and all of it runs out from the little hole in the flywheel dust pan. I am ready to pull the tranny (once again). I may need to recruit Andy here. Then I decide to read my 54 truck shop manual once again. Transmission lubricant leaks, front pilot shaft, check oil slinger nut to make sure it's tight, check transmission fill level (1/2" below plug hole cold, level to plug hole hot). Dang! I have been overfilling my tranny cold for a long time. Running perfectly good oil out of my perfectly good truck because i didn't take into account expanding liquid volume. Sorry Ken and Bill, looks like we won't be replacing my rear engine seal for a while yet, but I would like a rain check on your offer. I'm also pretty good at topping off my sm420 while lying on my back through that tiny hole above the U joint. I even fashioned a little hand pump for this duty. Boy Howdy, did I learn something this weekend! Happy New Year. Jim
All's Well That Ends Well...... Don'cha just LOVE simple solutions ? I sure do ! I hope by now you've run down and instaled a 1/2" NPT magnetic tranny drain plug . I'm also using synthetic gear oil , it helps shifting greatly and if it stops wear dead like synthetic engine oil does , it'll be a great addition to your tranny .
