258 i6 jeep cj7 main seal leak!

[ShakenBake]

What is your guyses take on the main seal leak, on the i6 258 engine? Leave it, or fix it? It just leaks a little right now and I am contemplating wether to fix it or just leave it, can it get worse?

1981 jeep cj7 i6 258

Thanks

 

[Bounty__Hunter]

It will get worse. I'd fix it.

 

[greg92jeepxj]

Agree with Bounty_Hunter , the leak will eventually get worse . Replacing the seal is the only fix , additives are not the fix . I just replaced one on the same engine recently and will say it was worth the time and grime. If the jeep has a manual trans , the leak will soak the bell housing and get into the clutch facing as it did on mine . Won't affect an auto trans in that way but low oil pressure due to the leak is NOT a good thing . Spending money on adding oil is not the worst of it , low oil,pressure is bad news for any engine . Sorry , but it's got to be done . The seal isn't expensive and if your doing the job it's a lot easier than a later model jeep . Starter comes down and right side engine mount so the oil pan clears . I loosened all the main caps to allow the crankshaft to drop what little it does ( just a fraction of an inch ) so to make removal and reinstallation easier . Torque the bolts back on to specifications . Not a tough job but you will get an oil bath . Use permatex hi-tack or whatever is on the market today to stick the rail gaskets to the engine block and RTV to hold the front and rear pan seals in place . The oil pan will go right back up . The upper seal is what needs care upon reinstall but just hold it flush to the crankshaft surface as you start it into the cavity and keep it against the crank as it spins into place . It's recommended the top of the seal be lubed with dish washing liquid and the sealing surface ( seal lips ) with engine oil . Done several in my time on various engines and always works. Make certain the upper cavity is clear or. Reinstallation will be difficult . Nothing to fear , just follow instructions . The ols seal is removed with a punch . Just find where the hard , round wire end is and start tapping to loosen it . Once it moves , grab the other side with long nose pliers closest to the engine block and gently pull keeping the seal close to the crank for easier movement . The wire that you must tap with a punch will be nearest to the outer edge of e seal toward the block surface away from the crank . Make certain your on it . Scrape some of the rubber off the end of the seal if you can't see the round indentation in the rubber . That is where you'll place the punch

 

[greg92jeepxj]

When removing the upper seal . Use care and only use what force is necessary to remove it as you won't want to cause any unneeded damage to crank surface or seal cavity . Just concentrate on placing punch on the internal round wire and tap . You won't be able to tap too far but you'll be able to get it started and pull down against crank in circular motion to remove . That important to maintain that movement to getting to upper seal out and the new one in . As long as it's lubricated correctly all will go well. Seal the main cap ends as per manual instructions to prevent leaks . Use RTV on corners where main cap rubber seals meet rail gaskets meet to prevent leaks as well . After a successful reassembly , hit the showers , you'll need need , badly . It's a dirty job but once done right you'll be happy it's done .

 

[ShakenBake]

Ok, thanks for all the instructions, much appreciated, it just sucks that it is leaking because the dude that owned the jeep before me just replaced the main seal, I guess he just did a shitty job, or it's leaking from somewhere else.

 

[greg92jeepxj]

Your most welcome . Sorry it's got to be done again but at least not twice by you . That's what gets me upset , if I got to do something twice. Do wash down everywhere you can to find the origin of the leak to confirm . Would be nice if all that is leaking is the valve cover . If one isn't careful , it is possible to mess up a two piece rear main seal install . That is why I say it's best to do the extra work by loosening all the rear main caps and not just removing the last one where the rear main seal lives . That little bit that the crank drops seems to help even if we can't see any measurable drop. As long as the cavity is clear , the top of the top half of the seal is lubed with the soap and bottom with clean engine oil and the old seal taken out humanely , I see no reason for success . The only trick to install is starting it into the cavity . I don't remember using any of the "shoehorn" tricks on the 258 seal , I just held it upside down on the crank surface , lip seals toward front of engine and carefully worked it into the cavity . Properly lubed , it will go right in. Just keep it against the crank as you carefully work it with your fingers into the cavity. A punch to remove to old one , your fingers to install the new.
Btw , the punch shouldn't be big at all , the sturdy round metal half ring is about 3/16" or so like baling wire . Just place the punch toward the outer most end of the seal away from the crank . That is where the metal ring will be found. That is where most find their difficulty in the removal . Once you find the end to place the punch on , your on your way . Be cool with it , on,y strike the punch just hard enough to budge it and it will tap out. You can certainly try to get a straw of a penetrating oil can where the lip meets the crank and anywhere else to help wet the set for easier removal but remember , your the guy who's looking up at it ( drips) . Bad enough the jobs entails taking a " golden shower " . Don't mean that any wrong way , but that's what went through my mind when I kept wiping my head and face . My hair got the oil treatment . Allow engine to cool or it turns into a hot oil treatment.

 

[Bounty__Hunter]

Since the seal was replaced recently I'd make sure you're not building excess crankcase pressure, either from blowby or a clogged PCV system.

 

[69jeepcj]

Mine is leaking slowly as well, been for about a year or so now. That being said, I would fix it when you can. I had a rear main blow on a s-10 blazer once and the whole thing blew out leaving a big cloud of smoke and a engine with no oil, not good. lol

 

[ShakenBake]

Ok thanks