Rear Main leakage (1 Viewer)

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Joined
Mar 31, 2005
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Gentlemen,
Doing a search on 'rear main seal leakage' has brought a few questions to my mind. I have wondered about others experience with the leakage of oil, which appears to be from the rear main seal. I consistently, have a noticeable buildup on the bottom of my engine/trans. However, I do not have enough to actually drip on to the ground below. My truck does not require adding oil in between usual OCI. Would I see contamination in the trans fluid? Should I worry, or be doing something? I saw something about PCV replacement maybe helping that?
TIA

Chris

94FZJ80 135K 2.5OME 285 Cooper ATR Pin 7 CDL
 
No one has attempted to answer you, so I will try. The oil is either from the Pan arch or the rear main. To get the best diagnosis you would need to climb under the truck and remove the black plasitc thing and look with a mirror at the rear main seal and crank to see if you have a pan arch leak or rear main. When it gets too much for you to bear (the leak) then it is time to fix it. Unless you hate leaks on your truck(major pet peve here). So you may need to look or make a choice. later powderpig
 
Most likely the pan arch, requires lifting the engine clear of the front mounts to remove and re-seal the pans. Plan on 2 full days if you want to attempt it yourself or a full day's shop labor. I have done one and would not want to "flat-back" it. It could possibly be the rear main, that requires removal of the transmission/transfercase. Similar times apply and another "flat-back" bitch.
 
Before you dive in to replace the seal, try changing your oil to one of the "high mileage oils in 10W-40 weight. They are a synthetic blend and have a seal sweller additive. I had a leakage similar to what you describe and after a couple thousand miles using Mobil "high mileage" oil, it seems to have stopped completely.

Bob
 
Just an academic question - can you pull the entire engine/trans/xfer case as a unit for some of this servicing, the same way you can on earlier 'cruisers? Or is there a structural reason you cannot do this with an '80 series. I'm not suggesting it's easy, or ideal - just wondered if it is possible.

Steve
 
Yes, it can be done. In fact that is how the FSM shows it done.
 
Mrsalty, i believe you and i have a common leak. Mine is just as yours, and doesn't accumulate enough to drip to the driveway. So, for now i'm just leaving it alone.
 
Gentlemen,
Thanks for the information. I have no idea what the 'pan arch' is, but I do know how to use the search function. Leaks only bother me when I know it will cause a problem. Sounds as if the only problem is the oil level dropping??? I would need a better reason than that to go through the 'flat-back bitch'....hey, wasn't that the name of a DVD I saw........nevermind! Anyway, I am running Valv 10 30. I had problems using a synthetic in my F150, after switching from dyno. Problems as in MAJOR oil consumption. Anyone have experience running synthetic in their higher mileage FZ (maybe that should also be a search function question, but I am lazy)? Aside from the oil residue, the vehicle runs solid. I have little consumption between OCI, and everything seems to be running exactly as it should. Thanks again for the replies, really appreciate it. 'Powderpig', maybe I can bribe you with some #6's to give me a hand if this turns out to be a bigger problem than I can handle. Thanks again.

Chris

94FZJ80 135K 2.5OME 285 Cooper ATR Pin 7 CDL
 
Chris, I switched from Valvoine dino 10-30 to Mobil 1 5-40 i think and haven't had any problems. I did the switch at around 130,000 miles and now have 165,000.
 
concretejungle said:
Chris, I switched from Valvoine dino 10-30 to Mobil 1 5-40 i think and haven't had any problems. I did the switch at around 130,000 miles and now have 165,000.
Mobil 1 5-40? What do you pay a quart, and where? What filter are you currently running?
TIA
Chris
 
mrsalty said:
Mobil 1 5-40? What do you pay a quart, and where? What filter are you currently running?
TIA
Chris

It's cheap at Walmart. I buy the 5 quart jugs for around $20 and then get three more regular quarts to equal a total of 8 quarts. Then i go to Oreilly's or Napa and buy either the wix or Napa gold (made by wix) oil filter. With the synthetic oil in, i will run it for 7 - 10,000 miles before the next change and usually will require the addition of one quart between changes.
 
mrsalty said:
Anyone have experience running synthetic in their higher mileage FZ (maybe that should also be a search function question, but I am lazy)?

94FZJ80 135K 2.5OME 285 Cooper ATR Pin 7 CDL
Well do you have another Cruiser w/high mileage? 'Cause 135k is not high mileage for a 1FZ :doh:

I had 175k on wine when I swithced to M1, it continued to have consumption issues (it had them before), then I switched to Rotella Synthetic 15w-40 (or is it 5w-40?) which was available at Wal-mart for ~$12/gallon. My consumption went down considerably. :)
 
firetruck41 said:
Well do you have another Cruiser w/high mileage? 'Cause 135k is not high mileage for a 1FZ :doh:

Yeah, did you see that I owned an F150.......LOL
I will take a look at Sam's club when I am there next. I guess I am worried that replacing the rear main or pan arch will have to wait for an engine rebuild, 250-300K?
Thanks
 

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