Oil seepage...is it a problem? (1 Viewer)

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My 1997 LX (113K) received great inspection reports from both Toyota and my mechanic. Both listed only one issue. The seal that connects the back of the engine and the front of the tranny is leaking. Toyota said "it's sweating" and isn't a big deal. My mechanic said it looks a bit wet and we should clean it off good then watch it. He thinks if we need to replace it the tranny, driveshaft and t-case all come out.

I couldn't search because I don't know what seal this is. Is this a big deal? If we replace it does the tranny and t-case come out as one unit?
 
It's probably the rear oil pan arch and not the rear main. Re-sealing the arch requires removing both oil pans and lifting the engine up off the front mounts a couple inches (which requires removing the fan and clutch so you don't break the shroud) so that the upper pan can clear a frame crossmember.

If it is the rear main, the transmission and transfer need to come out and they come out in one piece.
 
cruiserdan said:
It's probably the rear oil pan arch and not the rear main. Re-sealing the arch requires removing both oil pans and lifting the engine up off the front mounts a couple inches (which requires removing the fan and clutch so you don't break the shroud) so that the upper pan can clear a frame crossmember.

If it is the rear main, the transmission and transfer need to come out and they come out in one piece.

Nice heads up. Thanks. I'll clean it off well and see where and how quickly it comes back. Is this common Dan?
 
Yes, the pan arch is quite common. I don't think I would worry too much about it til it starts to make a mess in the driveway. Do watch your oil level though....;)
 
To bring back your old argument, just another reason why the 80 is superior to the 100: built in underbody rust protection!!! :flipoff2:
 
turbocruiser said:
To bring back your old argument, just another reason why the 80 is superior to the 100: built in underbody rust protection!!! :flipoff2:

Now that's funny!

My mechanic said that sometimes you can't tell which is leaking until you get it apart? Pan Arch vs Main?
 
ShottsUZJ100 said:
My mechanic said that sometimes you can't tell which is leaking until you get it apart? Pan Arch vs Main?

Yes, it is difficult IMO to definitively tell which one is leaking. The rear main seal is housed inside the retainer arch. The bottom of the retainer arch (which is only about a 1/2" thick) seats and seals against the upper oil pan. So the source of the leak, be it the rear main seal or pan arch seal is within a 1/2" of each other. As mentioned, clean the area good through the port hole, take a small mirror, place it against the flywheel and shine a flashlight on the mirror to view up at the rear main, pan arch area.

Either way this is a pretty big job, so if it's not leaking enough to drive you crazy, then I'd leave it be.

:beer:
Rookie2
 
ShottsUZJ100 said:
Oil seepage...is it a problem?

Not for me, I have no problem with YOUR truck leaking! :bounce: :popcorn:

Just don't park that portable oil slick in my driveway!:D
 
Tools R Us said:
Not for me, I have no problem with YOUR truck leaking! :bounce: :popcorn:

Just don't park that portable oil slick in my driveway!:D

Watch it Kev. I might do by a Discovery II and embarrass you off road! :D
 
ShottsUZJ100 said:
Watch it Kev. I might do by a Discovery II and embarrass you off road! :D

Impossible, I have way to much practice embarrassing myself offroad!:D

I had you pegged as more of a LR3 guy!
 
I have the same seepage problem. Mine also builds up on the tranny and then sweats one or two drops onto the garage floor every two days or so.

Dan, excuse my ignorance, but when you say the "rear oil pan arch," is that the lowest hanging pan where the drain plug is located? From looking at my oil seepage situation, it looks like the RTV seal on that pan was not applied very well. Can you just drop that pan, clean it, and reapply RTV to see if that corrects the problem?
 
cruiserdan said:
It's probably the rear oil pan arch and not the rear main. Re-sealing the arch requires removing both oil pans and lifting the engine up off the front mounts a couple inches (which requires removing the fan and clutch so you don't break the shroud) so that the upper pan can clear a frame crossmember.

If it is the rear main, the transmission and transfer need to come out and they come out in one piece.


After reading this, I checked out my slight oil leak and sure enough, it's the rear arch seal :frown: but not my main seal :D Someday when I'm snowed in the house and it's -20 deg outside, I'll fix it with some Right Stuff.
 
UPDATE AND QUESTION: This leak is a "leaK" and not a "sweat" like I was told. I will get fixed soon. Toyota said it was the main and not the arch? We'll see.
MEANWHILE....today, as I pulled out onto the main street by my house (vehicle not quite warmed up), when I stepped on the gas the thing hesitated then away it went. It sounded a felt like a manual where you didn't let the clutch out enough so it only "half went" until you let it out all the way. After that ONE incident all was OK the rest of the 30-minute trip. :confused:

Could this be related to the leak?
 
Last edited:
ShottsUZJ100 said:
Could this be related to the leak?
A leak will not cause any problems, low oil will cause problems. You could leak a gallon a day as long as you keep it frequently topped off you will not have a problem (other than oil stained driveway and messy undercarraige), so I don't see how that problem would be oil leak related. How is your oil level?
 
Oil's fine.

Tranny fluid was changed when I bought it a few months ago. I'll recheck the level just in case.

Maybe it was not tranny related. some hesitation thingy. It just felt tranny related. I'll keep driving.
 
My 93 had similar transmission action occasionally, it would really hesitate and then kick hard into second on occassion, usually at parking lot speeds, wasn't really a problem I was concerned with. My 96 doesn't do it though, I assumed it was an idiosyncracy of the older tranny.
 
I would bet that the pan arch is the problem not the main. If the truck has been sunk in mud real bad, the I would say the rear main. It is not that hard to tell the difference if you use a mirror and a flash lite up through the hole in upper pan.
It has been my experence that most of the guys that have had their rear main replace soon need the oil pan sealant replaced as well. John you can buy a 4 dollar mirror and use a flash lite crawl under your truck. Pull the little black plastic plug out of the way. Use the mirror and look at the rear crank with it, if the seal is wet then it is the main, if the pan's grey goo is wet, the it is the arch. Another thing with the rear main, it will usually sling the oil around the inside of the bell housing.
It is real rare for a truck to need a rear main at the miles you have on this new crusier. Ask for help form some one that can turn a wrench on this. You may trust this mechanic, But we all make mistakes. Get a second look from some one.

Slick 621 you are talking about the lower pan, the black one. Yes it can be easyly removed and the sealant redone. But this is not where the pan arch resides. It is in the next big aluminum pan above the small one. It take about 6 hr in the shop to do both pans. If you look just in back of the small pan you will see a black plug in the alum pan. remove this and look with a mirror to see both the pan arch and the rear main and crank. later robbie
 
alia176 said:
After reading this, I checked out my slight oil leak and sure enough, it's the rear arch seal :frown: but not my main seal :D Someday when I'm snowed in the house and it's -20 deg outside, I'll fix it with some Right Stuff.
Ah, wouldn't that be now? Cold/snowy I mean?
 
Robbie mentioned the 6 hour time frame for doing the pans. That is how long it takes him to do it. This job requires lifting the engine up off the front mounts and would take a lot longer than 6 hours for someone who is not familiar with the job.
 

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