A few thousand miles ago (she doesn't get driven much) my 01 4x4 5-speed w/ 103k miles crapped its second slave cylinder. I had it towed 30 mi. to a speed shop I had spent a lot of money with because I wanted a performance clutch and I thought that to drop the tranny, they would have to pull my longtubes. They did not! I got lucky.

While they were in there doing the Motorcraft slave cylinder and throwout bearing, I had them install a Spec Stage-1 clutch, replace the M5OD tranny rubber plugs, and replace the rear main seal with a Motorcraft for cheap insurance. Not only did they screw up the clutch install, but the new rear main was leaking like a sieve. (This is nothing new, they had the same trouble with 2 rear pinion seals.) He tried to tell me that you have to use a little RTV on the backside of the oil pan like you do on the front edge due to the timing cover sitting on top of it. I am not familiar with the back side, but I just knew it was the new seal. They mostly corrected the tranny issues and put a new Motorcraft rear main in and I watched it for several days after, then spot checked after a few hundred, maybe a thousand miles after.

Well, it appears as though I now have oil seeping from somewhere in the area again. The 2 bolts between the rear of the oil pan and the face of the tranny housing are wet with actual drops on the passenger side bolt and the one on the pass. side corner. The moisture from this oil doesn't even go 1/3 down the pan on the pass. side and just a little on the driver's side. The whole face and inner side of the steel plate at the front of the tranny is "wet", but no drips anywhere like on the oil pan bolts and not running onto anything else. I had sprayed all this down with brake cleaner and after about 50 mi. it was all back again. It's not bad, most would ignore it, but that's not how I work. The shaft area around the rear main appears "clean", but does not look oily. It also isn't anywhere else inside the tranny or flywheel.

It does not leak at all when parked. No drops in the driveway yet at all, or at work. I am now at 3,900 mi. and need an oil change, but it was 1 qt. low. I don't usually check it so I'm not sure if this is usual or not. Everytime I have checked it was around 2-3k and it was dead on, but this was years ago. Is there any truth to the RTV at the rear of the oil pan story? Any idea which this might be coming from?

BTW, avoid MC Racing in Shawnee, KS like the plague. They didn't just **** me off or do me wrong, but they are just flat out incompetent. What's really scary is their bread and butter is Z06's, Stangs, and all sorts of exotic muscle that they aren't qualified to work on.

 

Never mind didnt comprehend..

 

I have found that old seals down low (under the vehicle) get old/hard combined with road dirt usually end up cutting a groove where the seal makes contact. It can be difficult to see but just throwing in a new seal won't fix the leak. They make "speedy sleeves" that are metal rings that slide over and permantly cover the groove damage left by the old seal. They also make oversized seals for this issue as well. So, it really could be your rear main leaking again. In a 4x4 the pan is no easy job so either way you are in for some fun. I have an 03 with a 5.4 and my rear main is leaking a little but not enough for me to tear it apart yet.

 

You can also gouge the opening in the block with the seal puller if you're not careful.

We pulled my buddies trans out on his 01 V6 just to find out it was oil pan leaking. We put a fat bead of RTV across the back of the oil pan where it meets the block, and that bandaid fix was enough to keep it from leaking for 2 years.

Now my FIL's 01 4.6 4x4 is leaking....