Good morning and other times,

I am posting here to hopefully get a little guidance on an ongoing oil leak that I am dealing with. I will start by saying, it is not a major oil leak but it is enough to irritate me. I simply do not like finding oil spots on the ground beneath my truck because I figure that if oil drip spots were supposed to be there then the truck would drip as soon as it is filled with oil at the factory.

Allow me to set the scene: the oil collects and drips from the inspection plate that is at the front of the tranny bell housing (I initially suspected rear main, as did all of my uncles, friends, and father; more in a moment). It appears to run backwards (as the truck is in motion) to get there but I have not fully determined where from. I can tell it runs more whenever the truck is moving because it gets on to my exhaust and I can see some streaks along the driver side of the oil pan. If the truck sits for a couple days, oil will only drip for the first 12-24 hours and then it will no longer drip until after the next time I drive it. Over time, it got worse and as a result I diagnosed some possible locations but have not resolved the entire issue. At this point it has to be coming from somewhere above this location and here is why.

A month ago, my uncle and I went to work. We pulled the tranny to change the leaky oil pan gasket and probable rear main and found that the rear main seal was F***ING spotless. We changed it anyway because I bought one and we were staring it right in the a**hole. I was confident my problem was solved. WRONG. My situation improved but is not completely fixed. We then changed the front crank seal because oil appeared to be running backward from the lower front of the engine also. That thing looked like blown out cow p***y. It needed to go. Sure enough, there is no evidence of an oil leak from there anymore but there is still a leak that collects and drips from the inspection plate. I have a valve cover gasket seal kit that I intend to use for s***s and gigs but I do not think that is the cause of my leak.

My next guess is that it could be the O-rings/seals on the oil filter adapter. I have read that this one requires the exhaust manifold to come out also. My question is, am I missing any other culprits here? What other seals might it be?

I know it is motor oil, not tranny fluid.
I also know that my oil filter nipple is clean and I always ensure that the old oil filter gasket comes off before the new filter goes on.
Through the process of elimination, I am narrowing down my field of suspects.
My uncle says I care too much, please do not think like him. I just like leak free s***.
If you can help a desperate fella out I would be much obliged.

 

Welcome to the forum

What YEAR Ranger and what engine is it?

Put some UV Dye in the oil and see where the trail leads you

If its a V6 engine could be rear cam seal but would have expected you to see that when doing the rear main

Was oil on the INSIDE of bellhousing or the OUTSIDE, as seen when trans was pulled back?

3.0l has oil pressure switch behind passenger side head, if its leaking it would run down outside of bell housing and drip

 

RonD,

It is a 2004 Ranger with the 3.0L V6.

UV dye will be my next step in the process to see where it can lead me. I will give updates on what I find.

"Rear cam seal" - Are you referring to that plug that is directly north of the rear main seal? Definitely possible from what I have found online which indicates this could be the issue. However, as best as I can remember when we did the rear main it was clean up there (it has been almost two months ago now).

When we had the transmission off I was focused on the oil pan gasket leak which had created a wonderful mess outside the bell housing and on everything else down there. I think there were several leaks in different areas that all sprung close together because the mess has gotten better after each seal replacement. So, when the transmission was off, the mess I was focused on was outside the bellhousing.

When we changed all the seals previously, we cleaned everything up really nicely which has helped show trace marks of this continuing oil leak. Now, it appears that the oil that drips off of the inspection plate is passing between the bell housing and inspection plate.

Thank you for your input!

 

Yes, that's the rear cam passage seal, very rare to have a leak there but rare is not never

Picture here: https://www.motor.com/wp-content/upl...28.59-AM-2.png

 

RonD,

Updates a comin' at you. So, I bought some UV dye two days ago after work and drove her home (about twenty minutes ride). I was not able to get any great visual of the dye on any exterior part of the motor or frame. I DID however see some of the dye up between the inspection plate and oil pan. I thought "well it is either that cam plug he mentioned or it is in fact the rear main" because the leak is contained somewhere inside the bell housing. I was hesitant to think it could be the rear main that I had previously changed but a little reason and humility told me it might be that seal. I thought on it and researched some more because I do not remember seeing any mess on the back of the block months ago. I mean it was clean.

After a little digging through a similar Ranger Forum I stumbled on a thread from a guy who was in a very similar situation. The difference is that he has changed many a rear main in his life to my only one (this one). Turns out that I made a rookie mistake (so did this other guy) and did not read the paperwork in my Fel-Pro seal kit which says "IMPORTANT: This seal should be installed dry." I had no idea and did not think about it because I have lubed every other circular seal that I have ever done. Turns out that in the Fel-Pro seal kit BS40646, there is a PTFE rear main seal. These are specifically designed to go in dry and create an excellent seal after receiving an increase in temperature. If they go in greased or oiled they just will not seal properly.

I am almost certain this is the issue. The transmission is coming back out this weekend and a new PTFE seal is going in DRY. Alternatively, an OEM rubber seal could be used and installed conventionally (lubed) with no issue but I want to give this Fel-Pro PTFE seal another go. Reviews and opinions say it is a great seal if done correctly.

Thank you RonD for getting the ball rolling. Without your encouragement it would have taken me longer to determine that I SNAFUed the first seal. Ya live and learn I reckon. I will put another post on here to confirm or deny if that was the issue once I get the job done.

 

Good research

But look for the dye when transmission is off just to BE SURE
You would only see it below the main seal

 

RonD,

So, this past weekend I dropped the transmission back out of the truck. Sure enough, the bell housing had some motor oil in it that contained UV dye. The rear main seal also had clear evidence of a leak that contained UV dye. The rear cam passage seal that we discussed previously was clean as a whistle. I figure that the leak must have been from me not following Fel-Pro's instructions when installing the PTFE seal. I replaced the seal Saturday March 6th, making sure to follow Fel-Pro's instructions and buttoned everything back up. The instructions say to not add fluids or crank the engine for at least four hours. I let the truck sit overnight before doing so (about 16 hours).

I have been driving the truck yesterday and today and there is still oil that collects in the same spot as before. It is a far smaller amount now but it gathers just the same. It is not enough to drip off either, it just gets to the lowest point of the bell housing and hangs out there. I cannot imagine that the rear main is continuing to leak. I did everything that I knew to do. I read (after the fact) that sometimes the "sealing journal" is compromised and may cause issues, even when the seal install was flawless. I recall that my crank is clean and free from scratches or dings. I read further that the seal should ride in the exact same spot as before while others say that it should be in a different spot. Any ideas here?

The side of the block where the oil filter attaches is visibly wet though, right beneath the oil filter/nipple where the filter threads on. I disregarded this before but I noticed while I had the transmission off (as I was cleaning up down there) that some of my parts cleaner/degreaser spray ran from that point, along the bottom of the engine, and dripped right into my lap from just below the rear main seal. I watched it. I suppose that the oil filter seal may be compromised. As I said previously, I always ensure that the oil filter gasket comes off with the old oil filter during an oil change. I also lube the new oil filter gasket surface and do not crank the filter down, hand tightened only followed by a miniscule "snugging" with the band wrench. Maybe the oil filter gasket of this particular STP S3600 oil filter is also supposed to be installed "dry" ha. ha. I am only brainstorming here. I read some opinions that FRAM, STP, Mobil1, etc. filters are all junk and you should only use Motorcraft filters. The guy who bolsters that opinion must be a real purist. Any thoughts?

I am unsure if I should just accept that my truck is a leaker now or to be persistent and continue to try to fix it. Really dreading the idea of pulling the transmission again but if it is necessary then I reckon I will do it.

 

Its possible the original seal left residue that's allowing oil to pass, does read like its not too bad now but if you go back in you might want to use Crocus cloth on the crank journal to polish it and remove any residue, just to take that off the table

Because of the rotational speed of the crank any slight residue will cause seal to deform momentarily and there is ALOT of oil at that rear main bearing location trying to get out

 

I failed to mention that I did use emery cloth on the crank the first time I changed the seal. I did not use emery cloth the second time I changed the seal. It is entirely possible that I missed something but that thing felt and looked clean last Saturday. I should have taken a photo.

I have some pictures here of the area beneath/around the oil filter nipple. You can see that it is visibly wet and it feels wet too. Images 1 and 2 are from my point of view while lying beneath the truck. Image 3 is also from beneath the truck though I was curious about that tiny plug that I have circled there. Do you have any thoughts? Image 4 is viewing the area through the driver side wheel well.

I changed the oil filter last night from an STP S3600 to a Motorcraft FL-400S (what the owner's and Hayne's manuals call for on this engine). I cleaned that gasket seating surface in the picture well and wiped up around it as best as iI could also. Here is to hoping.

I greatly appreciate you help in troubleshooting thus far, RonD. Cheers!


Image 1.

Image 2.

Image 3.

Image 4.

 

I am just going to leave this here for closure on the issue. I have a buddy who was recently telling me that nothing chaps his *** more than forum posts who never have any closure explaining what the solution was. RonD, I appreciate all of your input and advice. You are both a gentleman and a scholar. Keep up the good work, sir.

It turned out that in the process of changing all of the seals that I changed in the area (rear main, front crank seal, and oil pan gasket) when I first began trying to resolve my oil leak issue I created this leak. The good news is that the leak is gone because I changed the oil pan gasket again. It turned out the the oil pan bolts had not quite been fully torqued and the gasket had become oil soaked and therefore did not create a good seal. It was one of the Fel-Pro ones that has the blue silicone on either side. I replaced the guy with a new one and was sure to properly torque it and it has created a nice seal. I am leak free yet again.

This one is for you bud. If anyone is running into oil leak issues be sure to listen to RonD. The man certainly knows how to be helpful.

Thanks again and good luck Ranger nation.

 

I am blushing

Thanks for the follow up and fix

 

This thread deserves some kind of award.