View Full Version : Rear Main Seal Leak (?)
jwebb
05-21-2018, 12:29 PM
Pretty sure I've got a rear main seal leak based on spots on garage floor, debating using some sort of sealer and wait until clutch, TOB replacement, etc. or bite the bullet now,pull the tranny and replace. Not having a lift available, can the tranny be pulled using only jack stands?
CDXXVII
05-21-2018, 12:37 PM
If your transmission tunnel cover is removable it makes for a much simpler task. We used the engine hoist and some straps on the transmission to take it out. Secure the engine first. Remove the drive shaft first.
Only sure way to fix a rear main seal is to replace it. The mechanic in a bottle fix is like buying lotto tickets to finance your retirement -- neither is likely to be successful.
DadofThree
05-21-2018, 12:50 PM
I could only move my transmission back, but unable to remove with the motor still in place. Coming from the top and holding the transmission in place was the easiest for me. Since you have the aluminum in place, you may have some trouble getting to the bell housing bolts. Make sure you can reach each one of those bell housing bolts before starting any disassembly. that will give you a good idea whether to tackle the project or not.
Album of Pics (https://www.flickr.com/photos/annabellerose/albums/72157689192995640/with/41019798641/) showing my flywheel and rear main seal change I did a month ago Good Luck.
https://farm1.staticflickr.com/811/41019798641_040aff9764_z.jpg (https://flic.kr/p/25uMc2B)20180324_162853 (https://flic.kr/p/25uMc2B) by D. R. (https://www.flickr.com/photos/annabellerose/), on Flickr
rich grsc
05-21-2018, 03:53 PM
If I had a dime for every time someone thought they had a rear main seal leak, and paid a dollar for every time it was true, I'd still be rich. Rear main seal leaks on Fords are just very uncommon. Check the intake manifold and valve covers closely, also the pan corners which is usually the most like place to leak. Any oil leak is going to migrate to the rear.
boat737
05-21-2018, 03:56 PM
Make sure it is indeed a rear main seal leak. A couple of us have had leaks that look just like that, but after chasing the oil trail, discovered it was valve cover leak.
BB767
05-21-2018, 06:52 PM
Ditto;
I have had two leaks now that I could have sworn were main seal and head gasket leaks. One was the pan, one was the valve cover. Amazing how that oil can "snake" it's way around and convince you it is coming from somewhere else.
TexasAviator
05-21-2018, 11:42 PM
oil is a very tricky fluid, it will make you think its coming from one place but attach itself in a tight area and run to the rear of the engine. Do you have an oil catch for your pcv setup? Does your pcv come off the back of the motor? Is it allowing oil to leak behind the bell housing. The other culprit can be bad venting of your valve covers or crank case. I have had all these leak on several cars before a rear main seal ever leaked. Now old jeeps? They leak at the rear main, but I bet a ford as new as yours has a leak from some issue with pcv setup. I use a steeda oil air separator and it catches a few drips on just short runs in the car
RickP
05-22-2018, 06:57 AM
I will second/third the notion that it’s probably not your rear main seal. Fords are notorious for dripping oil at the bellhousing. Most always caused by one or more of the aforementioned sources. Start tracing high on the engine with your finger and work your way low. Valve covers are the usual culprit.
broku518
05-22-2018, 01:26 PM
Pretty sure I've got a rear main seal leak based on spots on garage floor, debating using some sort of sealer and wait until clutch, TOB replacement, etc. or bite the bullet now,pull the tranny and replace. Not having a lift available, can the tranny be pulled using only jack stands?
You can see spots on the floor, but what is the pattern on the engine/bell housing/tranny? Can you trace it upwards?
I had a similar scare the other day, freaked the s*** out. Then traced it to valve covers.
Engine Factory
05-22-2018, 03:59 PM
If you do have a rear main leak, putting a new seal on it may not fix the issue. We like to put a replacement sleeve on the back of new cranks to give it a new surface and slightly more interference fit for the seal to ride on.
Here is a kit we have in stock - https://tdmotion.com/product/351w-rear-main-seal-repair-kit/
or available for a 302 - https://tdmotion.com/product/302-rear-main-seal-repair-kit/