How Common is a Rear Main Seal Leak on 11-14 S197 GT?

[Massimo]

Hey folks,

I'll be going in to the trans area to replace my clutch and flywheel this weekend. Replacing the OEM clutch with a McLeod RXT and McLeod billet steel flywheel, as well as replacing trans slave cylinder, pilot bearing, and installing a McLeod stainless clutch line. Since I'll already be behind the flywheel, I am considering also replacing my rear main seal. How common is it to see a rear main seal leak on the 11-14 GT Mustangs at higher mileages?

I don't have a ton of time this weekend, and the rear main seal replacement will take an extra 1-2 hours with removal, resealing the rear main seal retainer, and re-installation. Also, I'm thinking about the added risk of scoring the crankshaft or rear main seal retainer as opposed to just leaving the current one in there that does not leak. If these cars never leak from the RMS even when they're at higher miles, I think it'd be best not to bother. But if y'all have heard of rear main seals on these cars leaking before, I'll likely opt for replacing it.

For reference, my car is a full bolt on 2013 Mustang GT with 5.0 engine and MT-82 trans at 128,000 miles, and I don't plan to stop driving it or driving it hard anytime soon.

Any other tips and tricks on clutch and flywheel installations are welcome too. Thanks in advance!

 

[stevbd]

I have an '11 GT and the RMS started leaking at about 140K miles. Daily driver with lots of track days.

I'm a little embarrassed to admit I used Lucas stop leak which has done the trick and now I'm at 160K. Mine is all original engine/clutch/tranny and has never been opened so I didn't feel like opening it up unless I had to. But it's a band-aid for sure and when I do the clutch, which I figure has to be pretty soon, I will definitely do the RMS.

 

[2012-Boss]

Unless you have the Ford specialty tools called out in the service manual for RMS removal and installation, leave the seal alone. The tools cost about $600.

 

[blacksheep-1]

I always run Lucas in all my cars, in every application they make a product for. I started doing that in order to get my 1970 MG Midget to live on the banks at Daytona with a wet sump. A trucker friend of mine gave me the tip. Like the commercial says " I put that ++++ on everything".
I suggest you do the same.

 

[Massimo]

Unless you have the Ford specialty tools called out in the service manual for RMS removal and installation, leave the seal alone. The tools cost about $600.

This is good to know. I had no idea special tools were required. I watched a YouTube video on an 05-09 RMS replacement, and I knew the 11-14 would be a little different obviously, but didn’t realize it was different to the length of special tools.