Leaking rear main seal

[HemiHawk]

Hey all,
So my recently acquired 1995 Mustang has a leaking rear main seal. Not sure if the oil I started running in it (Pennzoil Plat 10w30 HM) cleaned anything and caused the leak, or if it was just its time.

Is there any trick to lessen or slow the leak? I know the seals are about $30, but I don't know if I'm up for pulling the trans and clutch to get at it. Maybe when the car needs a new clutch, but at 85k miles the clutch feels OK.

 

[buster]

Some HM oils can slow/stop a RMS leak. My brother's 2001 Solara had a rear main leak and Mobil 1 HM stopped it.

 

[JustN89]

Considering you're already running a HM oil, the first thing I'd try is switching brands. It's the easiest and cheapest thing to do, so why not start there. Maxlife has been my go-to high mileage oil, but that shouldn't stop you from trying M1 HM or Castrol HM.

 

[HemiHawk]

I should add that I picked up the car at 84,000 miles, and swapped out the oil when I got it for the high mileage oil. I'm thinking if the high mileage oil does help, maybe it needs more time? The problem is, it seems to be a decent drip. When inspected the mech said it wasn't bad enough to worry about, but seeing clean oil hit the driveway is kinda rough.

Anyone have experience with this stuff? https://store.gobdp.com/rear-main-sealer-00234/ . I've hear bad things about "stop leak" type products in the past but maybe worth a try?

 

[Trav]

Check this thread out. I wouldn't mess with Blue Devil stuff.

 

[fcjeep]

A few years back, on my Jeep GC, I had a small front seal leak. I added a bottle of ATP 205 and it stopped the leak within approx. 2,000 miles. It was still holding after about 15,000 miles before the engine died of a dropped valve seat.

There's a thread or 2 on BITOG about that stuff.

 

[AZjeff]

Interesting that some RMS leaks are slowed or fixed by HM oil or additives and some aren't helped at all. And one brand of HM oil doesn't work but another one does. I tried ATP-205 in the Xterra and it didn't help a bit. Maxlife HM might have slowed it a bit.

Pics of the Mustang or it doesn't leak! Car porn always welcome.

 

[citationxeleven]

I tried the ATP in my Camry, it did not help at all. I ended up having the seal replaced, expensive but no more leaks.

 

[JamesBond]

I would leave the oil in there, it will take a couple thousand miles to work, if it works at all.

At 85k miles you might need a clutch soon anyway or maybe the oil leak will contaminate the clutch and you'll have to replace it. Either way, the solution is the same.

I guess my point is, put some cardboard under the car and keep on driving it. Let the car tell you when it's time to change it.

 

[HemiHawk]

Originally Posted by AZjeff


Pics of the Mustang or it doesn't leak! Car porn always welcome.


I don't have any really great pics of it, but here are a couple - The stuff on the tires is grease from when they installed them, hadn't washed it at that point haha.

That one it replaced was prettier, but this one has some charm.

 

[bullwinkle]

I would try MaxLife red bottle synblend in it, it has worked wonders for me in the past. Plus it's a pretty good oil too!

 

[SatinSilver]

Originally Posted by bullwinkle
I would try MaxLife red bottle synblend in it, it has worked wonders for me in the past. Plus it's a pretty good oil too!


Same here and prob in the Xw30 flavor or thicker for the application mentioned.

 

[spk2000]

I tried maxlife in mine and nothing, ATP-205 again nothing. Mobil1 HM 10w30 so far so good in stopping it. Might get around to fixing it right but for now no more leaks.

 

[ofelas]

Oh yes. Try different types of oils. Because actually changing the rear main seal out is so yesterday.

 

[SatinSilver]

Oh yes. Because it's real easy suggesting spending an extra $750 when you're not paying the bill.

 

[ofelas]

Ah, you take it to a shop for mechanical repairs. My bad, I do all my own work.

 

[SatinSilver]

Pretty impressive with the old heaps you own.

 

[StevieC]

RCY on here had a RMS leak in his Acura MDX shortly after he got it (used). He has been running thicker weight oil to keep the leak to a minimum (seepage instead of drip). Has driven it like that to 400K KM's (240K miles) and it's still going.

 

[sloinker]

Originally Posted by ofelas
Ah, you take it to a shop for mechanical repairs. My bad, I do all my own work.


I just replaced a sensor on my '14 Dodge. Dealer wanted $700. Sensor cost $25, special socket cost $10. $35 and 30 minutes is what it cost to repair. I always do my own work.
As far as the OP's Muffstain, RMS is gonna run $10-$35. May as well throw a clutch kit at it when you pull the tranny, another $150-$300 for OE equivalent. 4-6 hours to R/R at my house which has a lift and tall tranny jack. Double those hours for someone with jackstands and a floor jack. I would still wait until the clutch starts to slip and repair myself. Nothing easier than a RWD vehicle for tranny work.

 

[AZjeff]

And it's just really hard spending $750 to replace a $20 seal. Not saying it's a quick easy job but still.