Rear Main Seal question

ja1919 · May 4, 2005

I got a 1992 Mustang GT auto with a leaky rear main seal and leaky front trans seal...is it possible to fully blow out the rear main seal???..i wanna drag it at the local track soon..but will i do damage if i drive it like it is????...its got 98,000 miles

tunedin302 · May 4, 2005

It will get worse the more pressure you build in the crankcase (i.e. higher RPMS).

BaXTeR3221 · May 4, 2005

I wouldnt temp it, could be fine, could have problems. Its a crap shoot.

FastDriver · May 4, 2005

BS... Go run it. If your rear main seal was fully blown out, the engine oil would be pouring from your engine. Leady rear main seals are common and though you should keep and eye on the oil level, you won't hurt anything by running the car. To prove it, go put the car through it's paces a couple of times on a highway somewhere and nothing bad will happen.

Chris

HISSIN50 · May 4, 2005

and make sure the crankcase ventilation is up to par. otherwise, you will have the same issues after new parts.

i would add that a leaky RMS (if truley leaking) will get to your clutch at some point here. that is not exactly what you want for track runs.

good luck.

5spd GT · May 4, 2005

To counter FastDriver's (Chris) post... (you know I mean well)...my rear main seal leak got worse when I would take it to the track or go WOT on the streets...I HIGHLY doubt your going to actually blow it out...but my leak would get worse as the rpms climbed and for longer periods of time...it makes a nice smoke show when it gets on your clutch (slips/burns) and on the exhaust (burns off)...

FastDriver · May 4, 2005

Same thing in my case when I had a leaky rear main. Even if it's smoking that bad, though, he won't do any mechanical damage. I think that's his main concern.

5spd GT · May 4, 2005

FastDriver said:
Same thing in my case when I had a leaky rear main. Even if it's smoking that bad, though, he won't do any mechanical damage. I think that's his main concern.

I consider clutch/flywheel mating (drivetrain - aka. mechanical) a possibility for mechanical damage. It really would be smarter to stay out of hard throttle until it is fixed assuming the leak is significant enough. I wish I would have listened to my own advice

Many of "us" have small rear main seal leaks but you just have to determine how small is small...

tunedin302 · May 4, 2005

5spd GT said:
I consider clutch/flywheel mating (drivetrain - aka. mechanical) a possibility for mechanical damage. It really would be smarter to stay out of hard throttle until it is fixed assuming the leak is significant enough.

Agreed. Why go run a motor with a leaky RMS at full RPMs down a track only to glaze the clutch and return with a crappy time that doesn't reflect the cars real capability?

tunedin302 · May 4, 2005

FastDriver said:
Leaky rear main seals are common and though you should keep and eye on the oil level, you won't hurt anything by running the car.

.... except your clutch.

FastDriver · May 4, 2005

Alright, if his clutch was slipping I'm sure he would have mentioned it, but I'll cave - if your clutch is slipping and your RMS is so leaky that it is affecting your ability to launch the car, don't run it.

That said, a small leak is not a big deal and it will not cause your clutch to slip. At 98k miles, it is unlikely that your leak is even severe enough for you to see any smoke when you get on it. Like I said before, take it out on a highway, run it through the gears, and if you notice any problems, have it fixed before you embarrass yourself at a track. Otherwise, go have a blast.

5spd GT · May 4, 2005

Well the "deal" is that if you are putting out enough oil to get to the clutch components you can cause the slipping clutch which is what we are trying to get across to avoiding.

I did go to the track (stupid) with the seal leaking and just glazed the clutch bad...the timeslip givers thought I blew my engine...lol...and I could barely see the camaro in my rearview

Mileage isn't an indication of how bad a rear main seal leak is...but going WOT if it reaches a certain point will shorten the life of your "small leak" IMO.

FastDriver · May 4, 2005

And you didn't notice any clutch slipping problems before you went to the track?

5spd GT · May 4, 2005

FastDriver said:
And you didn't notice any clutch slipping problems before you went to the track?

Yes I did...but it sealed the deal with that trip to the track...but that doesn't exclude the "slipping problem"...what initially started it was the rear main seal leak which was stretched even more under street driving and WOT runs. It doesn't have to be at track or not...if you go WOT it is going to act the same. The engine doesn't know it is on the track compared to the street. Either way he needs to avoid WOT runs "in a perfect world"...if his leak is to a certain extent.

Mustang5L5 · May 4, 2005

You can't really blow it out. The back of the flywheel almost buts right against it and the rear main is a pretty thick seal. It's in there tight.

With that said, every 5.0 engine i have ever removed has had a leaky rear main to some degree. Some dribble down never hit the ground, others make a few drops every time the car gets parked.

FastDriver · May 4, 2005

Mustang5L5 said:
You can't really blow it out. The back of the flywheel almost buts right against it and the rear main is a pretty thick seal. It's in there tight.

With that said, every 5.0 engine i have ever removed has had a leaky rear main to some degree. Some dribble down never hit the ground, others make a few drops every time the car gets parked.

I've been into about 10 5.0s and always see at least a slight leak.

bobbys9350 · May 4, 2005

FastDriver said:
BS... Go run it. If your rear main seal was fully blown out, the engine oil would be pouring from your engine. Leady rear main seals are common and though you should keep and eye on the oil level, you won't hurt anything by running the car. To prove it, go put the car through it's paces a couple of times on a highway somewhere and nothing bad will happen.

Chris

BaXTeR3221 · May 4, 2005

Anyone notice that he doesn't have a clutch ....but both my stangs had leaking rear main seals that were dripping oil all over the clutch.

5spd GT · May 4, 2005

Baxter - Good point...lol. But the "clutch disclaimer" can be used for someone that just read FastDriver's post at face value and think they will be fine...but the clutch issue needs/needed to be addressed as JT said for a potential reader thinking it would be just okay to go WOT anytime he wants with a leak...

FastDriver · May 4, 2005

LOL...he doesn't have a clutch.

Rear Main Seal question

Member

I AM the law!!!

Member

I was uncomfortably high & wearing a helmet

"How long does it take to get help in here?

"the 5.0 owns all"

I was uncomfortably high & wearing a helmet

"the 5.0 owns all"

I AM the law!!!

I AM the law!!!

I was uncomfortably high & wearing a helmet

"the 5.0 owns all"

I was uncomfortably high & wearing a helmet

"the 5.0 owns all"

That is…until I whipped out my Bissell

I was uncomfortably high & wearing a helmet

New Member

Member

"the 5.0 owns all"

I was uncomfortably high & wearing a helmet

Similar threads

Privacy & Transparency

Privacy & Transparency