Second Front Main Seal in 65k miles

[Kong76]

Evening fellas and ladies, i have a 16 Gt with 65k miles. I had the front main seal replaced around 19k due to an oil leak around harmonic balancer.

Well last week i went and got an oil change and noticed after several days the oil smell with the heater on wouldn't dissapate. Found the harmonic balancer with the identical wet look to it.

Cleaned it off with simple green to see if it would come back and tonight i got my answer. Im now kind of worried about crankshaft issues. Seems odd to eat up 2 so soon unless they misaligned the timing cover when replacing tensioners at 7k. What do you all think?

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[Cobra Jet]

It could be a timing cover issue, but in my experience that’s a rare instance.

Aside from a bad install of a seal (which wouild be known in the first few miles of being replaced,) the most common issues would be:

- No sealant or degradation of existing sealant on crankshaft key way.

- No sealant or degradation of sealant on the crankshaft snout bolt.

- The harmonic balancer shaft is grooved by the seal and oil is seeping past that groove.

The same type of grooving happens with the rear main seal oil leak issues on Mustangs. Many think it’s the seal, but 99% of the time on a vehicle with accrued miles (50k+) the reason the leak exists in the first place is eventually the harmonic balancer shaft or rear of crank gets a groove worn into it from riding between the seal. This groove in many instances is not huge, it’s like fingernail deep and is visible when removing the harmonic balancer OR if able to see the rear of the crank in engine with a bright light and mirror.

That is all it takes to allow oil past those (2) seals, whether a brand new seal or an aged seal. Over time, the leak just gets worse because the seal can no longer seal where that groove is located and the groove does continue to deepen. Also if there was any small debris in the oil as the rotating assembly is at RPM, that small debris can get wedged between the front or rear seals causing a scrape to the harmonic balancer shaft or rear crank surface, again causing a front timing cover leak or rear main seal leak.

However there are front and rear seal repair sleeves. IF the front (harmonic balancer shaft) or rear main (crank) has a groove, the specific repair sleeve slides over the harmonic balancer shaft or over the rear of the crank and creates a new smooth surface between the seal and the harmonic balancer or crank. It should last for 50k-100k or better depending on how the vehicle is maintained and its use. If those repair sleeves ever get a groove or is worn out at that later interval, then all that needs to be done is removal of the initial repair sleeve and pop on a new repair sleeve.

The sleeve requires special install tools that can be found anywhere online or at parts stores. There are plants of YT vids too showing how to do a repair sleeve instal. You need the correct repair sleeve for the engine application and it must be specified whether front or rear. Some have installed the sleeves without the tool by using PVC pipe cut to size, but it’s all personal preference and how experienced one is with engine repair.

Now I do not know if these repair sleeves are available for the Coyote 5:0 variations, but I would suspect they are since many Coyotes have high miles now. Check around. FelPro is usually the main distributor of the repair sleeves (and tool), but these are also manufactured by Victor Reinz and a few other well known engine parts suppliers.

Hope the above is helpful.

 

[Kong76]

Thank you very much for that detailed response. Thats a tremendous amount of knowledge. I will mention this if and when this one gets repaired. So far they said its a seep and added dye to the oil to determine where exactly.

Again thank you

 

[shogun32]

have the shop mic the rubbing face(s). and consider getting it polished

 

[Kong76]

Popped the hood to check and its starting to weep again from the inside of the harmonic balancer by the bolt out. Slow weep.

Wondering if I should use this as an excuse to get away from the mt82 and buy the 24' 10spd. They are offering 1.9% for 36 months. Like having no car payment though.

 

[Cobra Jet]

Popped the hood to check and its starting to weep again from the inside of the harmonic balancer by the bolt out. Slow weep.

Wondering if I should use this as an excuse to get away from the mt82 and buy the 24' 10spd. They are offering 1.9% for 36 months. Like having no car payment though.

If the oil is coming out the center of the harmonic balancer past the bolt, then:
- The bolt needs to be removed and sealant reapplied to the bolt (and same should be done with keyway if possible).

If the center was dry and the oil is around the inner perimeter of the seal between the harmonic balancer shaft, then it probably needs a repair sleeve and new seal.

 

[Kong76]

Im going to show the tech this.

 

[Cobra Jet]

Im going to show the tech this.

Is this a Ford Dealer? They should certainly know how to diagnose/fix that, it’s like Changing Oil 101…. LOL…. If they can’t get that right, sorry to say but maybe find another Ford Dealer (if possible).

 

[Kong76]

Yea its the dealer. I would hope so but with todays world who knows. They replaced the seal at 17k and i might be in the same boat again.

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