Delvac 1STOPPED my rear main leak..

[Greaser]

Have around 85,000 miles on my 99 Cherokee with the 4.0L straight six.Bought this vehicle new and it has always had 10W-30 Mobil in it.Started to get a little drip on the inspection cover about a year ago...the dreaded 100,000k rear main leak on the Jeep six.Put in the Delvac 1 5W-40 last oil change..about 2,000 miles on it thus far...the cover is DRY since I put in the Delvac 1...also my piston slap noise was cut in half..so far I love this oil...any ideas what might have cause my seal to close up?Is this a first...leak was STOPPED by synthetic

 

[TR3-2001SE]

My guess is its the viscosity of the oil being a 40 weight vs 30 weight. Being thicker has its advantages.

 

[Greaser]

quote:

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Originally posted by TR3-2001SE:
My guess is its the viscosity of the oil being a 40 weight vs 30 weight. Being thicker has its advantages.

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Well I used Mobil 15W-50 last summer and the drip was still there...my guess is the higher ester content in the Delvac swelled the bugger