Rotella Synth.. rear main seal worse

[OiledMustangGT]

I had previously been using Mobil 1 10w30 then I took a try of Supertech "full synthetic" one time... during this time the rear main leak was confined to a light coating of oil below it. I recently just tried Rotella 5W-40 synth. it has been in for about 2k... the rear main seal is now dripping.. no real oil loss can be seen on the dipstick though. Should I try some High Mileage oil like castrol 10W-40 next time?


4.0L jeep

 

[uconn1150]

Better to fix the problem now, than let it get worse. How many miles are on the seal? I would do an auto-rx treatment ASAP and possibly save the seal. What car is it?

 

[MariusVT]

maybe give it a try with some High Mileage oil or some castrol gtx and some autorx... Im 700 miles into autorx and I had a small seepage at my rear main when I started and it has all but stopped now... no oil loss that was noticeable when it was leaking though so it wasnt bad at all.

 

[OiledMustangGT]

jeep 4.0L with 80k and 8yrs... a very common seal problem, just about every jeep 4.0L with over 40k has some rear main seal leakage to some extent.

I can replace the seal myself for like $30 when that time comes, I just did not feel like doing it till absolutely necessary cause it is a semi- PITA/messy job.

 

[unDummy]

With the leaky oil now, try one of the over the counter motor honeys(VI in a bottle). Valvoline/STP/......might help now.

At the next oil change, use a High Mileage oil.
I have successfully used High Mileage oils to stop leakage in several cars. Its cheap. Give the high mileage oils a try.

Pricewise, I bet a gamble with Autorx should be next. Lastly, just have the seal replaced.

 

[Gary Allan]

Stick or auto? The only problems that I've seen with a leaking rear main (other than a "null and void" engine) are oil soaked clutches ..which takes a while for enough oil to get whipped around off the flywheel to do anything. My rear main is "seeping".

I'd go through my regular OCI with the Rotella ..perhaps do a AutoRx treatment using recommended conventional oils ...see what happens. I haven't seen too many bone dry two piece rear main seals ...especially on manual transmissions.

The top seal is a PITA to get. It's one of those "acquired skills" ..but at least you don't have to pull the trans like on a one piece.

 

[dickwells]

My experience has been that a leaky rear seal is made worse by going with a heavier viscosity oil (raises the oil pressure). If you want to minimize leakage stick with the Mobil 1 or a high mileage 5W30.

 

[OiledMustangGT]

auto

 

[Gary Allan]

Auto? Then why sweat it unless you're getting a puddle ..or it's making a mess of your driveway or garage floor? Every two piece I've ever had typically leaked to some degree.

AutoRX may be worth a try. It stopped my 92 Caravan and my daughter's 91 Taurus from the "drips" due to leaking gaskets. I never did find where they were leaking from.

I still wouldn't waste perfectly good Rotella.

 

[OiledMustangGT]

i stayed it out till 3,500 miles were on the oil and the oil leak started dripping a little more than i was comfortable with after a 6hr x2 trip @ 70+mph

( hurricane evacuation ) . the oil had turned very dark too (guess rotella did have some strong detergents as posted before). I put in some castrol GTX HM 10w-40 today