Any Rear main seal leak repair additive actually work?

[REBrueckner]

Anyone have any experience with using an oil additive to stop a rear main engine seal leak?

If the crankshaft has some corrosion contributing to the problem, chances are dim that any additive can help. Engine is a 1970's Cummins VTA903.....Engine was unused for about four years. Runs well otherwise. Big job to disconnect shaft, disconnect and remove tranny to make the repair,and reconnect all. Any other alternative?? steady drip observed below back of engine, cannot see the actual location, but other sources have been visually eliminated..

One online source 'expert' says: Will an additive work?

"Unfortunately not. Seals usually leak because of excess pressure, the shaft they are sealing starts to move or more likely in this case, because they have gotten hard. The most common cause of seals getting hard is not frequent enough oil change intervals. Additives claim to work by swelling seals. This normally has the effect of breaking down the rubber and making not only this, but all seals in the engine far worse. A proper repair will not only be effective, it will be far less expensive in the long run.

 

[Boatsb]

You asked and answered it.

 

[Summerfun]

I have hear that putting a quart of Automatic Transmission fluid in the oil will work to Swell the seals but not break them down.

 

[JLR]

Careful with ATF. I know someone who burned up a clutch by using ATF in the tranny. If the rear main seal is shot, there is likely a transfer of fluids between the tranny and the engine.

 

[luckydave215]

Careful with ATF. I know someone who burned up a clutch by using ATF in the tranny. If the rear main seal is shot, there is likely a transfer of fluids between the tranny and the engine.

What do you have to lose? If it doesn't work and burns a clutch plate, well you had to R+R the tranny to fix the seal anyway.

 

[yachtsmanbill]

Doubtful that the 903s used Allison gears... ws