Oil has been leaking from my engine rear main seal and have changed the seal three times already. Believe there might be a groove on the crankshaft.

Wondering if I applied silicone lubricant or high temp urea grease on the crankshaft would stop the oil leak.

 

anyone know if the grease/silicon would melt or get mixed with the engine oil if applied?

 

If the crank is grooved you need a new crankshaft to fix the leak.

 

new crankshaft? it's almost 1g new from the dealership

 

Thats nothing compared to the labor to change it

 

Some people in the Miata forums have been able to smooth ridges on worn cranks and then get a decent seal.

You really need to pull the tranny again, confirm that the rear seal is leaking, then pull the seal and carefully inspect the crank for wear, ridges or grooves. If you can't fix the wear with emory cloth, then you'll need to replace the crank. Silicon seal will not work in the long-term and you can't effectively add metal to the crank to smooth it out when it's installed. If there is no wear, perhaps it's your installation method that's the problem. Make sure that you have the correct part and that you're installing the seal in the correct direction .