Give me your opinions
 

Pulling my nv4500 to have it rebuilt.. having the flywheel resurfaced at the same time(and pilot bearing replaced), what do ya'll think about doing preventive maintenance on the engine by replacing the rear main seal while I have the flywheel off? No, it's not currently leaking, but the motor has 200k on it.. rest of the motor is strong, just thinking about replacing an aged seal before it has a chance to go bad..

Re: Give me your opinions
 

If it is leaking, any yeah, now would be a good time. If there is no leaks, don't worry about it. Is this a V6?

Re: Give me your opinions
 

Yes yes yes. It'll be your luck it will start leaking 3 months after you put it back together if you leave the old one in there.

20+ year old oil seals don't last forever.

Re: Give me your opinions
 

I had two trucks with NV4500s. Anytime the engine and transmission got separated I replaced the rear main seal and transmission input seal AND bearing. That stuff will be new on your trans. But I kept a spare bearing and seal.

Re: Give me your opinions
 

Of course replace it. You already did all the labor getting to it.

Re: Give me your opinions
 

Thanks guys.. getting the last of the needed parts today, and then the fun begins..

Re: Give me your opinions
 

I am with the others, it's apart so replacing is easy enough, I would get quality seals though and Lisle makes a cool blind seal puller.

https://www.youtube.com/watch?v=YrVwf6BHLTw