Replace Rear Main Seal? Leaking?

[genhawk21]

1997 2.3 @ 357,000 miles. Doing my first-ever clutch (because of a leaking slave cylinder) although it is certainly not the first clutch for this truck. Finally peeled it all back to the rear main seal. I have one on hand but I'm hesitant to replace it, because I have a bit of a history with "if it ain't broke I'll fix it until it is" and I've been trying to learn to not molest things that are fine. Pic is exactly how it looks, I haven't touched or cleaned anything. What do you smart people say? Is it leaking? Should I replace it? Or leave it alone? I'm not experienced enough to tell if the RMS is leaking or the gunk is all from up above.

On that note as far as I can tell the replacement protocol is to put a few screws gently in to pry out the old, then carefully press in the new with whatever works. Does that sound right?

 

[Sloryd66]

Looks like gunk and not leaking. It’s a tough call but I’m kinda like you…an if it ain’t broken person. It’d suck if you went through the trouble to change it and the new one didn’t seat right and developed a leak you didn’t have. That’d be my luck. The crankcase is under pressure and if that was leaking, it would present more than what your pictures show. Just my .02, but if it were me, I’d leave it alone for now. You know best the time it took to yank the tranny and clutch assembly…would you be willing to do it again down the road if/when it did leak? That’s what you should base your decision on if you’re still on the fence.

 

[RonD]

The "if it ain't broke don't fix it" is a good rule

But you have to adjust it for "how hard will it be to fix if it broke", lol

Yours is not leaking and may never leak
If pulling the transmission is NOT on your "I never want to do that again!" list, then I would leave it as is

If this transmission removal has been a big PITA then replace it

Yes, common method is to drill 2 pilot holes in the seal and put in screws, when screws are tightened their tips will push against the block and seal will start to come out
Check the crank race(where seal rides) using fingernail to feel for any ridge(s), if its smooth then install the new seal
Oil/lube the new seal
Put it in place, a use a piece of wood or non-metal part, to tap around the edges until its in place all the way

 

[genhawk21]

Thanks folks, I appreciate the advice! I'll leave it for now. I forgot to add that although it's a new truck to me, in the first 1.5k miles I didn't see any sign of serious oil leaks. There was a little oil leaking from the valve cover gasket which I've already replaced, but overall it's not a dripper.

This is only the second transmission I've ever pulled but I didn't find it that horrible. I'm sure I can do it again in half the time next time if need be. The only part that flummoxed me was the top two bolts (easy enough when you know to let it down a ways) and one of the side bolts I couldn't get a good angle on and had to go find a curvy 13mm for. We'll see how I do putting it back in lol. I didn't do a good job of keeping track of which bolts went where and it looks like they come in four lengths. If anyone has notes on that I'd appreciate it. Otherwise I'll look at the holes and take my best guesses.