DIY tool for rear main seal installation?

[ryan7662]

Hi, I'm replacing the 1 piece rear main seal on a 351w I'm swapping into my 95 gt. The otc 7786 tool is $100 something bucks so I'd like to avoid having to buy it. My first question is is there a simple homemade tool or method for ensuring the seal is driven to the correct depth and not damaged? I've never had to do this so I'm at a loss here sorry if this is a simple problem but I don't want to screw this up.

Also I'm also going to get a repair sleeve since I did find a slight groove on the crank that was made by the old seal. I see where I can order the repair sleeve installation tool for around $30 it looks like a white plastic disc. Does anyone know how this tool is used and can explain it to me?

Lastly I was going to get a teflon seal from autozone since I heard they are the best. I also heard that I should install it dry and not oil the mating surface between the seal and the crank. Is that correct? Also should I use rtv or something between the seal and the cap? Thanks for any help on this guys I'm probably gonna pull all my hair out if I have to tear the engine out because of a leaking rear main seal.

 

[revhead347]

You don't need a tool to the rear main seal, it's super easy. It has a lip to stop it at the proper depth, that's also not an issue. You shouldn't use any rtv on it. Just install it try. You just tap it in with a small hammer. Take a light grit sandpaper, and sand the surface of the crank where the seal touches it. It needs to have a fresh bite surface for the seal to break in. Put a little oil around the crank to lubricate the seal. Not sure what you are talking about with the front seal. You shouldn't need a repair kit on that either. Just sand the balancer a little, and replace the seal. On an SN, the front main seal is pressed in through the back of the timing cover, so you have to remove it to push it out.

Kurt

 

[ryan7662]

Sorry Kurt I must've misstyped somewhere I know how the front seal goes on thats no biggy. So I just gently tap the rear seal on with a rubber hammer until it stops? And you say you don't think the groove on the crank would be an issue? If not then that's $50 bucks I'd save by not having to get the sleeve and sleeve installation tool so if I don't need it then cool. Thanks for the help Kurt.

 

[Chythar]

Wouldn't be easier to drop the transmission rather then pull the engine? Just support the front of the engine when you disconnect the tranny and you should be fine. I used the old rear main seal to tap in the new one, just use light taps all around to get the seal in as flat as possible. If you push in the seal at an angle, you can warp and stretch the seal and it'll start leaking again.

Hard to tell about the groove. I think Kurt was thinking the groove was on the front of the crank, not the rear. Any damage to the crank surface can wear out the rear main seal faster. If the groove is more than a light scratch I'd use a sleeve just to be safe. Think of it this way: if you don't use the sleeve, you might have to replace the rear main seal again soon. How much is your time worth to you? How many rear main seals will you have to replace before you use a sleeve anyway? I see it as cheap insurance.

 

[ryan7662]

Yeah I think I need to sleeve it the groove is deep enough for me to feel it with my fingernail when I scratch it. Oh and this motor isn't in the car yet I have it on a engine stand right now. I'm getting ready to assemble it and check for pushrod length right now. Thanks Chythar

 

[revhead347]

If it's getting assembled, I just put it around the crankshaft when I drop it in. A little groove is normal. You'll have to use your discression on whether or not you need a sleeve on it.

Kurt

 

[ryan7662]

So Kurt you mean it'd be okay to just slide the seal around the end of the crank then bolt the cap on and that'd be okay? If so that sounds a lot easier then tapping it in.

 

[revhead347]

Absolutely. If the crank is out of the engine, just slide it around the crank. In my honest opinion you don't need a sleeve, but I haven't seen the groove. I would just sand down that crank surface a little bit, clean it up really good, lubricate it with some oil, and then put the seal on it right before you drop it in the engine.

Kurt

 

[ryan7662]

Absolutely. If the crank is out of the engine, just slide it around the crank. In my honest opinion you don't need a sleeve, but I haven't seen the groove. I would just sand down that crank surface a little bit, clean it up really good, lubricate it with some oil, and then put the seal on it right before you drop it in the engine.

Kurt

Yeah I think I'll take a little emery cloth to it and see if it polishes out before getting a kit to sleeve it. It's a slight groove my fingernail barely catches it when I scrape my finger across it. If it doesn't come out and still looks troubling I'll sleeve but after inspecting it further it appears to only be a slight scatch like Chythar was talking about. I'm almost positive it'll polish out with some light sanding. Thanks again Kurt

 

[revhead347]

If it's just a slight groove, it's not even an issue. It doesn't even have to polish out. Just so long as the metal roughs up a little again.

Kurt

 

[Zero Signal]

There will always be a groove on a motor with over 50k miles. I've had good luck with the cheap/pliable Felpro factory replacement seals on grooves that I thought were pretty deep. What's more important is setting the seal flat, but it's pretty much guaranteed if you feel it bottom out against the block. Sleeving can be kind of tricky with getting it on straight and not ruining it, hence the tool. So I usually try the seal first before bothering, but I've never had to do it on any of my vehicles.

 

[Rick 91GT]

If the crank is out I like to install the seal on there as well, just do all your bearing seating and thrust measuring before you put the crank/seal in the motor, I have found it slightly effects the measurements.