MigsD16

I'm finally able to continue my D16Y7 engine rebuild and it's time to install the oil pump, front & rear seals, etc. I'm a little confused with instructions I've read (both Haynes, & FSM) with regard to pressing seals into the housings. I'm not talking about attaching the housing to the block, I'm asking about pressing in the actual seal with the spring in it. Should I apply a thin layer of RTV or oil to help it slide into the housing or just press it in dry?

The confusion began when I read in the Haynes manual to use a thin coat of oil, but I'm not sure if it's referring only to the inner part before sliding it onto the crank or also the outer part before pressing it into the housing. If you could help me figure this out, I will appreciate it very much. It seems most people install it dry after cleaning it well, but I want to make sure I do it the best possible way. I also don't want it moving around and leaking after a few thousand miles.

Thank you!

TomCat39

Proper procedure by the Factory Service Manual (Helm's Manual) is to oil the inner lip of the seal that rides directly on the shaft. The outer is supposed to be bone dry and perfectly clean, both on the seal and the seal housing the seal slides into.

Now I have seen and I personally use Flange sealant on the outer edge of the seal. Not only does it help maintain a seal but it also prevents the seal from being able to spin in the housing causing a leak later on down the road.

The downside to using the anaerobic gasket maker is that it's a real bitch to get the seal back out later when you have to replace. And does add some time and effort into cleaning the housing surface for the new seal.

Also I use a Molybdenum Grease on the inner lip of the seal instead of oil. Molybdenum is a serious friction modifier for metals and I hope that it prolongs the life of the seal over just using oil.

This is my practice, but it has not passed the test of time by running 20 years to see the outcome. A few years in without problems so far.

I'll let others speak to their methods of assembly for the main seals.

MigsD16

I appreciate the reply very much, as always!

PyroProblem

A little oil or even silicone spray will let the seal slide easier into the housing. It won't spin. Its a snug fit.

TomCat39

I suspect this aspect may depend on if the seal is OEM or not.

The front main seal on my wifes car was spinning freeling in the housing and that's where it was leaking from.

I replaced with the OEM seal, but added a tiny amount of flange sealant as added measure.

Age might allow it to shrink also, not really sure. But after seeing it first hand.... I'd rather have the added cleanup with added peace of mind that it's only going to leak from the crank shaft after it wears out, not anywhere else before then.

MigsD16

I stopped by the dealership today and picked up the front and rear engine (crankshaft) seals. I've put too much time into this to use anything other than Honda parts. I also decided to use a thin layer of black RTV on the outside of the seals and pressed them in with my bench vise. For the front crank seal I used an old Blackhawk 40x 3/4" drive socket that was just barely smaller than the seal, it worked perfect. And for the rear seal I used the old rear seal to press it in and it worked great. I left a 0.025" gap between the seal and the seat of the housing, since it calls for that in both manuals I'm working from. Speaking of which... what is the need for that gap?

Both th seals are nice and snug and I know they will last, since they are Honda parts. While I was at the dealership I picked up some of he smaller specific shaped coolant hoses since they had them in stock. No point in skimping now and I might as well save myself a trip.

Now I just need to put the oil pump back together and get it all connected to the block. I will take some pics and post them up later.

thank you for the help and support!

MigsD16

In case people are curious, the manufacturer of the Honda OEM Front and Rear crankshaft seals is NOK. The smaller front seal was $8, and the larger rear seal was $20.50. The goop on the inner areas of the seals is some kind of silicon grease that was already on it when I removed them from the Honda packaging. It probably helps keep them fresh. I cleaned the outer edge with 50% isopropyl alcohol real well before applying the black RTV. I wanted to make sure it formed a nice seal up against the housing. I'm hoping this build will last a while if you can't tell.





The gap was about twice as thick on the original seal, but I made sure it was factory spec and perfectly even all the way around.


I also picked up a new oil pump spring from the dealer as well as new o-ring. I showed the rotors to my machinist as well as my mechanic, and they both assured me they looked great. They were well within spec (about mid range) when measured.


To clean the inside of the oil screen real well I used Berryman Chem‑Dip, that stuff is amazing to me. The outer oil pump rotor looks like it has a groove in this photo, but it's more of a burnished area than anything. The rotors are well within spec and surfaces are nice and smooth. I think I'm ready to put it all together.

If you see anything that doesn't look right or can think of things that an amateur like myself may have overlooked, please let me hear it. This is the first time I've rebuilt an engine and I want to do it right.

TomCat39

I couldn't really tell you except maybe so there is room to push the seal in a little further next time if there is a groove on the crank shaft.

That's the trick I've heard from both experienced builders as well as from my factory trained Honda tech I buy parts from at times.

MigsD16

Damn, maybe I should have seated it all the way then... my crank isn't super worn where the old seal was touching, but it definitely has a groove. My fingernail doesn't catch on it and it looks a lot worse than it is, but hopefully this seal is in a little further than the last one. I don't want any leaks after all this work. It's kind of too late now to try and reposition the seal, if needed. I made sure it wasn't going to move in the housing.

Front crankshaft


Rear crankshaft

MigsD16

Ok, so I know I said the groove is small, but how deep does it have to be to cause problems? The reason I ask is because my new seal sits right where the groove is. The seal is fixed to the housing, so is there anything else I can do at this point to try and keep it from being a problem? Should I sand it a little with some 400-600 grit wet/dry or anything like that? I've read that using an emery clothe is a good idea, but should I do more than that?

TomCat39

You said you couldn't catch it with a nail so you will be fine.

The grooves I see leak are 1-3mm deep and a fingernail definitely catches in them.

Your grooves look more like a polished spot more than an actual groove.

MigsD16

Excellent, this is what I was hoping to hear. This isn't my first engine build, but it's the first I've one by myself and I am incredibly thankful to have you help me through the process.

TomCat39

You know, it's not really me helping per say. I'm more just getting you beyond your internal "concerns".

Really we are our own worst enemy by doubting ourselves and abilities.

I'm just now finally learning that lesson. I've wasted a couple of grand prematurely due to paranoia. My old motor ran fine yet the piston slap caused me to worry enough I dropped 450 on a motor and paid someone to drop it in as well as swap the clutch that was still operating fine etc.

Now I do those jobs myself but still think about the pain of learning through the school of hard knocks.

My current D16Z6 has severe piston slap, but still puts it down. Teaching me just how far these motors go before they truly crap out and how much money I've wasted.

PyroProblem

From what ive seen, when those types of seals usually leak where they make contact with the crankshaft, not really the outer diameter. The little spring inside the seal helps keeps a snug fit around the crank surface. After a long time, the spring becomes weak and/or the rubber starts to become brittle and doesnt seal anymore. Any kind of positive crankcase pressure can make these seals leak as well.
Looks good so far!