J13 rear main seal

[boxboy]

Okay gentlemen,

 

I received my gasket kit in the mail this week. Got a complete set with everything even though I may not need it all. Anyway, I took a look at the wax impregnated two piece rear main seal and thought, "no way! Someone has to have a better way figured out to seal up the back of this engine." So I am putting it out there to see if anyone knows the trick. From what I hear, you have to drop the crank to get at this seal anyway. Since I don't know yet what the back of this little engine looks like, does anyone know if there is some aftermarket fix? I noticed that Rock Auto has a Timken product advertised on their site as a rear main seal, but it looks like a transmission seal to me.

 

Interested to hear if there is any info out there on this one.

[wayno]

Hi there Boxboy, Do the two pieces that make up the rear seal look like rope? wayno

[boxboy]

Yes Wayne. They are like a black wax impregnated rope. Two pieces.

[wayno]

My roadster had that rear seal also, I messed up the first try, they have tools that you use to beat that seal into position that are U shaped. What happened to me was, I cut the seals to match the groove, put them into position and tightened down the crank, I was wondering how it worked out, so I removed the crank and couldn't beleave my eyes, when I tightened the crank down it pushed the seal farther down in the groove and the seals were at least an 1/8th inch short of touching each other, and this was in the garage, upside down on an engine stand, with no rods connected. If there is a differant seal to put there, no one has told me about it yet, but your in the right place to find out. How about it guys, is there a aftermarket seal that is easier to use than the rope? wayno

[ggzilla]

Simple, just don't "cut the seals to match the groove". Install it and it won't leak.

Newer Datsun engines uses a one-piece rear seal, but the two-piece works fine usually.

[wayno]

As I recall, there was way too much rope(1/2" or more for each half), it had to be trimmed, it was getting between the main bearing cap and the block mating surface on the successfull second time around. wayno

[boxboy]

So to answer the question as to if it is possible to replace without dropping the crank I am hearing a "no." That sucks. I don't need a complete tear down and rebuild. Just a few new gaskets and a clutch. Was thinking that if I had the clutch and the pan off I might as well be safe and do the rear main as well while I was in there so close. But I don't want to have to drop the crank to do it.

[ggzilla]

I think you can do it without removing the crank. But you have to loosen the crank enough for it to drop down a bit.

[wayno]

Hi boxboy, Is your rear seal currently leaking right now? If it isn't, don't mess with it! wayno

[boxboy]

Good question Wayno. The answer is I don't know. I have so many other leaks I don't know where stuff is coming from. I know the tappet covers are leaking, the oil filter housing is leaking, and possibly the fuel pump as well. So I bought the entire kit because it was about as cheap as buying piece by piece. My plan was to change all of the easily accessed ones and go from there. But as I need to pull the engine someday in the near future to change the clutch, I figured that would be an opportune time to do those harder to reach places like the rear main. I know some guys have just said "let it leak" rather than change it out. I may have to do the same.

 

Incidentally, I have no book for this engine. I am nervous about pulling parts off to replace gaskets and having issues. For instance, is there something connected to the oil filter housing that has to be lined up just right, or can I just remove it, clean it and reinstall? Where can I find torque values for that sort of thing?

 

Other questions are, do you use any high tack or high temp silicone (hondabond) when installing gaskets, or put them on dry? The Honda motorcycle engine required nothing, but I have a feeling it was much more precision than this engine. Gasket material was higher quality than cork/rubber anyway. Any advice appreciated. I am leaning toward leaving the rear main alone for now.

[wayno]

Hi there boxboy, if your rear seal is leaking there will be oil coming out of the trans./bellhousing breather hole, now if there is oil everywhere I can see that as a problem on finding all the leaks fast. So fix the ones that are obvious, LIGHTLY pressure wash it with degreaser, you do not want to make new holes by blowing the old gaskets apart, and keep your eye on it everyday you drive it. Do you have a lot of engine blowby? wayno

[boxboy]

I don't know what you mean by "blow-by" Wayne. I don't have any smoke at all, and everything seems to run real nice. Just a really bad clutch, and I do get a "diesel" once in a while when I shut it off. I have too much oil all over to tell where things are leaking from. Already replaced the rocker cover, so I know its not from there, and I can see that it is leaking from the oil filter housing, and pretty confident that it is coming from the tappet covers as well. Could be my clutch is getting wet from a rear main leak I suppose. I don't put on a lot of miles, but I haven't notice a lot of oil use in the 500 m or so that I have driven it since I bought it, so I am guessing just leaking. I did do a wash, but just used a garden hose and some simple green with a lot of brushing and scrubbing. I didn't want to blow anything apart with a power washer.

 

Like I said I would like to get my hands on a manual for this engine before I start pulling parts off and replacing gaskets. But when I do I guess I will start with the top down. Fuel pump, oil filter housing, tappets etc. Not sure I will tackle the head gasket if I don't have to. Then I will see where I am at before pulling the engine and doing the clutch and we'll see about the rear main.

[Gary]

its technically possible to swap out the crank seal without removing bearing caps completely, but you need mad skillz to pull it off

 

ive been through it too :( i dropped the crank enough so the pistons were still in their bores which saved some messing about

 

i think i found the manuals on olddatsuns.com if you want to have a hunt about on there

[wayno]

Hi there Boxboy, blow-by is when you remove the oil filler cap on the valve cover and a mass amount of air comes out while the engine is running, sometimes it will coat your hand with oil. A little amount of air coming out is normal, but when it comes out like an air blower on full, well, it will blow gaskets out and cause leaks everywhere, it's too much air getting by the rings, "blow-by". My truck diesels everytime I shut it off, I don't notice anymore because I let the clutch out while in gear to kill the engine automaticly/subconsciously anymore. When you get to the clutch I guess you will find out if the rear seal is leaking, as the whole inside of the clutch housing will be soaked with oil if it is. There sould be a small hole in the front bottom center of the tranny bellhousing right next to the rear of the oilpan, if the rear seal is bad, oil will drip out of that hole everytime. wayno

[boxboy]

No, no blow-by.

 

I'll search olddatsuns.com for the manual.

[Craig Hughes]

Hey Boxboy, I have a model 520 series Datsun pick-up sevice manual from Nissan Motors Co.,LTD.,Tokyo, Japan, that covers everything with numbered figure pics and spec sheets.I didn't realize this was such a dificult book of info to come up with. I'm going to look into scanning stuff on to Ratsun if it would be helpful, but I'm not good at that so keep looking elsewhere if your in a hurry!

[boxboy]

Thanks Craig. I actually have the 520 service manual. But I know there are also J13 specific rebuild manuals in existence too. I was looking for something a bit more step by step than the service manual that is readily available. To me that one is incomplete and confusing. For instance, I can't find any torque specs for fuel pump bolts or oil filter housing bolts etc.

 

I believe Zed1 said he had a book that he bought from ebay europe or something. I did find one for a J15 forklift motor, and that may be as good as I will get. I would assume torque values to be the same, but perhaps not valve adj. specs and fuel system specs. Don't know. I am used to more of a Haynes/ Chilton type thing which are not available for the J13.

[boxboy]

By the way Craig, I drive a Datsun with a J13. I am never in a hurry!

[wayno]

Hi there, I have the chiltons(#5790), I did my roadster tranny with it, but it had no referance on how to replace the rear main seal, it tells you how to do a lot of things, but not that. It's good that there is no blow-by, you can rule that out for causing seals to leak, so they are just getting old, like me, when your 50+ years old, sometimes things just start to wear out. wayno

 

 

[zed1]

The Datsun Engine Manual is for the J13/J15&J16. The manual is at the engine rebuilder, but when I get it back I'll be glad to copy the index. Then you can tell me what page(s) you need copies of.

Keith

[boxboy]

Sweet Keith. Thanks. I am moving really slow now, like molasses. Budget has been passed and I haven't started tearing into her yet. But since I have your contact info, I will let you know when I get there. Thanks again..

[Charlie69]

The Datsun Engine Manual is for the J13/J15&J16. The manual is at the engine rebuilder, but when I get it back I'll be glad to copy the index. Then you can tell me what page(s) you need copies of.

Keith

 

 

It would be cheaper and more usefull to scan the pages in to the computer then you can email the images to anyone you like.

[Craig Hughes]

Good stuff Zed1, I guess if Boxboy needs those extra details not covered in the service manual, I will also because I'm in the middle of a complete J13 rebuild on 1 motor and will turn around and do it again with the one I pull out and swap.By the way Boxboy, where did you get your parts?, I'm getting mine from a place called Powerhouse Engine Components,Inc. in Bakersfield Ca. who have bearings aswell, but my mechinic/shop instructure bud whos walking thru this proccess in the high school autoshop(8 bays-4 big roll-up doors!) says I'll need one over standard pistons so I need to see if the supplier can get those or what you'll recomend. I'm not much of a talker but this website talkin topics is sure encouraging me with my prodject possibilities I hop Boxboy is getting the same! Thank you folks, much appreciated.

[boxboy]

I haven't had to get anything yet except for the gasket kit. I got it at Northern Auto parts online. I think they are in Iowa or something. I know you can get stuff for the J15 through the forklift dealers that doesn't pop up on the automotive sides radar anymore. I will check out Powerhouse though. At this point I don't want to do an entire rebuild since my engine seems to be running strong. I just need to stop the leaking and get a new clutch in.

 

This site has encouraged me a lot when I wanted to just punt and sell the thing. Lots of guys on here with a lot of knowledge. Ratsun Rocks!

[Craig Hughes]

Hey Boxboy, here is there #, 661-861-0125 to help your contact of Powerhouse, good shopping!