320 Newb Posted October 3, 2016 Report Share Posted October 3, 2016 This weekend I'm pulling out a J15 to replace the rear main, lower pulley, and oil pan seals. Any words of wisdom? Lessons learned? Tips? Quote Link to comment
datsunrides Posted October 3, 2016 Report Share Posted October 3, 2016 Rear main is a rope seal, which means you need to pull the crank out to properly fit it. Make sure to soak it in oil first, seat it per the manual, and don't cut the ends too short on either cap or it will leak. Don't forget to replace the side seals in the cap. Front seal and oil pan are simple. If you feel like trying, they do make a Chinese finger type tool you can use to pull the rope seal in without dropping the crank by tugging on it and rotating the crank. I've had some success with those on early Chevy motors, so it is an option. 1 Quote Link to comment
320 Newb Posted October 6, 2016 Author Report Share Posted October 6, 2016 Does anyone offhand know the nut size on the lower pulley on the J15? I'm assuming it's the same size as the J13. Quote Link to comment
wayno Posted October 6, 2016 Report Share Posted October 6, 2016 Does anyone offhand know the nut size on the lower pulley on the J15? I'm assuming it's the same size as the J13. Mine is 1 1/16ths inches 1 Quote Link to comment
320 Newb Posted October 6, 2016 Author Report Share Posted October 6, 2016 Good to know--thanks Wayno! I assume all the engine hardware is SAE? Quote Link to comment
wayno Posted October 6, 2016 Report Share Posted October 6, 2016 Good to know--thanks Wayno! I assume all the engine hardware is SAE? I don't know, I just took 3 sockets out to the J15 engine I have(1", 1 1/16th", 1 1/8th") because you were asking, and the middle one was the winner. I have never worked on that engine other than installing it once in the 520 kingcab and getting it running, I soon changed my mind about the engine, yanked the cab off and dropped it on the 720 4X4 frame, then changed my mind again and dropped it on the 1986 kingcab frame it sits on today as a 520 ute. 1 Quote Link to comment
320 Newb Posted October 6, 2016 Author Report Share Posted October 6, 2016 Wow Wayno she's a beaut! The seal that's got me a little freaked out is the rear main rope seal. This is straight from the J15 manual: 2. Thoroughly clean groove in oil seal housing of crankshaft rear bearing; place ofl seal in groove with finger and thumb. Using an oil seal replacer Guide), lightly tap with a hammer until oil seal is installed correctly. Trim seal flush with ends of housing block. Install oil seal in rear bearing cap as above. Everything else I read tells me to soak the rope in oil for a couple minutes first and cut the rope seal a hair long using a guide. I've also read recommendations to put a dab of RTV on the cut ends of the ropes. Has anyone done rope seals before on a J13 or J15? I'm scared I'm going to pull the motor, do the fix, put it back in, just to have another leak. Or a worse leak. Quote Link to comment
Stoffregen Motorsports Posted October 6, 2016 Report Share Posted October 6, 2016 Rope seals are not fun, but when done properly, they do work great, and for a long time. Is the one in the kit graphite coated? I've installed lip seals in Austin Healeys Sprites, MGB's, MGTD's, Sunbeam Alpines, and I bet one of those kits will fit the J series. Really though, if you can find someone to help or figure out how to do it, rope seals really are very good. Quote Link to comment
zed1 Posted October 6, 2016 Report Share Posted October 6, 2016 The rope seal was part of the gasket kit I provided to the engine rebuilder. His comment was "the rope seal will eventually leak". https://www.flickr.com/photos/53116286@N07/albums/72157624963500879 Keith Quote Link to comment
wayno Posted October 6, 2016 Report Share Posted October 6, 2016 Rope seals need to be installed by someone that knows what they are doing, I did mine on my R16 in my Roadster, I screwed it up. When you tighten the crank mains it pushes/compresses that rope deep into the groove and pulls the ends down into the groove creating a gap on both sides no matter how much you tapped on it with what you have, as the "oil seal replacer guide" is a specialty tool that 99 percent of us don't have. I figured it out and my engine didn't leak oil, but most on here would shake their heads if they knew how I did it. 3 Quote Link to comment
Stoffregen Motorsports Posted October 6, 2016 Report Share Posted October 6, 2016 If this engine builder has ever done an early SBC, he should know that there are tricks. One trick is to leave the seal a little long on all the ends and it will squish into each other as the bearing cap is torqued. As far as that tool, you can use the crank itself as that tool. Please Wayno, tell us your story! How did you do it? 1 Quote Link to comment
wayno Posted October 6, 2016 Report Share Posted October 6, 2016 If this engine builder has ever done an early SBC, he should know that there are tricks. One trick is to leave the seal a little long on all the ends and it will squish into each other as the bearing cap is torqued. As far as that tool, you can use the crank itself as that tool. Please Wayno, tell us your story! How did you do it? Lets just say my rope was in three pieces instead of two pieces, and it was squeezed in there tight by the time I finished. 2 Quote Link to comment
320 Newb Posted October 6, 2016 Author Report Share Posted October 6, 2016 Any suggestions on how much extra to leave on the ropes when cutting? 1 Quote Link to comment
Stoffregen Motorsports Posted October 6, 2016 Report Share Posted October 6, 2016 Here's an article on Hemmings website that may be helpful - https://www.hemmings.com/magazine/mus/2009/03/Rear-Main-Seal-Repair/1782923.html 2 Quote Link to comment
Little Hustler Posted August 14, 2021 Report Share Posted August 14, 2021 I just received a complete engine gasket rebuild kit for a Nissan J 1500 Engine Nissan Forklift overhaul gasket set from E bay by aalift(1323) It comes with a 1 piece rubber seal, round. approx. 65mm, 2 9/16 in id. Seems to match the rope seal size, diam but is thicker . approx 12 mm thick. Double lip. Has number M 67 85 13 and logo JAGO. Is this a rear replacement seal? The rope seals are a pain and I hope someone has come out with a rubber one, But I don't remember this in my previous rebuild kit. Is it some sort of front seal? Or will it work in the rear if the space is machined wider for it? The other gaskets seem high quality. Datsun 1965 L-320 PU J1500 engine rebuilt. Gasket set for spares insurance. 5 Speed custom built tranny. Weber Carb. Double Valve Springs. Cam ground for more duration & lift. MSD Ignition + more... Elliot pthermit@hotmail.com 2 Quote Link to comment
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