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Bruiser! 78 620 KC project


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  • 2 weeks later...

Well, last night I set out to replace the steering box seal as the girls have a horse show this weekend and I don't want them stranded with a broken box.


I bought a "front end repair kit" at Harbor Freight, one of the pitman arm pullers was just the right size.




However, being a Harbor Freight tool, the amount of force I was willing to put into the tool was not enough to pop the arm loose.  I tried wedges between the tool and the steering box and also tried hitting the pitman arm with a hammer and a long screwdriver from the top of the engine compartment.  Nothing would make it budge and I didn't want to overstress anything inside the box by going caveman on the thing.  So I cleaned up the everything as good as I could with a rag and got out the propane torch.  After a few minutes of heat application to the pitman arm around the steering box shaft, I re-hung the puller, cranked the bolt, and the arm came right off.




The seal took a while too, but eventually I persuaded it to come out with a flat screwdriver and some careful prying motions.




New seal in place and seated with a deep socket.




I reconnected the arm, torqued the giant nut, filled the box with 90W, cleaned up, and went to bed.


This morning there was not a drip in sight.  VICTORY!!!

nice work. Where can I get that seal? Mine is leaking too and I didn't know there was a seal under there

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  • 1 month later...

I had some free time over Christmas break so I decided to replace the windshield in the truck.


I got a brand new windshield from ProSource Glass International and a new seal from Route 66 Restorations.  They both say 271 so I guess that's a good sign.






I started by fitting the seal to the windshield.  I was a little surprised at how generous the seal is compared to the window.  It's been a while since I've done one and thought I remembered having to kind of stretch the seal.  Not necessary.  It actually seems like there is extra.





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While I'm at it, I have a much nicer dash that I wanted to swap in so I removed the nasty looking old one.




I expected the wiring of the new dash to be obvious except for the aftermarket stereo so I took some photos of the various connections as you never know where they may have chosen to splice in for power.




Next I removed the old glass and seal and unfortunately found considerable rust probably 50% of the way around the windshield frame.






That would help explain why it leaked so bad.  Hard to get a good seal against a crumbly bubbly rusting surface. 



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I took a stiff wire brush and eliminated all the loose stuff. 




Then I went shopping for a can of POR15.  The local O'Reilys and Napa did not carry it but Wesco did.  Man that stuff is expensive! 




Also noticed that the lower right drain was filled with sealant so I cleaned that out.




Next I masked off the windshield frame and painted on the POR15 with a foam brush.  I extended the tape a little past the old paint line.  This isn't going to be pretty but I'm going for preservation here, not car show points, since I don't know when I will get around to painting this truck for good.




I learned my lesson last time and pulled the masking tape while the paint was wet.






This should keep the rust at bay but the surface damage has been done and I'm doubtful I will get a good seal without application of liquid sealant when I'm done.

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While  I had the truck all apart I wanted to get rid of the old 4 post door mirrors and I had a nice set of 720 mirrors in the garage I thought might look nice.  I also grabbed a z-car rear-view mirror with the day/night toggle to replace the crusty 620 one but then realized the 620 mirror mount is different than the 510/z-car mount.








Found a nicer stock mirror while collecting the rest of the dash parts and also found a nice little 5spd shift knob.




Had to let the POR15 dry overnight so I started prepping the dash for the swap.  I set them side by side to compare wiring which was a good thing because I found the new dash had modified defrost ducts (to clear the V-8 kit firewall hump?) and was missing a few things like fuse box, vent actuator supports, and a few other wiring things...  Hopefully I didn't miss anything - and fingers crossed that everything works!




I was scratching my head on this one.  There is an in-line fuse under the right side of the dash.  The new dash was missing the fuse and holder so I grabbed the one from the old dash.  In the process I found that the fuse was broken.  The radio would cut-out when I'd go over bumps.  I wonder if the radio power went through that fuse.  Looks like at some point in time there was a little issue here...  The whole thing was covered in electrical tape to hold it together.



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Next day Brenda helped me put in the windshield.  This is so much easier with an installation buddy.




It was a bit of a struggle and the string I used was too small in diameter but in the end, we won!




Here is the new dash set in place.




Almost done.  I prefer the black dash but it is nicer to look at one little crack instead of giant chunks ripped out of the pad.  The door panels will go back on after I plug the holes in the door from where the old mirrors mounted.




Brenda helped again with the wiring test.  Reconnecting the battery for the first time after wiring work can always be exciting but nothing bad happened.  I didn't have right blinkers but that turned out to be the flasher.  The blinker indicators and seat belt sign in the dash don't light up but there are 5-6 wires under there still that are not connected because it's not obvious where they go.  I was very surprised to hear I now have a seat belt buzzer!  While checking everything out I noticed I had one brake light out and one backup light out so I replaced those bulbs while I was at it. 


Definite improvement overall.

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I was really hoping to get the new rear-end in over break as well but I was unsuccessful finding some 5x4.5 (5x114.3) steel wheels nearby that I could swap on for the remainder of winter.


But I do at least have some wheels on the way from Japan to fit once the swap is done.  Hopefully the oxidation is only skin deep.



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  • 4 weeks later...


So Corey and I headed off to school a couple days later (first drive) and I thought I could smell some hot wiring.  Gave it a sec and didn't notice any smoke.  Wasn't getting any better or worse.  Assumed it was maybe some dust/patina/residue from the 30 year old harness.  Decided to soldier on only to realize I had no wipers.  So we turned around, went back home and took Cooper instead.


So, out comes the dash again.




There were a couple connections I wasn't able to make and figured perhaps those had something to do with the issue.  I decided to swap the 79 dash pad over to the 78 dash frame just to eliminate any wiring issues.




For those of you that don't know, the dash pad is bolted to the frame and is easily removable.




The Nissan p/n labels on the two harnesses were different.




Switching back to the '78 frame also allows me to skip having to deal with the surface rust on the '79 frame.




Here is the '79 pad ready to accept the '78 frame.




Didn't think much of it at the time but see how the wiper switch on the '78 had flat prongs and the switch on the '79 had round prongs?  That's why I had no wipers.  I couldn't connect the switch.  I had just forgotten about that one...




Everything back in its place




Let's try this again...




Much better.  While it was out, I also took the time to TR3 to the top of the dash frame.  Looks so nice!







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Spent some time re-wiring the stereo as well.  It used to cut out when I'd hit bumps (which, in a lowered 620, is ALL the time).  Thank goodness for the internet!  So fast and easy to find useful information!  I containerized everything too to make it easy to take the console in and out while I'm working on the truck.



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A few days later everything seemed to be working well and the truck was reliable again. 

Oh crap!  Don't say the "R" word...


I drove from work to school to pick up Corey to take him to driver's ed and when I turned onto the street the school was on the truck died.  I coasted to a parking spot on the curb and tried to re-start.  Nothin' doin'.  We made some quick re-arrangements for my wife to take him to class and I stayed and tried to figure out what was going on.  I could crank over easy and after pumping and/or holding down the gas pedal, I could smell fuel so I assumed spark must be the issue. 


I pulled the distributor cap and found that the contactor in the center of the cap was just a black nub.  Aha!  I figured I'd clean it off and re-gain contact to the rotor.  When I touched it it literally just crumbled to pieces. 




Well that's not good.  I called around and found another cap and rotor.  I also had my wife swing by the house and get a few tools as well as a couple spare distributors.


When she arrived I tried the cap and rotor from one of the spares and found no improvement.  They were from later model nissan electronic distributors though so I figured maybe the '78 with the remote ignition had its own special set.  I went to two different auto parts stores to get the cap and rotor needed, came back and tried them and no luck.  At this point it was dark and raining and I figured fine.  The truck can stay overnight at the school and I'll come back in the morning with a few more tools, a volt-meter, and a coil.  Called Jeff too just to make sure I was on the right track.  He's always a good sound board for diagnosing electrical issues.


The next morning Brenda and I dropped Corey off at school and proceeded to work on the truck.  I started by verifying I had 12V at the coil.  It was above 12V (didn't think much of that at the time) so I knew I had power.  Then I checked for spark at one of the plugs and verified I didn't have any.  I assumed it would be the coil or the ignition at this point.  I checked the power again and found I had 16V at the battery.  16V!  Crap!  That's probably it.  I bet the alternator is overcharging the battery and fried the ignition.


Assuming that was the case, I swapped in one of the spare matchbox distributors and a "blaster" coil.  Turned the ignition to verify spark and it looked like we were back in business.  Finished putting everything together and sure enough, the truck started right up.  Note old distributor is still connected and sitting in the fender well.  Didn't know how to unwire it from the factory harness and figured I'd solve that issue once I got home.




Ride home was a little unnerving - between the timing being off (and so being even more gutless than usual) and the worry about 16V frying this distributor too before I got home.  But alas, I made it without issue.  I checked the battery again when I got home just to be sure I wasn't doing something wrong.  Over 16V!




The truck was parked again...


Last weekend, I was going to swap the alternator but before doing so - figured I should check a few more things.  First, I checked two of our other cars and they both read above 14V just sitting in the driveway.  Well, maybe the volt-meter is bad.  I borrowed one from work and put them both on the battery.




Sure enough.  The other voltmeter says it's fine.


Next step, replace the battery in my voltmeter.  Then check again.




Great!  Now the truck is fixed, and the voltmeter is fixed, but my theory for why the truck stopped working is out the window.  The distributor cap was obviously shot but replacing it didn't help.  Did the coil die?  Did the ignition module die?  I don't much feel like swapping back in the old components to diagnose further you know what I mean.  Any theories?


Only thing left to do was to set the timing.  I put a light on it but couldn't find a mark on the pulley so I just kept rotating the distributor to advance as far as the adjustments would let me.  It is clocked exactly the same as the distributor I took off.  I half wonder if the reason the truck seems so gutless is that the timing is still excessively retarded and more distributor adjustment would let me bring it in spec.  Hard to tell with no mark though.  I'll look at it again some day but for now, I'm back on the road and just in time.  Teaching Corey to drive stick and this is a perfect vehicle to start in.  We went out in Brenda's Lexus the first time and that was pretty stressful every time he'd pull up to a curb in a parking spot.  CLUTCH CLUTCH CLUTCH!!!!

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After the dash work was done I knew the guy that ended up with the tan cab from the parts truck wanted a tachometer so I sold him the gage pod.  Then there was a classified on Ratsun for someone wanting the wiper delay.  I planned on offering the whole dash harness because I thought it was all integrated in there.  Turns out Nissan was really clever and they just made a subharness for the wiper delay.  The subharness plugs in to the standard harness in place of the wiper switch (with flat blade connector)








And has a pigtail with a round -pin connector that goes to the wiper switch.




So the key is that you have to have the wiper switch designed for the delay.  It has 4 positions (off - del - low - high) rather than the standard 3 (off - low - high)


After discovering this I kicked myself because I would have liked to have kept it but I'd already promised the sale so I went through with it.  I guess I'll be looking for a replacement now.  :confused:

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Oh yeah, also, while this was all going on, my wheels arrived from Japan. 




They surfaces were as rough as I had expected but what I didn't expect, was how bad the steel lug seats were!




Those will definitely have to be pressed out and replaced as part of the wheel reconditioning process.

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In other news...  It's always bothered me that the truck had no fuse box cover.  I found one on e-bay.  A whole NOS fuesbox actually.




Surprisingly cheap!  More surprisingly - from Greece of all places.  There are still a few Datsuns alive and well in Greece.  Must have been one of the rare Datsun friendly European countries back in the day.



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  • 6 months later...

I had to park Cooper this summer so I've been driving Bruiser allot.  It sucks!  It crashes over the bumps so hard it feels like something is going to fall off (me or the truck or both).  Jeff was bouncing up and down on the back and said I need new shocks.  Why not?  Everything else has been replaced - except those.  So I got some KYB gas-adjusts on Rock-Auto.  Started with the rears since I suspect those were the worse.






Oh man what a difference!  Every truck should have new shocks.  : )


No time for the fronts yet but they will come soon enough.

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Always maintenance with this one!


One of the right rear running lights went out a while ago.  Simple fix with a new bulb.  Well now the right rear brake and turn signals went out.  I started with new bulbs again but no difference.  Turns out it was the turn signal switch!  Fortunately I had one from the '79 and it plugged right in - except for the extra little pigtail.  But now I'm safe and legal again.









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This is coming along real nice. 


Replace the philips head screws on the top of your dash with hex head bolts. Much easier to remove with the windshield in.  Datsun Nissan 720s are hex head bolts.


What disc brakes and brackets are those on the rear end?

Edited by Charlie69
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  • 1 month later...

As previously reported, the exhaust on this truck was getting a little long in the tooth...


Well, obviously neglected, Bruiser decided to make his feelings known the other morning as the muffler finally let go and literally fell off the truck about a block from work.






I would say we probably exceeded the recommended life on this one.




Summit Racing to the rescue.  I found a 1 3/4" in and out muffler and got it on order.  The old stock outlet was only 1 1/2".  I was hopeful that the whole muffler was creating a bit of exhaust constipation as this is the most anemic L20B I've ever driven.




Got an appointment with A1 Muffler in Everett.  I highly recommend this shop!  Doesn't look like much but the guy knows how to do exhaust.




He tucked everything up so much higher than stock!  Looks super nice and sounds so smooth.  Amazing how it changes the whole feel of the truck after driving around with broken exhaust for a couple months and then ultimately a straight pipe for the last couple of trips.






Made Bruiser feel like a million bucks!  Or at least a pot of gold!




Double Rainbow!!!!




Yeah!  New exhaust is that nice!  : )

Edited by carterb
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  • 3 weeks later...

yeah dont cut those straps befoe you put those shocks in!!!!!!!!. BUT BUSHINGS ON LINE UP CUT ANS SHOOT IT THRU THE HOLE.

you said the L20 was weak. Sure the dist is timmed correctly?


Love the truck=Practical use,daily driver

I dont even drive my Rising Sun 510 its all 521 now and yellow one sold and dont miss it

Edited by banzai510(hainz)
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