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My Dragon Datsun 521


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It was a day after Christmas miracle!

Oregon is going to raise the rates for car registration January 1, 2018.  I decided to do the insurance and registration on Dragon before year end, before the rates go up, and as a little extra motivation to get Dragon on the road again.

I was in and out of the Oregon DMV office in 12 minutes.

 I have kept my 66 registered since I purchased it about ten years ago. $19 and change every year is worth not having to go to the MVD to get it registered to drive it.  All I have to do to drive it is to get online and record my insurance information with MVD and drive.

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Door assembly, continued.

Start the two inside vent frame screws.  Do not tighten them yet. 


You need to put these four screws into the vent window first.  The bottom screws are a #8 sheet metal, or tap screw.  The top screw is a #8-32 machine screw.  These four screws are about a 1/4 long. 


I got some stainless steel screws to replace the rusty screws that were originally in the door.  Put these screws in, and tighten them.  If you turn a sheet metal screw backwards, it will find then old threads, and when you feel it drop in to the old you tighten it, and not cut new threads, and weaken the threads as much. 

Now you can tighten the screws in the bottom of the vent window frame.

Check to see if the window rolls up and down, and then roll it up to the top.


Now you can reinstall the lock mechanism.  The inside door open handle holder sits in this position inside the door.  Notice it is above the rod that goes back to the lock mechanism.  It can pivot below the rod, but you cannot get the screws in it, if it does pivot.


Slide the forward door control in the back hole of the door, and then the lock mechanism.  This is an older 521 door, without the inside lock knob.  Later lock mechanisms have an inside lock knob, and have two extra rods that go toward the bottom of the door, near the back of the door.   These extra rods can be folded close to the forward door control, and the whole assembly can be slid in the door.  Make sure the two rods that go to the bottom of the door do not cross each other.

Just another picture of sliding the lock mechanism in the door.
Another picture of sliding the lock mechanism in the door.


Put the lock mechanism into its hole in the back of the door.


This is the outside of the back of the door, lock mechanism sitting in the door.


Start the three screws into the lock mechanism, do not tighten yet.

Lift the forward remote control into position, remember it has to to be above the rod that goes back to the lock mechanism.


Put the screws into it, again loosely.

You can now tighten the three lock mechanism screws in the back outside of the door, then tighten the two screws that hold the remote control to the door, near the front of the door.


This is the lock cylinder hole.  Notice the three notches on the lock cylinder.


Notice the three tabs on the lock cylinder, they fit the notches in the door.


Put the lock cylinder in the door.


Slide the lock retainer clip on the lock cylinder.  The clip is about half way on in this picture.  I put some grease on the retainer, to make assembly, and disassembly easier. 


The cylinder retainer clip is just pushed all the way on the lock cylinder.  Notice a rod hanging down below the lock mechanism.


This is the lever on the rod, that goes over the lock cylinder.


The lever is just slid over the end of the lock cylinder,


And the clip is slid on the end of the lock cylinder, holding the lever.

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  • 2 weeks later...

Dragon has had a hard life. It has been in two front end collisions, and was parked next to a rental truck, that turned coming out of a parking spot, and the rear of the rental truck raked the right door, and right front fender.  This picture shows the gap between the radiator support, and the headlight surface on the left front fender.  The right was worse, it had an even bigger gap.


In May of 2013, I made these plates out of 1/2 inch steel.  They were cut with an Oxy-acetelene cutting torch, then crudely finished with an angle grinder.  They go inside the headlight bucket.

This plate goes on the outside flat surface of the radiator core support, over the headlight bucket. You need to remove the lower grill opening rail to put this plate on the truck, but if you are pulling on the core support, you need to take the lower grill opening rail off anyway, to straighten or replace it.  Use a spot weld saw to remove the lower grill opening rail.


Here are the plates in the position for the left headlight bucket.  Turn the plates over, and they fit the right side headlight bucket.

This picture is the bolts to clamp the inner and outer plates together.  Also in the picture are three pulling eyes I made.  Once the plates are in the headlight bucket, and bolted together, you can use the three longer bolts to position the pulling eyes where you want then.

I parked Dragon close to a post on a carport, parked my Ford Aerostar behind Dragon and chained them together with the trailer balls.
Then I used a cable hoist to pull on the radiator core support.


Another picture of pulling the headlight bucket forward.  I did a couple of pulls on each side of Dragon.  After each pull, I would take Dragon back into the garage, unbolt 16 bolts, and try the fit of the fender on the truck.  I think I did at least two pulls on each side of the truck.


The center of the radiator support was also pushed in.  I made these two brackets that attach to the center of the radiator support using the radiator bolt holes in the core support.  This was an easy pull to do, I just pulled until the part of the hood catch on the hood lined up with the hole for the hood latch on the radiator core support.



The nice thing about working on a pickup is you can store stuff in the bed, but that means when you get the pickup running, you have to find another place to store the stuff that was in the bed.  This picture was taken after the bed of Dragon was mostly cleaned out.  I still had to find a place for this transmission.

This stuff was also in the bed of Dragon.


This is a spot I cleaned out in the bed of another 521 I have.


This is where I put the transmission,


Then I put these extra fenders back in the bed of the 521 in the garage.  This 521, I call Dragon Two needs the floor replaced.


The next six pictures are after I took Dragon on a short test drive.






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At first I thought you made those plates as spacers to fill the gap between the fender and radiator support. Nice to see that I was wrong.


I've done repairs like that. Sometimes (if the vehicle runs) I'll put it in gear and back it up to give it a hard pull. That can be scary...

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I contemplated tying it to a tree and backing up method, but that is a little too uncontrolled.  By using the hoist, I can watch, and listen to stuff as is moves.  I can stop the pull if I hear anything ugly, like metal ripping, or spot welds being broken.


There are two stages of metal deformation when a stress is applied to the metal.  Elastic deformation, and plastic deformation.  Elastic deformation happens first, and then springs back to the original shape, nothing moves permanently.  Valve springs undergo elastic deformation. 

Plastic deformation happens when all the elastic deformation is "used up".   You are now changing the molecular structure in the metal, and it returns to a new shape when the stress is removed.  The amount of force to move metal once it is in the plastic deformation stage actually drops.  At this point, it becomes very easy to damage things.


I am going to park this link here for now.


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On Wednesday, Jan 14, 2018, I decided to do some preventive maintenance work under Dragon.   I had two of the ramps in the picture, and a friend gave me two more when he moved to a much smaller place.   
It is a good thing I like working on Datsuns, a full sized vehicle really does not fit in this garage.
Decided to change the oil in the rear axle first.
The drain plug has a 1/2 inch square socket.  Being on the bottom of the truck, crud builds up in the plug, preventing the square drive from going all the way into the socket.  I cleaned the crud out with a broken part of an old test light.
Then I used a 1/2 inch breaker bar to remove the plug.
And let the old oil run into a empty oil bottle, with a funnel.
The drain plug has a magnet on it, to catch metal bits, and keep them out of the bearings and from getting in between gear teeth.
While the rear axle was draining, I cleaned the drain plug.

Next, I drained the transmission.  It has a square drive socket like the transmission.  The oil came out of the transmission much quicker that it did out of the rear axle, rapidly overfilled the funnel, and ran on the floor.
After cleaning up the mess, I cleaned the transmission drain plug.  I also put a little bit of thread sealant on the threads of the plug.  then I put the drain plug back in.

The transmission fill plug has a 11/16 square drive, I used a long wrench to remove that plug.
This is a little plunger pump I used to pump the new transmission oil, GL-4, yellow metal safe gear lube into the transmission.  I have this pump from changing the lower unit gear lube in outboard engines for boats.
This is the discharge end of the hose on the oil pump in the fill hole in the transmission.


This is the gear oil I used in the transmission.


You pump oil into the transmission until it started to run out of the fill hole.  Remove the fill hose, and put the plug back into the side of the transmission. 

Then I put the drain plug back into the rear axle, and filled the rear axle in the same way as I filled the transmission, and put the rear axle fill plug back in the rear axle, and then time to go to work.

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Thursday, the next day. I flushed old brake fluid out of the hydraulic clutch master and slave cylinders.  This is a handy tool I use for that.
I opened the bleed valve on the slave cylinder just a little, and pushed the black rubber boot over the bleed valve.
And then by pushing the clutch pedal, it pumps fluid into the cup.

I pumped the clutch pedal just enough to almost completely drain the clutch master cylinder reservoir. but not enough to pump air into the cylinder.

I used paper towel in the cylinder to clean the inside of the master cylinder,

This is the paper towel that was used to wipe out the clutch master cylinder.
When you are pumping fluid through the master cylinder, and slave cylinder, it will save you a lot of time if you do not ever let the master cylinder reservoir get empty.  If it does get empty, you pump air in to the system, and you have to completely pump the air all the way through the system to get the air back out.  This is not so difficult on a clutch system, but on brakes, there is a lot more lines, and slave cylinders for the air to get pumped into.
I pumped this much old fluid through the system,
This is some of the the old fluid and trash pumped out of the system.   
Then I refilled the clutch master cylinder one last time, and pumped the clutch pedal just enough to bring the fluid level in the master cylinder to the full mark, and put the cap back on.
Somehow, when I put the five speed transmission in this truck, I did not put the boot that goes over the clutch throw out lever in the transmission before I put the transmission in the truck, this part.

I cleaned the area on the transmission where it goes, and removed the slave cylinder,

And then by using a big 18 inch Cresent Wrench, was able to move the throwout lever enough to slip the lever boot into the hole in the bell housing.  No pictures of using the Cresent Wrench to do this, I was more concerned with having to hold the wrench, and not slip.  Then I put the slave cylinder back on the transmission.
This is the brake fluid I used, the fluid in the green labelled bottles.
This is what the fluid looks like in the clutch, and brake master cylinders.

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After making the above post, I had a little time before I had to go to work.  I got these parts, Nissan calls then "aprons" out, and sorted through them for one to put on Dragon.  I picked the top one, they all need body work, and painting.  The second one down, although it looks better, it has cracks in the flange that bolts to the corners of the front fender.  It was hung on Dragon, just with four bolts.


Earlier that week, I got some wiper blade refills, but on Monday, I put the wipers on Dragon.


After putting the wipers refills on Dragon, started to bleed old brake fluid out of the brake system.  You start with the wheel cylinder farthest from the master cylinder.  I bled fluid all the way through, then as I was tightening up the bleeder valve, it broke.


I am pretty sure I have some new rear brake slave cylinders somewhere, that I bought in 2005 or so, when you could get them at Nissan dealers.  I looked for them, but did not find them.  I have another project truck green 521, Dragon Two.  I took the part i need for Dragon off Dragon two, and cleaned it up.  Then I put the bleed valve in the good part.  I used teflon tape on it.  I know the threads do not do the sealing on the bleed valve, but the teflon tape seals air leaks when you are bleeding the slave cylinders, when pedal pressure is released.

Before bolting the bleeder "Y" to the slave cylinder in the backing plate, I attached the brake line.  The fine threads (3/8-24) on the flare nut are hard to start without cross threading, if the "Y" is rigidly mounted on the slave cylinder, and you are trying to hold the brake line in the correct position, and angle.  Once the brake line is attached to the "Y" put the through bolt, with a copper washer on each side of the "Y" on the slave cylinder.

Tighten the through bolt, with a 9/16 wrench.  Remember, body parts on a 521 are imperial measurement.

Then tighten up the flare nut that holds the brake line on the "Y".


As I was moving Dragon around the yard, over the last few years, I had to add brake fluid every so often.  I found the flare nut on the "Y" above was barely past finger tight, when I took it apart.  Maybe that was my slow brake fluid leak?

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Need a little help, I need to identify this transmission.  I believe it is a FS5C71B.

The speedometer in Dragon reads too slow, by about 11 %, I think.  The speedometer pinion currently in the transmission is a green one, 23 teeth, for a 4.875 rear axle.  I think I need a 21 tooth purple gear, for a 4.375 rear axle.  Part number for the pinion, 32703-86401.



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I actually bought that transmission from a local Datsun dealer, in the 1970's.  Nissan had only been putting five speed transmissions in Z-cars for a short while, I am not sure you could get a 620 truck with a five speed.

It was the lowest first gear ration five speed I could find.

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  • 1 month later...

I have been kind of ignoring Dragon while working on a L-20-B engine I got from a Pick-n-Pull in February.  I have been starting it, and driving it a little, every week or two.  Cars are much happier if you do not let let then sit for a long time.
Anyway, I Needed to adjust the choke cable in Dragon.  I started it, drove in in my garage, and started to work on the cable.  the I heard a water leak, down by the alternator.  I finished the work on the cable, and let the engine cool a little.  I got a light, and used a pressure tester to put some pressure on the cooling system.  I found a bad lower radiator hose.  Then I drained the coolant, and removed the lower radiator hose.


This is the bad hose. 


I have kept old radiator hoses, and also have some new, and newer ones.  I got my box of radiator hoses out of storage, and got a much better lower radiator hose. 


Last December, I had put the wipers, and other stuff back in the cab of Dragon.  I could not find the wiper motor that came out of Dragon, so I put another wiper motor in Dragon.

Why am I telling you this?

Because in the bottom of my box of radiator hoses was sitting the wiper motor for Dragon.


Anyway, I put the better radiator hose on Dragon, and coolant back in it, pressure tested the cooling system, and put Dragon back away.

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I took Dragon for a short drive yesterday afternoon.  I got a few bales of hay from a neighbor.  Dragon still needs some painting, and after moving the hay, I took the headlights, and front fenders off the truck, and the the left door.  There is some bare metal on the door post, and rust under the door hinges.   Since the door is off, I also removed old paint, primer, and rust off the rocker panels.


Door post.  Sorry, this picture is rotated 90 degrees left.

Rocker top.
Rocker bottom.

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