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My Dragon Datsun 521

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I enjoy your threads Daniel because of the information and detail but mostly because you work your trucks.  Even if they are missing doors they are put to work!  LOL

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Your fenders are looking great.  Mine need some work so I need to pay attention to your posts.

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After getting the inside of the left fender primed, I noticed some areas that did not get primer in to them with the spray gun.  Next time I have some primer mixed up, a paint brush will get these areas.



I have a small garage. Good thing I like Datsuns.  Here I am getting ready to work on some Doors.



This is the garage looking in.



This is a picture for two metal saw horses I have with some plywood on them.  My Dad made them, years ago.   I put some plywood on them, and have a nice bench.



I clamped this board on one of the rafters in the garage.



OK, this picture turned sideways, top is to the left.   Note the hammer and punch to the right side of the picture.


This is the top vent window screw hole on a 521 door.



This is that screw hole on another door that is damaged


By placing the punch on the damaged parts around the screw hole, I made it a lot better.




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Dragon also needed some more work on the right side of the radiator support, below the headlight.  With the lower grill rail off the truck for painting, it is pretty easy to work on this area, and most of this area is just flat.  However, looking down you can see where the support is bent in, above the front cab mount on that side.



This is just a piece of steel, I am using the straight edge on it to show the gap where the support is bent in.


I drilled this 3/8 hole, in one of the lowest spots in the core support.


The piece of steel I used as a straight edge is then bolted to the core support, the ends of the steel bar on high areas of the core support.


This is the back side of the core support, showing the hole, and a bolt.  Notice it is located in a thicker part of the core support, on the cab mount bracket.  The bolt, nut, and washers are a 3/8, grade 8.  I tightened the bolt snug, and pulled the dent in the core support against the flat steel bar.


I then used these hammers and a punch on the back side of the core support to work more dents out of the core support, where the steel plate was against the core support.  I also moved the plate around the bolt, to get to different areas of the core support.


Using a punch on one low spot.  I did take the tire off on this side, and a also drilled a second 3/8 hole below the first one.


That got a lot of the low area worked out, but not all of it.


I then put two 1/4 spacers on each end of the steel bar to give me more distance to "overbend" the core support.

Just a close view of one spacer.  This one is copper, it does not need to be.  A thin piece of wood would also work.


This is checking the flatness of the area after pulling it with the spacers under the steel bar.  I then checked the fit of the lower grill rail, sorry, no picture, but it was good enough.


Then I welded the holes up, using some 3/8 plugs.  More details later.

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Wish you were closer I would let you hone your body skills on my 520.  you make it look easy.

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i have plenty of my own Datsuns I need to get work done on.  It would be nice to be able to paint in the winter, but I would not like doing body work in the summer, in Arizona.

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AZhitman has an AC in his garage.  Maybe he will let me do the metal work in it.  I have a swamp cooler for mine.  LOL

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It has been a while since my last post, May is a busy month.  I have been working on Dragon, mostly a little bit of time here and there.  I did some metal work on the fenders, doors, test fitted headlights, and other minor stuff.   
This is what I am doing to the left door. the left door had a crack by the upper hinge, and several mirror mounting holes, and a fair amount of rust.

This is the hinge crack.  After cleaning the area of paint, primer, and rust, I put some bolts into the hinge mounting holes.  this is to prevent weld spatter from getting in the holes.  I also one of the bolts to bolt a piece of sheet metal to the door, this is where I attach the welding ground clamp.
I did some short welds, and let the metal cool.
Then I wire brushed the welds.
More welds, and wire brushing.  I did this until the whole crack was welded.
Then I used a small angle grinder to grind down the welds, to start,
This is after the angle grinder.
I lost the picture, but after using the angle grinder, I used a 3 inch cutoff disk on a small die grinder to grind then top of the welds some more.
Then I used an air power die grinder with a flat disk to finish the welds some more.
and then I used a 3M clean and strip disk to finish the welds completely.


These two holes were filled with plastic filler.  I decided to patch them with some 3/8 metal plugs I have. 

I put the door on a bench, and blocked the window frame up until this area was level. Then I set the metal plugs over the holes.


I did a short tack weld on one edge of the plug.

That pulled the opposite side of the plug high.  I held the plug down with a punch.

Then tack welded the opposite side of the plug.

Then I welded completely around the plug,

nd finished the welds.

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Wow nice work. keep it up.

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This is some work I have been doing on a dent in the left door.  It is in the style line of the door, near the front of the door.  It is very difficult to get a hammer behind the metal to pound it up.  It would be nice to have a stud gun, to pull the area up, but I do not have that tool.  I did pull the deepest area around the hole, by drilling the hole, and using a bolt, and a bar of steel, same way as I pulled some dents in the radiator support, post 204 on this, above.


I took a a piece of 20 gauge sheet metal, and put two 3/16 holes in the center of the strip of metal.  I bent the piece of metal into a flat bottom "U" shape, and then plug welded the bottom of the "U" to the low spot of the dent, in the door.

I then punched two holes into the legs of the "U" sticking up.  Then I used a slide hammer, and a nail to pull the dent up.

A farther out picture of the slide hammer.  I started with this slide hammer, but soon got a bigger slide hammer to pull the dent.
I finally got this area almost high enough, but I need to weld the holes shut again.

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Daniel your tool making creativity astounds me.  Nice work!

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To repair the hole I put in the dent to pull it, I put another 3/8 plug in the hole.


Then some short welds to hold the plug.

Then I ground some weld off of the hole plug, but not all of it.  This area of the door still needs a lot of work.

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Around the end of May 2018, I stopped work on Dragon, because it became apparent Dragon was not going to be ready for Canby. I decided to put a L-20-B engine in Ratsun, this truck.  http://community.ratsun.net/topic/30606-my-ratsun-datsun-521-now-with-l-20-b/
I did not make it to Canby with that truck either, I really should have made the decision to work on Ratsun about two weeks earlier,
These pictures are some of the work I did on the doors of Dragon, in May, but did not post them until now.
Before this picture was taken, mirror holes were patched, and the area was metal worked to reduce the amount of filler needed.  The primer was allowed to cure for a day, hen the door skin was cleaned and then sprayed with PPG DP40LF epoxy primer.   The primer was allowed to cure for a day, then I used a marine epoxy from Tap plastics, and fiberglass as a filler.  That was sanded down
Fiberglass filler has a lot of pinholes in it.  I do have some polyester body filler, but my catalyst was too old to use.  I need to get some fresh paste catalyst.  But there is more than one way to deal with that problem. 
Sanding the fiberglass down removed some epoxy primer next to the fiberglass areas.  The bare metal needed to be sprayed with epoxy primer first anyway.
A word on polyester body fillers.  Polyester resin is hygroscopic.   That means it absorbs water.  Depending on how old the polyester filler is, the humidity, how long the can has been left open, it can actually absorb enough water to make clean metal it is applied to rust under the filler.  Having Datsuns long enough to do repairs on the same sheet metal years later, I have found rust under polyester body filler applied to bare metal.  So, the first step I try to do on bare metal is clean it, and spray with at least an epoxy primer, or if a large area, I will use a rust preventive wash primer before the epoxy primer.  The epoxy filler I use does not absorb water.
A closer view of the pinholes in the filler.
I also stripped all the old primer and paint off the interior of the door.
Paint mixing tips.  I end up mixing a lot of small quantities of paint.  I use 6 OZ yoghurt container to mix paint in.  The container has a 5 in the triangle recycling symbol, and a PP below the symbol.  I board horses, and a lot of food supplements people buy for their horse have small measuring cups in them.  I use the small measuring cups.  This particular primer, mixes at a 1:1 ratio.  One measuring cup of primer, one measuring cup of activator.  Notice the two strips of masking tape on the paint can, it keeps spills off the side of the paint can.  I also went to a craft store, and got a box of Kraft sticks, or Popsicle sticks to stir the paint with.
This is the door interior sprayed with the PPG 1791/1792 wash primer and activator.
The the inside of the door sprayed with PPG DP40LF epoxy primer, with PPG DP402LF activator.RtinDP40LF.JPG
Hinge surface sprayed with primer.
door catch side sprayed with primer.
Bottom of door sprayed with primer.
This is just another picture of the door interior, either with flash on the camera, or not. 
And then I sprayed paint on the inside surfaces of the door with paint, Axalta Centari Nissan code 558 Dragon Green.  Axalta is the new name for Dupont.  Old Dupont codes still work as I am writing this, that color code is 31025.





I also painted the window frame

When I was done painting, after letting the paint cure for a little while, I moved it out into the afternoon sun to help cure the paint.

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Wow man very nice.

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What he said ^ :cool: 

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I am trying to improve my results painting car parts.  I have painted the inside, and window frame of the right door, but now I am working on the outside door skin, the area most visible.  I have done metal work, and primed the outside of the door.  I lightly sanded the door outside, and found some low spots.  If you look down from the lock cylinder, below the bottom style line, you can see two slightly darker spots.  These spots are low.
This is inside the door. the felt pen marks are on one of the low spot on the outside of the door.
I put a spoon dolly on the high spot inside the door, and used a punch and hammer to move the high spot toward the outside, where the low spot is.  The spoon spreads the force of the punch out over a larger area, and reduces the damage of the punch on the bare door skin.
That did not move the metal much, I then used some pieces of sheet metal to concentrate the force of the punch to a little smaller area.
For your information 22 gauge sheet metal, two sheets.
There was still a few very shallow low spots in the door.  They were filled with fiberglass and marine epoxy, and that was sanded down.  Then resprayed with DP40LF epoxy primer, and then some surfacer.  Then I sanded the door again.
The the bare metal spots were spot primed again with DP40LF.
Then the door skin was sprayed with a surfacer again.


The sanding, and spraying of the door skin was Thursday June 28, in the evening.   Friday morning, I sprayed a very light guide coat of some old lacquer I have, and then set the door out in the sun to dry.

Later on Friday, I sanded the guide coat down, and decided the door was good enough to finally paint.  But first, I sprayed a thinned final coat of PPG DP40LF epoxy primer, because there were again a few small spots of bare metal, some surfacer primer, other spots where I sanded down to previous coats of epoxy primer, and a few small spots of the lacquer guide coat. 

another picture of seal coat on door.

Friday evening, I sprayed Dragon Green Centari, Datsun code 558 on the door. 

This picture was taken Saturday morning, I moved the door out into the sun, to help cure the fresh paint.  This was not the best looking paint job on the door, I sprayed the paint a little dry, and it has some slight orange peel in it.

Saturday evening, I put some insulation in the door.  This is some silver light weight insulation I found at Home Depot.  The insulation comes in a roll, with this label on it.

Close view of the insulation label, with more info.

This is the spray contact cement I used to glue the insulation inside the door.  You spray the contact cement on both surfaces you want to glue together, and let it dry for 5 to 10 minutes, but not longer than 30 minutes.  Spray inside the door surface, and then spray on the side of the insulation that goes against the door skin.

Cut the insulation to fit inside the door.  I cut two pieces of insulation.  There is this brace inside the door, one piece of insulation below the brace, the other above the brace.  Before to do body work on the door, this brace needs to be reglued to the inside of the door skin with some seam sealer.  If this brace is not glued to the door skin, the door skin is not supported in the middle, and is very difficult to sand because the door skin bends under very light sanding pressure. 

Another picture of the door skin brace.

Back to trimming the insulation.  Round off the corners to match the contour of the bottom of the door.  this insulation just cuts easily with a pair of scissors.

Fit the insulation inside the door before applying the contact cement to the inside of the door, or the insulation.
Sorry, no pictures of spraying insulation and the door skin with the contact cement.

The contact cement pretty much sticks as soon as the two pieces with the cement applied to then make contact with each other.  I sprayed the area of the door skin below the brace first, and the piece of the insulation that fits in that space first, and carefully slid the insulation in place through the window slot.  As long as the place you touch the inside of the door without contact cement applied to it, the sprayed insulation does not stick.  Once the insulation is in place over the correct area, press it down, and it is stuck to the inside of the door.  Then I applied contact cement to the inside area of the door above the brace, and put the second piece of insulation in the door, and presses it in place.


This picture was taken after the contact cement was applied, and the insulation put in place.


The last thing I did Saturday night was put the door hinges I had previously painted on the door, and put the door on the cab.

This guy was in my yard early this morning.

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Happy Independence day, 2018, USA!


The last Dragon picture in the post above showed the right door on the cab.  There were no windows, run channel or lock parts in the door.

I like putting doors on the cab without any guts in them, the door is much lighter, and easier to hold in place.  I bolted the hinges on the door, and set them approximately in the center of their adjustment on the door.  Keep in mind the adjustment of the hinge on the door affects up and down of the door, and in and out of the door. 

The door weather strip is in the cab.  I just held the door in the cab opening about where is should be, pushed the leaf of the door hinges close to the door post on the cab, and reached in through the window opening, and started the bolts that hold the door hinge to the door post.

Then I more carefully held the door to where I wanted it to be, and tightened the hinge bolts in the door post on the cab.

Before I put the hinges on the door, I chased the threads on the door hinges with a 5/16-24 tap, and wire brushed the threads on the stock bolts, and cleaned up the washers.  


Yesterday, I put the guts in the door.  This is brief explanation, door disassembly and reassembly are on page 8 of this thread.



Steps to door assembly, from my memory.

Put new window run channel in the rear, and top of the door frame.  Put new run channel in the wing window.

Cut a piece of string longer than the distance from the top of the window frame to the bottom of the door twice.

Loop the string on the bottom of the sliding window, tape it to the window.  Lower the sliding window into the door by holding the bottom of the window toward the front, and after the window is in the door, rotate it upright, and move the rear of the sliding window into the the run channel at the rear of the door.

Slide the wing window into the door, at an angle and guide the wing window channel over the top front corner of the sliding window.  As you slide the wing window into the door over the sliding window, guide the front of the wing window into the door frame.  When the wing window is in place, check that the sliding window stayed in the run channel both front and rear.  Then put the four screws in the top front angled door frame in to the front of the wing window.  Do not put the two screws that hold the bottom of the wing window channel. 

Pull the sliding window close to the top of the door with the string.  If the window does not move fairly easily, figure out why, and fix it.

Tie the sliding window near the top of the door. 

Slide the window regulator into the door, through the rear hole in the door, on the inside.  The arm of the window regulator fits in between the inside door panel, and the front window run channel.

Slide the roller on the regulator arm in to the channel on the bottom of the sliding glass.

Move the crank end of the window regulator around until the crank post goes into it's hole in the door.  The four screw holes that hold the regulator to the door panel will probably not line up.  Put the window crank on the regulator post, and turn the crank until the four holes line up, and put the four regulator screws in the window regulator.

Remove the string from the window, and make sure the window rolls up and down.  Do not roll the window down too far.  The regulator arm will come off the sliding window channel, and the regulator arm may go down far enough that the crank gear loses engagement with the regulator arm. Crank the window up.  Now you can put the two screws in the front sliding window run channel.  Roll the window down and up to make sure it moves without too much force.


Now the lock mechanism.

Clean the 45 year old grease off the lock mechanism, and put fresh grease on it.


The lock mechanism will have either two or three main parts, depending on if you have a later 521 or an earlier one.  Earlier 521 trucks did not have a pull knob by the back of the sliding window to lock the door from the inside, slightly later trucks got the hump for the pull knob, then the knob was added to the door, and finally later, a fourth access hole was added near the bottom rear of the door, to make installing the bell crank for the pull knob easier.

Slide the lock mechanism onto the door by folding it, and compacting it in the rear upper hole on the door.  Do not force it together, it will fold easily on to itself without bending anything.

Put the two screws loosely into the forward inside door handle release.

Put the door latch mechanism in to the rear surface of the door, and put the three screws in snugly to hold this part.

If you have a pull door lock interior knob, make sure the two rods going down to the bell crank do not cross each other.  The door latch is outside of the sliding glass, but the pull knob is inside the sliding glass.  The bell crank is under the glass to get around the glass.

Put the rod for the interior door lock knob through the hole in the door, and screw the plastic pull knob on the rod to hold is in place.  Put the two screws in the bottom bell crank.  Some doors may only have one screw for the bell crank.

Check operation of the door lock mechanism without actually closing the door.  You cannot lock the door unless it is closed, or the mechanism thinks the door is closed.  To fool the mechanism into thinking the door is closed, on the rear outside of the door, there are two gear teeth on the door latch.  Rotate the gear teeth toward the outside of the door.  you should be able yo lock and unlock the door with the pull knob, or  by pushing the interior door latch handle forward if you have an early door, without a rear lock pull knob.  If the door lock works, put the outside door release handle on the door. 

After installing the outside door release handle, unlock the door, and pulling the outside release handle should release the gear door latch.  Reset the door catch gear closed, check the inside door handle releases the door catch gear.

Tighten all the screws in the forward door release handle, lock mechanism, and bell crank if your door has it.

Put the lock cylinder in the door, from the outside.  Slide the retainer fork over the lock cylinder. 

There is a small lever on a short rod on the lock mechanism, that goes over the end of the lock cylinder.  put the lever on the lock cylinder.  Finally put the small "hairpin" over the lever on the lock cylinder, being very careful not to drop it in the bottom of the door.

The actual door closing fit should be checked with the door catch removed from the rear door post.  The rear catch is not used to align the door.  The door hinges should hold the door in the proper position.  After the door position looks good, holding the door closed with one hand and sliding a dollar bill between the door and weather strip can be used to check and finish door alignment.   When the door fit looks good, and the dollar bill has some drag all the way around the door, put the door catch back on the rear door post, and adjust it's location to fit the door.  After putting the door catch on the door post, recheck door operation.  If you adjust the door fit too close to the cab, it will put more stress on the door catch parts, and the door handle will be harder to operate.  Try to avoid this.

Edited by DanielC
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I have been doing work on Dragon, just not posting it.  Here is some of the work.  the left door weatherstrip was pretty bad on Dragon, torn and painted by previous work.  I found some other old door weather strip, and cut pieces of it to patch the left door opening on Dragon.  I also straightened some of the aluminium door sill guards.



The OEM screws were most probably rusted, and lost, and the screw holes in the sill guards were way oversized.  Not the best picture, but I got some new stainless steel screws, and some brass finishing washers to make up for the holes being oversized.



The left door that was on Dragon has a lot of rust on the bottom.  I had also obtained another 521 left door, but is also has rust on the bottom, but not as bad.  Dragon OEM door has the green paint on it.the other door has the light blue paint.  both of these door need a lot of work.



This is the door that originally came on Ratsun.  It is an earlier "push door handle forward to lock" door, and not a pull lock knob door like the OEM door on Dragon.  But there is a lot less rust damage and mirror holes to repair on this door.  In the effort to get a left door on Dragon quickly, I am going to put this door on Dragon.


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One of the minor issues with Dragon is the speedometer is not reading, and when it was reading, it was way off.   I think I had a speedometer pinion for a 4.875, green, 23 teeth.  

There is a 1974 620 truck at Sherwood Pick-n-Pull, and it had this red 20 tooth speedometer pinion in it.  My Datsun competition catalog says this pinion is used with a 4.11 rear axle ratio.

I am looking for the correct speedometer pinion for a 4.375 rear axle ratio.  This pinion may not be what I need.  

But since I have put a L-20-B engine in one of my other 521 trucks, I think I would like to put a 4.11 rear axle in that truck.  Did Nissan put 4.11 rear axles in 1974 trucks?  




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Only the '79 4 and 5 speed 620s got the 4.11.


Best way I've found is to figure out how much the speedometer is out and know how many teeth are on your pinion gear. I have 205/60R14s on my 710 which came with tiny 165R13" and then I switched from a 3.70 to a 4.11 differential. The speedo is out to lunch. By using mile markers (always 1/10 mile out) and those residential radars around playgrounds I found that to go 30 my speedo has to read 33-34MPH. So that's just over 10% too fast. This is on a Red 20 tooth pinion gear. 22tooth / 20tooth = 1.1 or 10% slower. Thanks to Charlie69 I now have a 22 tooth in my 710. Unfortunately I had to take the transmission out to fix something but it's together just needs me to fill with oil and I'll get a check on the new speed reading... probably tomorrow. I'm sure this will fix it.


So if you are reading 48 when really going 50 then you are 6% slow. Here the speedo needs to speed up by 6%. If you had a Red 20 tooth then 20 / 19 = 1.052 or 5.2% faster. That's a close as you will get. With a 19 tooth pinion your speedo is now within .7% or 0.21 MPH out at 33MPH... shrug.

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Mike, If I put the rear wheels up on ramps, do you think it will get the back of the transmission high enough so a lot of oil will not come out of the speedometer pinion hole?

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Ha ha I tried that. The first time I lost half the oil. Second time I caught half the oil in a container. I could not get it high enough in the back and still get in close enough in the front. But this is in my driveway. You have a tractor? with a lift... probably will work. The pinion is pretty low on the back of the transmission and it's half filled.

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What is the purpose of raising the truck with the pinion out?    Just got back from California and pretty tired so please help me understand.


I hope this helps Daniel.




I have 17 & 18 tooth pinions.  I will look to morow to se what I got the last time I went to the junkyard.  Might have another number will post tomorrow.


In the mean time you can order the pinion drive gear from here and install it in your sleeve.






Edited by Charlie69

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My thought is that by lifting the back of the truck, the transmission oil would run to the front of the transmission, and away from the speedometer pinion hole.

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