My 1969 Datsun 521 kingcab diesel

[wayno]

I don't think so, it looks to be molded onto the shaft and the yellow geared shaft is a lot shorter than the black geared shaft, I did look at just changing the gear though, I heard someone else broke the gear trying to remove it.
The shaft/gear are held in the housing by a roll pin though, the issue is that the yellow color/gears are so rare, as far as I know right now only the 720 mileage option had them gears, it was the 720 with the Z20 instead of the Z24, not many of them around, and then how many 1985/86 regular cab/short box trucks with short shafts were made with a Z20 engine.
I might have found what I need, Crashtd420 on Ratsun offered to trade me what appears to be a long speedo housing with a yellow gear for my black one, it's slightly shorter than the black one in the transmission now(1/8" shorter), but I think it will work.

[wayno]

I received and installed a long yellow speedo gear/drive, the only difference I have seen/noticed is that at 70mph I am right at 2500rpms when before I was slightly over 2500rpms, with the black gear in the transmission it showed 28mph on the radar when my speedo showed 30mph, nothing has changed on that, I showed the same thing today with the yellow gear.
I did have to cut a new groove in the speedo housing as when installed the gear didn't engage the teeth in the transmission, but turned 180 degrees it worked fine.
The stock groove

The groove I made, I actually cut the groove slightly closer to the speedo cable connection(1/16") as this gear is an eighth inch shorter than the black gear

Until I take another trip and see what mileage it shows at 10 miles on the mileage posts I will not know how accurate the odometer is, to know if the mph is right I will need to pace someone that knows theirs is right.

[Laecaon]

That is where a smart phone would be good. You can get GPS speedometers for them. Fairly accurate on straight roads. My cars stereo tells me my speed via GPS, and its usually within 1to 2 of my actual speedometer.

Most new cars over report their speed. My car has a stated 3% error. The M3 version of my car has a 8% error. I once drove a Camry that said 35mph, but the radar said 31...

[wayno]

I have been driving this truck most the time now, I figured out how to start it the first try even when cold outside(above 45 degrees), for what it is I am amazed how dependable it is considering the starter is held on with one bolt and that turnbuckle that holds it up(the top bolt is stripped out).
I have noticed it is not so driver friendly when it is wet outside, even though I removed the 3.5 LSD and put in the 3.3 open diff it still spins out in first, second, and third if I give it too much pedal, but that is better than the ass end trying to come around making a left turn.
I still do not know if the speedo is correct, but I have went by several cops and none have come after me even though the speedo showed me over the speed limit a little.
I like this truck a lot, I would rather drive this than anything I own, it is fun to go thru the gears and a pleasure to drive on the freeway, that turbocharger is awesome, I need to find another 1985/86 Subaru XT turbocharger, it works great on this SD25 engine.

[wayno]

This truck doesn't start well when it is cold out, and when it gets near freezing it doesn't want to start at all, I was searching around and found a thread about Canadians starting their diesel trucks in the winter when it is below 0 degrees, they were always talking about an intake heater of some kind, I was thinking it was some kind of hair drier that blew hot air into the intake, well it turned out to be something else completely.
I have a block heater which works pretty well if I plug it in around an hour before starting it, but this will not work if I am some place that I cannot plug in say like on a trip where I might sleep in my truck at a rest area, so that thread interested me.
As it turns out I have an SD25 engine, Yanmar makes an air heater element that will actually fit in between my intake manifold and the throttle body that controls the injection pump, it will not fit on a SD22 engine, only the SD25 engine.
This is what the two different ones I bought look like.









I started the SD25 in the 720 this morning with it set up like this, it was 34 degrees outside and the neighbors roof still was frozen, the low was 32 degrees outside last night.





I cycled the glow plugs twice and the heater was on maybe 3 minutes, it did start right away but it missed a few times before smoothing out, but this engine has always started fairly easy, the 521 SD25 engine does not start easy below 40 degrees, but it is a lot harder to deal with as the piping is tighter and getting it apart and put together in the cold is a lot more difficult, especially when I needed to get to a job before it starts raining like what happened today, I just didn't have the time this morning and now it is 42 degrees outside, not cold enough for a test start to see if it actually will work this way instead of mounted under the throttle body.
Right now only one bolt and a turn buckle hold my starter on, to put the heater under the throttle body I will have to set up the turn buckle all over again, like with everything about this engine I don't want to mess with anything that might change the way things are working right now, it starts and runs great right now and to fix the top starter mount bolt I will have to remove the transmission or everything on the driver side of the engine to even access/remove the starter, except for it not starting easy when it is cold outside this truck runs great and I have a block heater I can plug in and an hour later the engine starts great, I want this other heater in case I am some where where I don't have a place to plug it in.

[DRIVEN]

Would it work any better if it was under the throttle body?

[wayno]

I expect that would be the best place for it, but as I mentioned I would have to take the chance of screwing up the starter situation, the starter is being held in position by the lower bolt, a turn buckle with an eye slid over the nipple on the end of the starter(see photo below), and a block of wood hammered in between the end of the starter and the engine mount bracket, if I take the turn buckle off the starter skips teeth instead while turning the engine over, and to extend that turn buckle setup I made I will have to buy more parts and hope it stays on the nipple like this setup has for quite a while now(over a year I think).
This photo is of a short eye piece placed on the nipple as an example of what I have in the truck right now so it will start.



This is what it looks like when I made it, maybe it could be extended an inch, I see some extra threads.



Here it is installed, it's in a really cramped place.



I worry that I won't get it installed properly like it is now if I take it apart, what if I tighten it too tight or not tight enough and something breaks, this truck runs so good right now that I don't want to do anything that could possibly change it right now, I have decided to wait till something breaks before I change anything, it is insured, the 520 is not insured right now, so I want to drive the 521 kingcab year round, normally I drive the 520 this time of year as it does start below freezing, but I cannot use chains on it if it snows because it is so low.

[DRIVEN]

Ahhh, I understand now. Not sure a description would have made sense without those pics.

[wayno]

I would have posted the photos yesterday but Postimage was not loading, all my photos were still there but I could not post any new ones.
It looks like I might be able to extend that jury rig bracket I made another inch, but I am kinda scared to mess with it, I really don't want to remove the transmission or pull everything off the side of the engine even though I have another reason to do that, as some day I need to remove the exhaust manifold to drill and thread it to except the EGT gauge probe as it should be before the turbo rather than after the turbo like it is now.
I just don't want to mess it up, it runs and drives so good right now, and it is raining a lot here now, I just don't like working on my vehicles in the rain unless I have to just to keep it on the road/in service.

[wayno]

OK, so this is what I did, first I mounted the Air Heater Element in line between the turbo and the throttle body, I used a cereal box material for gaskets when I mounted the fittings onto the Air Heater Element.



Then I mounted the relay on the firewall.



Next I wired the relay to the Air Heater Element and the Battery, I put a 40 amp fuse near the battery.



I also used the relay plug when I wired the toggle switch to the relay.



I then ran the wires into the cab(3 of them), one wire is the ground wire for the light telling me when the heater is on, it goes to the ground wire on the relay plug, the next wire goes from the relay plug to the toggle switch, the last wire goes from the toggle switch to a keyed power source, I wired it so when the heater is on the light is on but it is done in the switch, I used the window washer plug in my engine bay harness to power the relay, I did this because that plug has power with one click of the key, it also has power after the second click when the glow plugs also have power, I did it this way so I can warm up the Air Heater Element first, then turn the key one more click to power the glow plugs, then when the glow plug light goes out I can start the engine, then once the engine is running smooth I will turn the Air Heater Element off, the light is fairly bright(red).
The toggle switch and light are in the radio delete plate, the reason I put them there is because I had a radio delete plate with a hole in it for a toggle switch already, I just drilled another hole for the light, I put my good radio delete plate in a storage tub I have for plastic parts.



I started it once when the relay was wired to the battery and Air Heater Element, it was 43 degrees outside and it started fairly smooth, but I need to start it below freezing to know this is going to actually work this way.

[wayno]

I started this engine this morning, it was 34 degrees on my property in my back yard in the shade, there was ice on my windshield that was no where near melting and a half hour later it is still frozen, I powered up the Air Heater Element about a minute before powering up the glow plugs, then I cycled the glow plugs twice and then started the engine, it started right up without any issue, it missed a couple times and then ran smooth, I turned the Air Heater Element off right after it was running smooth, it has never started this easy even in the 40s and that block was below freezing as it was 28 degrees last night and the sun had not shined on the truck yet.
It warms up fast when it starts warming up, in the last hour it has warmed up to 41 degrees and the windshield is now melting and the neighbors roof has thawed also, but it was cold when I started it and everything was still frozen.
The Air Heater Element likely would work better under the throttle body as it is closer to the cylinders and the warm air doesn't have to get by/thru the cold throttle body/butterflies, cold turbo tubing to get to the cold intake manifold to get to the cold cylinders, I am positive closer is better, but when I started it today with the Air Heater Element where it is it started when I would not normally even tried to start it without plugging the block warmer an hour earlier as I have tried before in the 30s and could not get it started, this has made a difference for me.

[DRIVEN]

Great news!

[wayno]

I did a couple things to this truck today, first I pulled all the glow plugs and tested them, they appeared to be just fine, I cleaned them up and put them back in as the set I planned on putting in were shorter by an eighth inch, it didn't change how it started when cold without plugging it in or using the Air Heater Element, it missed a bunch of times for likely 5/10 seconds.
The second thing I did was make the radiator upper supports cleaner, the photos will show you what I mean, I did both sides.






I painted them but are going to let them dry overnight, I will install them between the rain storms tomorrow.

[wayno]

[Taterhead]

Sometimes it’s the small details. Looks good Wayno, as usual.

[wayno]

Today I found a radiator over flow container, I have always disliked what I have.





I checked for fitment of the container I found and it was too large, so I looked down in there and seen a 4" square hole just large enough to fit a B210 radiator over flow container, I tried before to fit it in there but I just didn't see any way to mount it, so I put the one in the photos above in.

Well this is what I did, I made a small bracket that I welded to the bracket holder, you can see one screw holds it on.



I put a piece of door weather seal at the bottom to keep the bracket from rattling against the radiator.



Here it is installed, it clears the fan by more than an inch and the radiator fins clear about the same, I like this much better, I drove it to the store and didn't hear anything rattling, so I am calling it good.

[wayno]

I drove this 335 miles today, the first half 75+mph, the return trip I likely averaged 70mph, I got around 30mpg(11.3 gallons, I think I topped it off better when I got home and filled it).
I was late getting out of the house, it took around 2.5hrs to do the first half, it was windy in Renton WA, the return home there was more traffic until south of Olympia, by that time I had got used to around 70mph and I just went 70/72mph the rest of the way home catching myself under 70mph several times, 2500rpms is 70mph, and 3000rpms is 85mph, most of the vehicles were in the left 2 lanes and they were going fast today, average speed for everyone was around 70mph everywhere, even north of Olympia where the speed limit is 60mph.
The 521 didn't have even a hiccup the whole trip.

I think I need to notch in the frame in the back, not as large of a notch as the 520, but I bottomed out a couple times and the bump stops are removed, what I need to do is remove the cab/box/engine, notch the frame at the rear axle, paint the frame, install the drop spindles I have for it, clean and paint the engine bay red like the rest of the truck, put the EGT gauge probe where it should be, fix the upper starter mount bolt, repair any floor boards that need it as I think the windshield is leaking as everything on the passenger side is wet, something is leaking, maybe more than one thing, make the rear windows function properly, paint the interior, do a bunch of other small stuff including firewall sound proofing and some dash wiring, and then put it all back together, it will be a nice truck then, it looks nice on the outside already as I had at least 4 strangers make positive comments today about it.

[wayno]

I am planning on doing some stuff to this truck in the near future, notching the rear frame as I bottom out a lot, I also will be installing drop spindles in the front, but I am not going to lower it but a couple inches, right now it has 2.5" drop blocks in the rear, I have a set of 3.5" blocks on the shelf, I also have a set of 510 Wagon leaf plates/shock mounts ready for this, I will do the same thing I did to the 520 except I am not going really low like I did to that truck.
I have a couple 520 dash tops and one 520 dash face that have been powder coated, I plan to install them, I also have a deluxe 411 instrument cluster I am wiring to work with the 720 wiring harness, most of that part has already been done to the 520 instrument cluster in it already except for the dash lights, well I figured out how to wire it properly in the 521 work truck so I will do it to this truck now.

The deluxe 411 instrument cluster


This is how I am going to wire the dash lights so they work the same way the 720 dash lights work as they have a dimmer switch.








Here is where I repaired my light circuit when one bulb shorted out below, that is the reason for the rubber tubing over the spring in the photos above.


While I was looking for parts to do all this I figured out that the Nissan 720 front marker light bulb housings will fit into the holes provided for the 411/520/521 dash lights in the instrument cluster, but I already made what I needed, here are 3 of the 720 marker light housings in the 411 instrument cluster, the only draw back is they do not lock into position, you can turn them too far and they come back out.


Also they are 2 wire plastic housings, they are isolated from ground which is what is needed, but the rubber seal is not thick enough to hold them in tight, but an o-ring fixes that issue.

Since I am removing the box to do the C-notch I will likely remove the cab to do the drop spindles, then I will also fix the upper starter mount bolt being stripped out issue, and while I am at it I will re-locate the EGT gauge probe to in front of the turbocharger where it is supposed to be, I will seal the windshield as I believe the seal is leaking and I will either make it so the rear windows will go up and down or I will seal them in position because they are leaking also the doors have drain holes in them to let the water out, these extensions do not have drain holes, I need to figure something out before the lower sections start rusting from the inside out.

There are a lot of things I didn't do right over the years, I want to fix them so I will never have to think about it again, but I enjoyed driving it the whole time, especially after installing the turbocharger.

[wayno]

So I did some stuff today on this truck, first I removed the windshield, cleaned up the painted metal the rubber connects to and did some smoothing out of the metal.


I used a new gasket even though the one in there was a new one, but this new one was dry.




I put the gasket on my brand new windshield I had cut at the same time I had 19 Datsun 320 windshields cut back nearly 8 years ago.


I forgot to take a photo of it installed while it was light outside.


Next I decided to get it ready for the rear frame notch, I don't want to cut the bed this time as there is some room between the frame and the bed floor, here is what I am starting with, you can see the gap.


Here are the pieces I will be using to stiffen up the top of the frame before I cut it for the notch.


I measured a few times and then made the cut, I didn't cut enough off so I had to trim it twice more to get it to fit correctly, better that then cutting too much off and having to fix it.


This is what it looks like on the inside(photo below), I will likely not be using the full length of what is in the photos, but I have to start somewhere, when I got it the way I want it I will weld a plate on the top all the way across after I taper the ends, that plate will stick out both sides an 1/8th inch, then after this piece is welded to the frame I will cut the notch and install it with an 1/8th inch sticking out both sides, then I will make plates that go from the top to the bottom that fit what I left hanging out, then I will drill several holes in the plate so I can weld everything together like it was spot welded together, I did this on my 520 but I will not be doing as large of a notch.




The bolt holding the bump stop plate was getting smashed on one side as the bump stops were removed.


Once I have both sides made and ready to be installed I will remove the box and hopefully be able to do both sides in one day, or I may do each side in a day so my back don't hurt so much, after the notches are done I will be installing a set of 4wd 720 leafs and the 3.5" drop blocks I have for it, just have to find the long U bolts, I already have the 510 wagon leaf mount/shock mount plates, I suppose I should clean them up and paint them.

I feel I did good today, it's supposed nice tomorrow also.

[wayno]

It rained all last night and when I got into the truck this morning the windshield was dry on the inside and the pass side carpet appeared to be dry also, I was used to using a squeegee on the inside if the windshield every time I got into the truck to drive it, I am pretty happy about this as i was worried it might have been something else soaking the carpet.
I was also worried that the new windshield was slightly smaller than the original as it didn't really fit the hole as nice as the original did, I actually had to put rubber tubing into the upper corners between the windshield and the gasket to force the gasket higher which worked very well, I then squirted some silicone in the corners to fill the void underneath, it appears that it doesn't leak right now, the upper part was not my worry, and the windshield settled at the base in the seal/gasket so rubber seal and glass appear to be not leaking also.
It is supposed to rain hard this weekend, if it stays dry I will call it good, next I think I will look at the rear kingcab windows, I need to stop them from leaking now or either figure out a better window seal, or silicone them solid, right now they have 720 squeegees in them, but they are not keeping the rain water out.
First I will try a door seal on the inside to force the glass tighter against the channel seal on the outside top and sides and then make it up as I go after that, that section was put in like I just closed the door on both sides, I had thought about door seals in from the start, but it made no wind noise so I forgot about doing that, I need to stop the rain water from getting in.