hucklefish

Maybe I'll peen it on both ends. I'm more worried by the whole starter coming loose last week. Could that happen because of the pilot bushing being knocked out and then the pinion gear becoming crooked enough from repeated starting with pilot bushing, which then maybe caused enough vibration to loosen the bolts in spite of lock washers? Looks like the only option for a new starter is from Germany or England, running $200-250 with shipping, so I want to make sure I'm installing it right.

Would you guys have any ideas about why my starter pilot bushing keeps coming out? I've got replacement bushings, and I've got a replacement nosecone, but I'm afraid if I just keep replacing them I'll burn through them pretty quick. Is the bushing supposed to be peened or chiseled to lock it in place or something? Also, this time it's not just the pilot bushing coming out, and I don't know what happened first. The top bolt that holds the starter on fell out completely and the bottom bolt loosened to the point that the starter was hanging at an angle, and the starter pinion gear shaft is a lot more wobbly than I remember it being last time I had the starter out. So, I guess I should also ask if you guys have any idea why the starter bolts would loosen.

@pidge, I've made two custom parts orders from sendcutsend.com, and I wrote up my design process and the experience with sendcutsend in two posts, which I'll link to at the bottom of this one. I also designed a little throttle return plate to go on your throttle lever like I described above, and I was going to include it in one of my orders and just mail it to you, but I forgot. I think I can probably attach the dxf file to this post as an attachment, and you could upload it to sendcutsend and order it yourself if you're interested. Or you could probably make one yourself with a hacksaw and drill and save some money, so I'll also attach a PDF that you could print out and use as a template - notes on that below the screenshot. It's designed based on my throttle lever, so I don't know for sure that it would fit your throttle lever, but I think yours is the same as mine except rotated about 90° ccw. Here's a screenshot, with some notes to explain: You could probably make the bend in a vise with a drill bit and some kind of V-block. The PDF has dimensions, and I highlighted the only ones I think are critical - the rest are just suggestions. I'm not sure how you'd make the pin by hand - maybe in a shop press if you could drill a hole the right size in a piece of fairly hard steel and put a tiny button of weld on another piece of steel to make a pair of punch press dies. Or the male die could also be a bit sawn off the end of a grade 8 bolt and epoxied to the top block. My post on making a carburetor throttle cable bracket using sendcutsend: My post on making an alternator bracket using sendcutsend: SCS-throttle-lever-return-01.dxf

In the morning, Ratsun! I just want to share a pretty useful resource I found recently: https://sendcutsend.com/ I've made a throttle cable support bracket for the Nikki carburetor on my 520 using this service, and I've got the pieces for an alternator bottom mounting bracket. Full write-up on the alternator mount following, and for pictures of the throttle cable bracket from 3d printed prototype to metal pieces on the truck, see my post linked at the bottom of this one. First, the important little details you might be asking by the end of the post. I have 26 years experience as a drafter, mostly in AutoDesk products, and now that I've escaped full-time desk-sitting forever and no longer have access to the "real thing" I use ProgeCAD, which costs about $200 for a license, looks and feels almost identical to the latest version of plain vanilla AutoCAD, and has an FEA module and some other interesting looking tools available for additional licensing fees. My 3d printer is an unmodified Ender 3 Pro, I use Cura 4.10.0 for slicer (Windows 7, can't upgrade), and I'm printing lately using Polymaker PLA+. Sendcutsend has a minimum order of $29, which includes shipping, and these two projects cost me $29 (alternator bracket) and $30.71 (throttle cable bracket). One thing to note is that Sendcutsend provides an estimated shipping date, and for some reason I thought that was an ETA, but it's actually when they expect to ship the order out. Shipping took less than a week if I remember right. I could have paid extra for express shipping, but there's no speeding up the manufacturing - it's first come first serve. My 520 came to me with no top alternator bracket and the bottom of the alternator mounted in a weird looking double bent plate pair bolted to the motor mount. The alternator hda a pretty noticeable front to rear wobble which I thought was probably because it was only held by those 2 bolts pinching two 3/16" thick plates against one of the plates of the motor mount. It also came with what appeared to be a lawnmower belt running the alternator and water pump, and when that disappeared somewhere between here and Home Depot, I replaced it with the proper belt, and the wobble went away. But before that happened, I had already designed a more correct bottom alternator mount and sent off the order to sendcutsend. To get the dimensions of the mounting holes, I held this piece of cardboard against the straight edge running along the side of the engine block right below the original mounting holes, and tapped all around them with the round head of a ball peen hammer until the holes and their bosses were well marked on the cardboard, as well as a small rectangular boss above and slightly to the rear of the bolt holes.I think the 2-7/8 note is the distance between the two lower holes, as measured by holding a steel ruler against them. To get the dimensions to and orientation of the desired position of the alternator bottom mounting hole, I found this piece of cardboard with its handy 90° crease already made, and held it against the rear face of the existing alternator bracket and the tab at approximately 90° and positioned over the lower forward bolt hole (the one circled in the previous picture. I measured the thickness of the existing bracket and the width of the mounting boss on the bottom of the alternator and noted them on the cardboard. Using these dimensions I drafted a 3d model and printed it out to test fit it on the truck. For clarity, here's sort of how the cardboard reference pieces sit in relation to the bracket, except that the one with the bend in it would actually go behind the rear fin: I needed slightly more clearance between the alternator bottom and the outside corners of the horizontal web between the two fins, and I also decided I wanted a little more lateral stiffness between the fins, and why not extend the horizontal web to the rear corner and lengthen the radius on top of the fins? I knew these changes wouldn't create any new interference, so for the next 3d print I also converted the model to a set of 3/16" thick plates that fit together with tabs and slots. Assembled: ... and unassembled: Before uploading the dxf files to sendcutsend I made one more change that wouldn't really be visible, but was important - for tabs and slots they recommended adding a 0.01" tolerance between the tabs and slots. In hindsight 0.005" probably would have worked, but the pieces fit together easily and I don't think they'll be difficult to hold together for welding. Here's the 3d model and the flat version side by side: I specified 3/16" hot rolled steel with no finishing. Unboxing: and pieces assembled I've had the pieces here for a couple weeks now and other things are more pressing, but in the next day or two I may get around to welding it together, painting and installing it. When I do, I'll update this post with more pictures. Once I've verified my design really works I'll upload the dxf files here in case anyone else wants to try this. The throttle cable mounting bracket was slightly different, as it needed several bends for stiffness and to accommodate hardware and pieces on different planes. Getting the initial dimensions was a lot more complicated, and I went through several 3d printed prototypes before I had one that fit and cleared everything it needed to. To get the dimensions of each flange correct, I used sendcutsend's very detailed and helpful articles on designing bends into a metal part, along with their bend calculator. Dashed lines in the dxf files automatically prompt sendcutsend's ordering system to ask for degrees and direction of bend for each line. The bend you're entering values for is highlighted in the 2d view, and the resulting bend is immediately shown in the 3d view as you enter the values. Here's the prototype 3d model and the flattened version: I ordered the parts in 0.06 thick 304 stainless steel. For some reason they sent me two of the main bracket, and I can't find any errors in either one. Only one sticker this time though... For the rest of the throttle cable mounting bracket, see this post in my other thread:

Is the proper gasket cardboard? I made one from a Felpro cardboard that's supposed to be good for carburetors. It wasn't bad, I just thought it could be better sealed. I'm pretty sure the black tip isn't rubber - this carburetor is less than a year old (from Thailand I think previous owner said), and that tip is at least as hard as the rest of the needle. I'm pretty sure I could scratch some of it off if I tried, and it feels and looks exactly the same as the coating/finish on a sheetrock screw, which is black oxide, and which I understand can be applied to brass for corrosion and wear resistance. Vacuum signal makes sense - whatever is on top of it doesn't just fall out, so it must be a spring-loaded valve or whatever? Or just an open passage? Looking at the carpartsmanual diagram, it looks like the upper end of it must be right next to the big hole near the center top. Here's a carburetor on eBay that looks exactly like mine: https://www.ebay.com/itm/263743348020?chn=ps I'm thinking that screw must come up right below where the red circle in this picture: The secondary is the barrel on the right. Could that large hole next to the red circle be the power valve? Gas was coming out of that hole when the float was stuck down. So I'm guessing gas is delivered to that hole (power valve hole) via an always-open port in the float bowl, and higher than normal vacuum delivered through the hollow screw opens a spring-loaded valve in the bottom of power valve hole, which allows it to be sucked through a port into the venturi in the secondary barrel. I also see that carpartsmanual shows a lock washer that I'm missing on top of the hollow screw. That would probably be better than blue Loctite, so if I ever take this carburetor apart again I'll try to remember to make that switch.

And here's what I did to get the carburetor running again (though I haven't test driven it yet): First, I removed the carburetor and adjusted the metal tabs on the float until it would sit approximately level with the carb upside down and not go all the way to the bottom of the bowl with the carb sitting upright. I don't have any pictures of that process. Here's the float bowl marked up with some colored arrows to explain what's what: The black arrow is pointing at a tiny brass spacer (carpartsmanual calls it a collar) about 1/8" long, which I managed to avoid dropping on the side of the freeway, but which I forgot to put back in the last time I reassembled the bowl glass on the side of the freeway, and it rode all the way home in the little depression in the top of the radiator cap. Since then I've twice dropped it through the engine compartment into the gravel of my parking spot, but managed to find it so far. The red arrow is the bottom end of the needle valve. All you can see of it here is a little spring-loaded rod that projects from the bottom of the brass barrel. It rests on the float height adjustment tab (yellow arrow). I bent this tab until the float sat approximately level with the carburetor sitting upside down. The green circle in the lower left is around what I think is a port that allows gas to flow into the accelerator pump cylinder. It bumps out about 1/8" from the wall of the bowl, and the float gets stuck on it if it goes all the way to the bottom. I adjusted the float stop tab (blue arrow) until it stopped the float from reaching that bump. After these basic adjustments, I reinstalled the carburetor and turned on the key to run the fuel pump, and got no fuel into the bowl. I took the glass plate off the front and tried prying the float height adjustment tab down with a screwdriver between it and the bottom of the valve assembly (the brass part just above the end of the red arrow). I couldn't seem to get enough movement, so I came inside and looked for more info, Somewhere I found a forum post mentioning a gasket between the fuel inlet and the needle valve assembly that could be doubled to increase clearance between the float tab and the needle valve. I don't remember if it was talking about a J13/Nikki, or some other Datsun model altogether. But my needle valve assembly had an aluminum gasket on top and bottom that looked identical. The one on top had been kind of crushed by the bottom of the fuel inlet fitting. I pried it off carefully with a sharp knife and put it on the bottom, reassembled everything, and she works perfectly and doesn't leak gas anywhere (yet!). Here's a closeup of the float adjustment tabs: and here's a closeup of the gaskets under the needle valve assembly - hard to see, but if you look at the right side you can see a line between the two gaskets (aluminum washers between the pot metal of the carburetor top and the brass needle valve assembly, the six-sided brass part):

Here are a few pictures of the new throttle cable bracket and its prototyping process. One of the first 3d printed prototypes, missing a bolt hole tab on the left that broke off when trying to force it over the carburetor studs. The piece laying in front was screwed to the right end with the throttle cable passing through the necked down hole between them. Final 3d printed prototype fitted in place and working okay with all clearances verified. I'm measuring the throttle cable lever here because I wanted to change the angle of the throttle cable, but it wouldn't make a difference to the rest of the design. Here's the 3d printed prototype a few hours later, after about half an hour of engine idling while I drained and flushed the cooling system. PLA+ isn't very heat-resistant, but I figured this would work long enough to verify that I could start and idle the engine and work the throttle linkages through their full range of motion with no interference. Here's the metal design, still in its vacuum packaging from sendcutsend: For more on how I used CAD, 3d printed prototypes, and sendcutsend, see my other post here on my alternator bottom bracket: Here's the main bracket in its original shape. They sent me 2 for some reason even though I only ordered one. Last minute I started thinking about where to attach the throttle return spring and decided to add the tall leg up to support the choke cable bracket above and maybe attach the spring somewhere between the two brackets. The extra little angle piece is in case I needed to reinforce the leg up. I would have riveted it to the near face, but I'm glad it wasn't necessary because it would have been right in the way of the throttle cable clamp (the little piece on the lower left corner of the vacuum pack card in the previous picture - it fits into the slot next to the bottom of the leg up). I drilled and tapped holes for 10-32 screws in the top of the leg up and on the face of the tab down below the slot. Sendcutsend's bending options are limited to air gap bends 90° or less, so I had them make the bends I needed on each end of the cable clamp and then I used an assortment of needlenose vise grips and lineman's pliers to bend it into a U shape around a 5/32" drill bit. I don't have a picture of that, but you can kind of see it in the following pictures of the bracket installed on the carburetor. brake cylinder gets in the way here, but you can see I had to twist and bend that leg up a little bit to get it aligned with the hole that was already there in the choke cable bracket. I also gave up on a creative new attachment for the return spring, because it's just too long to go anywhere besides on the choke cable bracket. Also, that's the original choke cable housing I'm holding, where it belongs (aftermarket one coming in from the lower left will have to be good enough until I can manage to drill the old cable out of the original knob extension and replace it): looking at it from the back, you can barely see the jam nut I put on the back of the screw through the cable clamp: And in this more straight-on side view you might be able to see that I slightly straightened the little arm on the other throttle lever on the back so that the return spring has a straighter pull from the choke cable bracket and not get so wrapped around the ball-end linkage. Still far from perfect, but getting better.

In putting everything back together I found this screw in the middle of the bottom loose again. As far as I can tell it's just one of the screws that hold the top and bottom half together, and even though it has a hole clear through it, doesn't seem to meter fuel in any way. So I put it back in with a few drops of blue loctite about the middle of the threaded portion. The black greasy looking stuff is non-hardening gas-safe Permatex.

Nah, I'm pretty sure it's a factory finish of some kind (black oxide maybe?):

The pump is under the driver side door on the frame rail. It's a low pressure pump that replaced the higher pressure pump PO had on there. I don't have the original mechanical fuel pump, but this electric one is closer to the tank and lower than the original position on the block. The needle is all brass with a seating surface that looks sort of blackened by some kind of coating (looks like factory applied, not some kind of deposit). I'll look at the top of the tank, but I've had it nearly empty before (with the original electric fuel pump) with no problems. The only variable from that time to this is the new fuel pump and some tinkering with the linkages on the carburetor (throttle and choke cable mounting, throttle return spring, and test-fitting a 3d printed prototype of a choke cable mounting bracket). I'm going out right now to adjust the float and remount the carburetor with the new throttle cable bracket, and I'll upload some pictures of everything when I get done.

I've got a new puzzle. Going about 65 on the freeway, suddenly felt just like I was running out of gas. I was only three miles from an exit with a station, so I coasted as far as I could, eventually had to face reality and pulled over, tried starting it again a couple times, and no luck. Called my wife to bring me a can of gas, poured in the 2-3 gallons she brought, dripped some into the carburetor, and tried starting. Start, but died as soon as it burned off the gas I dripped in. I took a closer look at the carburetor and found the float resting on the bottom of the bowl with a few drops of gasoline, and the see-through fuel filter on the fender had no fuel flowing into it even though I could hear the fuel pump whining (electric, 2-3 psi, mounted on the frame rail below the driver's door). I called a friend and he suggested that if the line from the tank comes off the top of the tank (it does), and if it was dry, the fuel pump might be starved and too weak to prime itself from a nearly empty tank, so I might try filling the tank the rest of the way. Wife and I went and bought another gas can and a funnel, filled both cans up, and went back to the truck. The funnel was so I could take the stupid leak-preventer gimmick off the gas can spout and pour straight from the can into the funnel instead of having to hold the thing open and get gas all over my hands every time I shifted slightly and it quit working. I bungeed the funnel to the bed rail and started pouring gas in. Not worried about overflowing the fill pipe with the first can, because it's a 10.8 gallon tank and I "knew" I only had a couple gallons in it so far. About 3.5 gallons into the first can, the fill pipe overflowed. So it can't have been actually out of gas, right? So I put the can down, watched the gas slowly drain away from under the gas cap lid, replaced the gas cap, put the can away. I turned the key to on, got down beside the driver's door and verified I could hear the fuel pump running, and stepped forward to see if there's fuel in the filter and bowl. First thing I see is the fuel filter full and flowing. Next thing I see is the float still resting on the bottom of the bowl and gas fountaining out of the top of the carburetor. I rushed back and turn the key off, then cam back to look at the carb again. Standing gas in both barrels, gradually draining down into the manifold. So I took the glass plate off the front of the float, carefully caught the tiny brass collar on the end of the float axle, teased out the float while holding the needle valve up out of the way with a flathead screwdriver, then caught the needle valve. I wiped a trace of rusty gas out of the bottom of the bowl but saw no other problem. Stuck the float back in and found that it seemed to kind of catch on a little bump in the bottom that might be the port into the accelerator pump cylinder. I thought maybe the tiny brass collar was supposed to go behind the float to hold it out away from the back wall of the bowl, so I tried assembling it that way, but it definitely goes in front, which I verified by pulling up carpartsmanual on my phone. I reasoned that maybe the float only catches on that bump in the rare event that the bowl runs dry, so I reassembled everything and tried the fuel pump again. I can't remember now whether I got the fuel fountain again or the dry bowl next. I only remember that I took it apart and reassembled it 3 or 4 times after that, and one of those times I took the fuel strainer and inlet apart thinking it would be more effective to drop the needle valve in from above (doesn't work), and another time I bent the metal tabs slightly on the float to try to adjust for less pressure on the needle valve, or more. I probably tried both. At some point it started raining, and I reassembled everything and tried one more time, then called a tow truck. I haven't looked at it again since getting it home. I got a new radiator for my other work truck and have been busy putting that in and driving the family car for work. This evening and tomorrow I plan to disassemble the carb at least partway and clean and reassemble it, checking for obstructions and adjusting the float properly according to directions I assume I'll find either in the service manual or somewhere online. I'm guessing I can fix the float sticking to the bottom by adjusting it properly and not running it completely out of gas again. But I'm still puzzled by the initial "running out of gas" with half a tank. It wasn't nearly as hot as other recent days, so I wouldn't think it was vapor lock. The fuel filter is brand new and there's no sediment in it. The fuel pump was running every time I turned the key on, and obviously has enough pressure to deliver gas to the bowl when it has gas to pump. The only explanation I've thought of is that this might have been the first time I've run the gas tank down to half full or less since I swapped the lower pressure pump for the one PO had installed, that was flooding the carburetor, and maybe the lower pressure fuel pump is too weak to maintain its prime once the fuel level drops that far, at least at freeway speed. If so, I'm thinking I need to switch back to the more powerful pump and add a pressure regulator and a return loop. Or don't drive on the freeway when it's below half a tank. Anybody have any other suggestions?

NOS brake adjusters from datsun-roadster-parts on eBay are twice the price of new ones from Thailand - are they that much better? And new parts made in Thailand in general - reliable, crap, or good enough for the price?

In the middle of trying to figure out my options for upgrading or rebuilding the brakes on my 520, I found this: http://www.bluehandsvideo.com/uploads/4/4/3/5/4435437/datsun_interchange_1966-78.pdf I think I understand how this manual works, but could somebody correct me if I've got this wrong? On page 18 (520 index), for '66-69 front brake assembly, it says 304. On page 40 under "304 FRONT BRAKE ASSY" I see parts numbers for RH and LH assemblies and the years and models these part numbers were used in ('66-69 520 and '69-72 521) From this I gather that I can use a front brake assembly for a 521 interchangeably with my original one, and I assume therefore that parts of that assembly are generally interchangeable as well, with some variations. The carpartsmanual diagrams show 3 part numbers for the '65-72 520/521 RH front brake assembly, so this seems to confirm that. Since carpartsmanual lists both a 3/4" and a 13/16" cylinder and the inerchange manual only lists 3/4", I assume I just have to know what part I have before I order. This wasn't a great example, because carpartsmanual combines the 520 and 521 brake parts. But scanning randomly, I find that "1126 HEATER CORE" was used in the '66-67 411 as well as the '66-72 520/521: Comparing carpartsmanual diagrams confirms they share the same part number, at least up until 9/68: AND So I should be able to swap a 411 heater core for my 520 heater core. Did I do that right? Next question, in the interchange manual, does anybody know what notes like these are referring to? Who has/provides "our #972" Third question - interchange means equivalent or identical parts, right? Not necessarily just parts that fit either model. Has anybody ever tried compiling a list of parts that can be swapped in a broader sense, as in they fit but may not be equivalent or identical? Thanks

Thanks again, both of you. For now I'll clean up the brakes and put everything back together, and maybe replace the wheel cylinder, maybe not. Then I'll start looking for an early 620 master cylinder, and later I'll think about upgrading the front brakes and probably keep the rear drums.Much earlier on this thread somebody said I shouldn't use this 520 as a work truck, and two of the reasons given were the drum brakes and the probably worn out king pins. Since I plan to go ahead and use it as a work truck and keeping fixing it up as I go, would either of you still advise sticking with the drum brakes all around? I'm a handyman, and I typically carry around probably 300-500 pounds of tools and mixed "just in case" materials and hardware. So far, in about 2 weeks of use, I've had no problems other than the brake bleeder screw popping out. Somebody in a different thread said "NOT SILVERMINE CRAP" and Beebani agreed, but that was a thread on a 620. Is there a better option than Silvermine for 520s? I've been through the first 4 pages of the Brake threads and haven't found anyone talking about upgrading a 520. EDIT: Found a positive review of Silvermine Motors products here, though it's for a 280Z:

What are my options for rebuilding and eventually upgrading my 520 brakes? My right rear bleeder somehow backed itself out while I was driving and I had to finish the drive with the hand brake. I put it back in against my better judgment and started bleeding, then messed everything up by forgetting to put the brake drum back on and pumping the brake pedal until the wheel cylinder popped its pistons out completely. Decided it's time to at least replace the wheel cylinder, and I have a new one in the parts bin that came with the truck. However, I've also drained the master cylinder several times, so I think I'm going to have to bench bleed it. Eventually I'd like to upgrade to disc brakes all around, and if understand right that will require a new master cylinder. So I'm considering replacing the wheel cylinder with the one I've got, and upgrading the master cylinder now. Is there a bolt-on master cylinder that will work with my 4-wheel drum brakes and work later with front disc and rear drum brakes, and still work later with 4-wheel disc brakes? I found this: https://www.silverminemotors.com/products/15-16-upgraded-master-cylinder-for-620-520-521-310 I've seen the name Wilwood a lot here too. They also sell this: https://www.silverminemotors.com/products/1964-1977-datsun-620-520-521-310-front-brake-upgrade-kit and https://www.silverminemotors.com/products/1964-1977-datsun-620-520-521-310-truck-rear-brake-upgrade-kit?variant=44444661350714 If I read the descriptions right, these require some modifications, but no swapping in parts from other trucks (machine hub down 1mm and get larger wheels for the front, modify e-brake cable and get long housing bolts for the rear). Are these kits good? Reputable? Anybody here used either of them? Are there better options out there? EDIT: I should add I'm not opposed to swapping in parts from other trucks if that's a more cost-effective option or better for future maintenance or parts availability, but I want to keep the 1000kg payload rating in the rear.