ggzilla

That photo is labeled incorrectly. The dashed line is not at 11:25 From the Datsun factory service manual This blue line, and the spindle shaft, are both at 11:25. To double-check this, turn the crank to 0 (TDC) , then remove the distributor cap and see if the rotor is pointing to the #1 spark plug wire. If not, turn the crank a full turn to TDC again Then remove the distributor and see if the spindle is correct

That reminds me, Ratsun does not allow new member to upload a photo, until you have 18 posts or something like that

Take a pic with your phone, then come back here and tap Reply. Then a link will appear "choose files" (or "choose photos", depending on what kind phone you have). That will show you all the photos you can choose the one you want to include in the reply

This is the deal. GL-4 is what Datsun recommends for the manual transmission

Yes, if the light is burned out it won't charge Key ON, engine OFF: charge/battery light must be on. If it doesn't light up, that a problem right there Once the engine starts running the light should go out Did the problem start when he removed that battery cable from the running engine?

I've had two cars with blocked exhaust, they idled OK but had low power * 1974 Lincoln with 460 engine, drove OK but wouldn't go over 45 mph. The exhaust pipe tip was smashed in half from going over a steep curb * 1979 Pontiac 305 V8, hardly ran at all but I did drive it 10 miles to the shop. Didn't need to rev it up to get it going, but it was dog slow and felt like it was missing. When I disconnected the exhaust from the manifolds it ran perfect. Turned out the heat riser flap in the exhaust manifold had broken loose and so blocking the exhaust. Relatively easy fix

I had one of those, a brown 1978 Civic with 5-speed. It was a zippy little car that got fantastic fuel economy, but it was a tinny buzz box, inferior in most ways to Datsuns of the times. Now the 1978 Accord, that was 10x the car ...

GL-4 is for transmissions with brass syncros, which is most Datsun/Nissan gearboxes GL-5 is for differentials If the container says GL-5 AND GL-4 then it is supposedly "yellow metal" safe and won't corrode brass. However, Mystik JT-7 is "sulfur-phosphorus extreme pressure (EP) gear lubricant" and is not considered yellow metal safe On the other hand, Lucas Oil Gear Oil SAE 85W-140 doesn't say GL-4, but Lucas says "Our specialty formulation is yellow metal safe" ($16/quart at NAPA)

aah If it still turns smoothly in each gear ... drain the gear lube out, turn it upside down to drain the water out of the shift extensions, put new gear lube in. Wire brush the input splines and lube that. Put it in and run it If it doesn't turn smooth ... get another one. Cheaper to put a good used 5-speed in that to rebuild one

Can't see the photo, but rust on the outside does not mean it needs a rebuild. If the input shaft rotates fine in every gear, then go ahead and install it ...

Does it only have a lack of power when climbing hills? He mentioned climbing hills, but also said the truck wouldn't even move from a stop until 4000 rpm

Nice work and those new rocker panels look great

So the tricky part here is you have to change the water pump, because the clutch is built into the pump And then find the right diameter fan blade for your truck, with the correct water pump pulley so it all lines up correctly with the crank & alternator pulleys Best bet is to buy a complete set off of another 1972-1973 620 or from a 521 (which uses the same parts). They use the 330mm diameter fan It is my understanding that all 620 with L18 & L16 came from the factory with a non-clutch water pump. The L20Bs had clutch fans, as did most 510s with L16s

Replace both fuel filters? These are the symptoms By "barely moves" you mean the power is down, but otherwise can take off and accelerate up to 4000 rpm on a flat road? And it is only on hills where it "barely moves?

The most common problem with not cranking is the connections. usually the battery cables, so use a terminal brush on the battery terminals and inside the cables. Get it to shiny clean metal. I usually use a flat screwdriver blade instead of a brush Then coat bother with terminal spray or a thin coating of grease. Repeat once a year If the cables are green with corrosion they might need to be replaced