JackSun

The good news is I have found a 510/521 transmission for sale thanks to a friend whom sent me the link of one for sale. The guy is getting rid of it for a reasonable price, took a look and the extension housing is intact. My next option was going to be what King Rat recommended. Z trannys as that's about the only thing that can actually be found physically where I live, to which without dissecting or seeing it run in a vehicle I have no idea what condition the gears inside are in. W/ this one I'll have the housing covered and I know I have good gears on the one I have already, on the replacement, some are slightly rusted, of the ones that can be salvaged I'll just keep the duplicates for spare parts. Seems like a sure plan. This was a rare lucky find indeed. The guy whom found it also saved my bacon on my Z car, or I should specify, saved the dealership's bacon on that one, I just waited for it to work before snagging it off the B lot and for employee discounted pricing. He was the only guy in an entire GM car dealership that could solve the problem w/ my '83 ZX. - It took what seemed like an army of GM certified technicians to bumble and tumble around w/ the 280ZX for a few months (September - November 2010). The dealership was duped into the deal and found themselves stuck w/ it unless they could make it run. Load and behold the guy whom just located my transmission also located the needed replacement part (an ECM unit) and made the Z run, the others just cried and whined about never making run. He's a life saver. The first problem is was an obvious one (An army of GM technicians + Datsun 280ZX = Something that sounds like an intro to a bad joke)

I should say by "abundance" - actually the largest inventory you'll find in the state (which is only an handful) is old Datsun Z parts, so for many other obscure/rare models found regionally, I'm SOL or up the creek without a paddle if I expect to find these parts locally. :rofl:

Lots of good info here. Thank you I've been thinking about the modification alternatives over the past few days. This gives me a better idea of what to look for. Biggest challenge so far, and this is to be expected is just simply finding the right stuff to work w/. Datsuns are so few and far between in the this part of the country, thus so are parts. Without shipping a transmission from elsewhere, options seem limited. The most abundant in Colorado are old Z parts. I located a '72 521 in the middle of nowhere which could be a suitable parts donor, once in a blue moon a mini truck related deal comes up for sale in Denver. It's tempting to go after a cheap donor, since nobody else wants them, just so I'd solve the tranny issue (providing it's trans is not compromised at the extension housing) and have an abundance of parts for other unforeseen but potential problems. Minus the situation of additional truck carcass outside taking up space. I want to walk into some guy's garage and buy a stand alone transmission that will work w/ some mod work but even those alone are rare here. Also rare, people here who have much knowledge on Datsun related stuff. Unlike Cali, just not much Datsun help period. I have one buddy whom works at the GM dealership I used to work at, whom back in the day worked w/ them, he sent me entire online manuals. I'm truly out in no man's land on this one without this forum. It's a crash course fun and interesting learning experiment, playing around w/ the 521 but also a headache where I live, guess this is what happens trying something different, this is a truly a one Datsun town. I'll keep at it and get this solved sooner or later.

The frayed part is the aluminum housing. The seal is gone, it's like it was broken off. It's very strange.

Thanks for the help so far. A friend found an online manual. Looks like a F4W63. It looks like what I'm really after is the extension housing, lots of seals out there but nothing for the housing part.

Hello everyone, I'm new here so you'll see me coming here more and more often. I've been enjoying the Datsun pics and info on this great forum. I've got a 1971 521 and when I got it a few months ago (April) it was slightly leaky, when I brought it home, and it was an altitude difference, it bled out. When it ran, the exhaust smoked plenty, between the mess underneath and inside w/ oil, grease, mud and grime and the smoking which told me it needed a new head gasket, I decided to pull everything out and clean it all up and reassemble w/ new gaskets and seals. I found the rear end of the transmission where the shaft output was frayed and warped. It was some strange damage that I can't seem to find anything online about such a problem for comparison. I took it to a buddy who's a transmission expert at the auto dealership I used to work at and he has not seen damage like it. The big question was of course whether it was critical or not. The coconscious was yes but who knows how long the truck got by like this, it still seemed to retain lots of oil in the gearbox area when I drained it. Over the past few months I've searched for replacement end/output area housing for the transmission. It's broken and frayed where I think a collar would have held a seal. I've no considered finding a whole other tranny but all searches prove fruitless. I suspect now that maybe this transmission is similar to the ones in the later 620 but I don't know for sure, as diagrams, pictures and info on 4 speed manual transmissions in 1971 521s seems very limited, I very frankly don't even know what model of transmission I'd be looking for, if I were to get another. I've talked about the possibility of getting a machine shop to McGyver something up so dirt does not get up in there. Maybe it's not as bad as I think it is as the truck ran before without but something obviously tells me a gapping hole around the shaft in the back of the transmission won't work for long. I really want to avoid replacing it to begin w/, gears and all check out fine. As tempting as it is to hotrod this and drop a non stock engine and tranny in it would defeat the original purpose of this truck as a practical little economy fix'r upper get around town working truck. Plus I don't really have the equipment or know how to do all the cutting or non stock custom modifications. :geek: Long time Datsun Z owner, just now getting into the trucks and learning the ropes. I'd like to post photos of the kind of damage I'm trying to describe but I've yet to discover how to post photos here on this forum. I looked at the how to instructions, posted here but it seems that it might only work if I had a photobucket or some kind of pic sharing site. I just wanted to keep it simple and attach images of the truck from my computer. Anybody w/ any insight or advice into this crazy transmission mystery would be much appreciated. :confused: Thank You :thumbup:

Beautiful blue, I got ahold of a red 1971 521 last April. It's in rougher shape but overall not too bad, I've hit a few brick walls at the moment trying to work my way around them mechanically but I'm loving that blue.