2Wheel-Lee's 1975 Datsun 620

[2wheel-lee]

Here's my build thread...I bought this 1975 Datsun 620 a few months ago on a whim. Having this as a project makes absolutely zero sense. I'm a widower with 4-year-old twin, so it's not something I can drive anywhere with the kids. Fortunately, it's not my daily driver. 

 

My first vehicle was a '76 620 that I bought wrecked when I was in high school. Though my ownership of that was short lived (I sold it back to the guy I bought it from after I rebuilt it), I was a mini-trucker for many years. 

 

As mentioned, I bought this 620 on a whim after seeing it on craigslist. I saw it on one day and went and bought it on the next. During my test-drive, I struggled with the idea of getting it - it drove worse than I remembered. Even at their best, 4-wheel drums suck. No power steering? Everything rattled....the rear window, the hood, the doors, and on and on. Some of it was fixed just by doing some door striker adjustments. 

 

Anyhow, though I posted many of these pics in my intro in the 620 forum, I'll add them here as well. This is what I started with. I have to say that it looks better in pics than it does in person. It was repainted at one point. I know some of you are thinking to just leave it as-is...but what fun is that?

 

Objectives:

1. Have fun building a 620 like I wanted to when I was younger.

2. Expose my kids to doing stuff. I want them to have memories of this build. 

3. Make it nice. I struggled with the idea of show worthy, but for practicality purposes, I'm just going to keep it practical. 

4. Improve the overall performance, while somewhat staying with a style common in the late 80s/early 90s. 

 

 

 

 

 

 

[2wheel-lee]

My first craigslist parts score. I just needed the guy's solid back window for $30 (to fix one rattle), and I left with all this stuff for $200. I don't need it all, but it never hurts to have spares, right? Yes, that's a 5-speed. 

 

[2wheel-lee]

OK, I wanted to really drop my 620, so I obviously needed 4x4 springs, right? While looking for something else on ebay, I saw some 720 4x4 springs. Well, as much as I'd like to have scoured around all the junkyards around Orange County, California, the reality is that there aren't many. And I haven't seen 720s in a long time, let alone 4x4s. OK, so I don't go often. It's also particularly hard taking 4 year old twins to a pull-your-part kind of place. Trust me on that one! Being a full-time dad, I'd otherwise have to find a babysitter....or risk them getting under/into/on top of everything. 

 

So the ebay deal started to seem better and better. For $130 shipped for both springs from Idaho, I think, to southern California, it was well worth not having to find them elsewhere. 

 

What are those pieces hanging off the bottom of the overloads?

 

I also need to find that thread that had the correct part numbers for the Energy bushings. 

 

 

 

 

 

3" lowering blocks. It's been probably at least 25 years since I bought a set of these. 

 

 

[2wheel-lee]

Got my wheels. For me, and most of the minitruckers from around So Cal, one of the ultimate wheels for the 620 is the Porsche (Fuchs) alloys...I've always loved these, but never had them. It wasn't easy, but I found two sets of 16x6s. These are the late model ones with date stamps of '88 for the black set and '89 for the silver set. 

 

 

 

[Lockleaf]

Yes, bottom flat leaf is an overload spring.

 

Don't forget to get some shims to adjust your pinion angle with the 3 inch drop.

 

Sweet truck.

[2wheel-lee]

This is actually how the truck has been in the garage for the past couple months while getting the hubs and axles redrilled for the 5-lug wheels. 

 

 

 

Most of the suspension was well protected by very thick layers of grease in various hardnesses. It took a lot of that Purple Power to get to this stage. 

Yes, I'm staying with the kingpins for now. Maybe some day I'll convert the front to ball joints. 

 

 

[2wheel-lee]

So long as I'm replacing the leaf springs and brake lines, and that the axles are out of the housing, it's probably the best time to clean up the rear end. Apparently, the pinion seal leak and one of the axle seals leaked, so I need to replace them, anyway. The housing will be painted with POR15, as I've been doing with some of the other parts. So far, I seem to like this stuff. It actually brushes on fairly well. 

 

[2wheel-lee]

To accommodate easier exhaust routing as part of a later plan, I decided to go with coilover front suspension using Beebani's mounts. They take a bit of finessing to make them fit to the truck. The bending isn't very consistent as one of them sat about a quarter inch higher than the other. I know, my cut wasn't very straight either. But it doesn't matter, I tried both brackets on both sides, and one of the brackets always sat higher.

 

I got a set of the shortest QA1 shocks available with 400 pound springs, mostly based on what many of you guys have had success with. However, because I plan to have the truck fairly low, I may up that to a stiffer springs later on. 

 

 

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I don't need the topout bumpers any more, so the bumper plates on the upper control arms were removed.

 

[2wheel-lee]

After mocking everything up, even the shortest coilovers don't allow the suspension to be dropped very far. I'm guessing that wasn't part of the bracket design. To be able to lower the truck more, I made these 1/4" spacers. These also were used to tie the brackets better to the frame. 

 

 

 

I was going to have a friend bring his mobile welding rig over to the house, but scheduling was a pain. I've always wanted an excuse to buy a MIG welder, so I got a Millermatic 211. After all, I'd spend less owning a MIG welder than paying someone else to do all the work I need done. Plus there's a bunch of other things I need to make around the house. I had an extra acetylene tank the LWS was kind enough to exchange for a C25 tank, so I only had to pay for the gas.  

 

Though I have never MIG welded before, I figured it couldn't be that hard. I have a bit of experience welding with TIG and with a torch. I did a couple practice passes on some scrap steel and then just went for it. I was having difficulties seeing what I was doing, but only after I was done did I see that the shade setting on the helmet was too high. Oh well, I'm happy how it came out for my first time, especially considering that this isn't the most comfortable position learn to MIG weld. 

 

[Charlie69]

Welcome.  Nice work.  Clean truck. 

[S30Jay]

Great truck, my favorite color on a 620 too!

 

I take any excuse I can to buy a new tool....

[Anderson521]

Super clean truck

[2wheel-lee]

So I installed the coils onto the shock. I thought they'd be a direct drop in, but they needed to be compressed to fit on the short shock (not shown above full extended, but still short). I bought this compressor at a silent auction at my work probably 12 years ago for about $45. It included multiple attachments for different spring sizes, this being the smallest. I probably couldn't have used many normal compressors, as the spring is very close to the shock body. I also like how the cups can pivot to accommodate the spring angles. I don't do much automobile work these days, and it's been sitting for the last 10 years, but I'm sure glad I didn't get rid of it!

 

 

I went with 400# springs based on what many of the users here have said that works for them. Those who are using 400s must really be cranking up the preload. I just did a quick mockup, and the static weight was just too much for the 400. I'm not exactly sure if the shock bottomed out (I know it's not the frame), but I know it would have been very close to where it would have. I'm thinking I may trying going up to 550# springs. 

 

Still, this is about the lowest it can go at bottom out. The control arm is about 3/8" from the frame bump stop pad, but without bump stops at the moment. I still need more low. :) 

I may be going to a ball joint setup with drop spindles sooner than I thought. 

 

[2wheel-lee]

I guess I should explain how those 5-lug wheels got on there. 

 

It's a shame that I won't be able to use those front hubs if I convert to ball joints. I'll need to get another set and have them machined. 

 

[an_orange_s2k]

I guess I should explain how those 5-lug wheels got on there. 

 

It's a shame that I won't be able to use those front hubs if I convert to ball joints. I'll need to get another set and have them machined. 

 

 nice! very interested to see how you did this, may consider it myself. the wheel selection for 5lug is so much better 

[Abe Froman]

Saw this thought of your truck,

 

[mklotz70]

I'd like to see a pic or two of the backside of both the front hubs and the rear axles.

 

If you convert to ball joints, you can use toyota hubs.....but they'll need a bit of machining.

[2wheel-lee]

I'd like to see a pic or two of the backside of both the front hubs and the rear axles.

 

If you convert to ball joints, you can use toyota hubs.....but they'll need a bit of machining.

 

Hello Mike, I'll get some pictures of the hubs/axles soon. Did you get my PM?

 

I've considered going with the Toyota 5-lug hub, and  I've seen your videos on that as well. 

Here are my concerns with that route:

- I was planning on using the Nissan 11.1" discs to match the rear 11.4" discs. I've only been able to find OE sized discs for those hubs. Are you aware of larger?

- The Wilwood calipers I have are for 11.1" discs (also work on 11"). The Toyota discs are 0.8". I could probably get pad shims, though.

- Though it would be easier with the Toyota hubs, they'd still need to be redrilled to 5x130 to fit these wheels. It looks like the face of the Toyota hubs sit further inward compared to the Nissan hubs. Have you measured that? 

[2wheel-lee]

picture fail...in the morning. 

[mklotz70]

Just sent the PM.

With your bolt pattern, I think I'd go with a wilwood hub instead of a toyota hub.  Your re-drilled hub is a drum hub....right?  

 

I don't know of any OE style rotors that are any larger.  The 13" being used on Bory's is a Wilwood.

The wilwood calipers we're using are for .81" rotors.....can you trade yours out with wilwood?  The calipers typically have a fairly wide range of diameters they'll work with and a set width.  The .81" wide rotors can be anywhere from 10.5" to 12.9"....something like that.

 

On my ball joint conversion, the Toy hubs mounting face is roughly a 1/4" more inboard than the HB hub. Might have been 1/8".  It was pretty close.

 

A wilwood hat over the hub would probably be just fine.  I haven't looked into that option much at all yet. 

[2wheel-lee]

Yes, the redrilled hub I have is the drum style, and I was going to use the Isuzu rotor. 

 

Wilwood hub? I haven't checked the specs on that. Are you thinking modify it as needed to make it fit on the hardbody spindle? Would still need to be redrilled for 5x130.

 

The wheels are 16x6 with a 36 mm back space. This limits my rotor diameter to about 11". Just looking at the Wilwood hat/rotor sizing, the only one with a hat that might work requires a 11.75" disc. That may work if the offset is at least 2". I'd need to test that. 

 

The Wilwood caliper is the 12-11132. I can't exchange it. 

http://www.wilwood.com/Calipers/CaliperList.aspx?subname=Forged%20Superlite%20Internal

 

I'm not as worried by the rotor thickness, as I can space the pads. 

 

By the way, I already have the QA1 coilovers. 

[mklotz70]

have you looked at this one?

http://www.wilwood.com/Rotors/RotorProd.aspx?itemno=160-11552-BK

[Bory]

2WL

I still have a set of wilwood 11.75 still in the box, if you want to fit test- BH's and I decided to go with 13's.

[2wheel-lee]

Here are the drum brake hubs machined for 5x130. After hubs were drilled, they 14x1.5 extended Porsche 944 studs were initially tack welded and then the fronts were brazed in place with silicone bronze to prevent them from coming loose. You could imagine what it would be like trying to remove a wheel only to have a stud spin! Silicone bronze was used because it has a lower temp required to braze it, reducing the chance for warpage. The holes that were plugged were done so with the original cut studs then brazed into place. 

 

You can see that the rear studs had to have a flat spot cut into them to more easily fit the hub. 

 

Unfortunately, what I didn't realized until partway through the process was how far the Wilwood caliper sticks out. Doing some rough calculations without having the parts with me, I figured that I would need to space the wheels out 3/4", so I called the shop to have them use longer studs so I could run spacers. I didn't really want to do that. This whole front end is made up of "must haves" that are making this all overly difficult! 

 

 

[2wheel-lee]

So I've been giving it a lot of thought over the weekend. I'm going to go with the ball joint setup, and here's my plan, along with a couple questions:

1. Going to go with Hardbody hubs redrilled to 5x130. I was considering the Toyota hubs, but the discs would be expensive (though probably equivalent to my plan) with too many unknown variables, but I'd have to have my hubs machined, and it sounds like Mklotz isn't available for a few months.

 

2. Hardbody drop spindles ($230, plus shipping from Stillen) 

 

3. I will likely go with Beebani's Pathfinder disc adapters and get 11" Powerstop crossdrilled/slotted rotors to match the rear. The hub face to the rotor is such that it should give me enough caliper clearance to the wheels so that I shouldn't need to run wheel spacers. 

 

4. Lower control arms..debating between Hardbody and 720 control arms. Is the length from the pivot to the ball joint the same? If they're the same length, is there an advantage of one over the other? Any advantage/disadvantage for the press-in or the bolt-on lower ball joint? I really like what Mklotz did for Bory's truck - that's exactly what I would have wanted to do, but I don't want to keep the truck on jack stands in the garage for several months waiting for that. So I have to make due with what is available. 

 

I'm not sure what I'll do for the strut bar. Either fab my own mount or I was thinking of making a heim joint mount. Any problems with that? I will also do something similar for the sway bar. 

 

5. Just the same, for upper control arms, I may have to go with Beebani's adjustable arms.