620 castor. Early vs late. (plus other ramblings)

[Valvebounce]

I don't visit this site very often.

But I thought I'd share some observations I've made.

 

So I've got what was, a one owner 620. Bought brand new by a guy who lived in a part of New Zealand, VERY a very dry climate. A year and a half or so, the poor old girl was in a frontal impact. (The owner is in his 80's)

It changed hands a few times. And then I had the chance to buy it as a rolling shell for the right price. (The guy I bought it from kept the J15 for a woolsly 15/50)

I already had a '78 620, which I bought off a mate up who's brother's business' landlord is the old boy who owned this truck.

To cut my essay a bit shorter, (I've had a few beers tonight) I found that this crashed truck was so rust free, that It was worth saving.

So I began the hunt to find a donor cab to do a front cut. (The guy who removed the engine had cut the whole front to get the engine out)

Another friend was seling a '73 that't he'd begun fixing up, but it was completely stripped out. Some of his repairs were a bit rough. So I had no compuction about choping it up.

So I cut the inner guards out of the firewall, and then unpicked the spotwelds to render the donor front able to be reused.

Then I dragged the unrustiest 620 shell you ever saw into the shed to begin unpickeing the inner guards off the firwall.

 

Okay, now the whole point why I started this thread.

Whilest working on these two trucks I noticed that the '78 has the mounting for the upper wishbone canted to ceate negative Castor. And the '73 has nuetral castor on the upper wishbone mount, but it has adjustable castor rods unlike the later model truck.

I had though, shit, I could switch to a longer bolt on the rearmost mount, and add a spacer to crank up the castor. But seeing that the early ones had adjustable rods, it's nothing to throw my rods in the lathe, and screw some more thread on to increase adjusablitity.

On datsun B110's, and B210's, where the castor rod bush is fabbed up from thin ass metal, too much castor pull can cause the welds to crack on the castor rod bush pockets.

 

Perhaps all this is old news, and old hat to the 620 fiends. But I thought it was worth sharing/maybe got some discussion goin?

[datzenmike]

Our '78s and up 620s had disc brakes up front and the suspension is very different than the earlier king pin ones. Castor (and camber) is adjusted by adding or removing shims on the two bolts between the upper link spindle and frame. The earlier king pin trucks are the same.

 

Camber is adjusted by adding/subtracting the same number of shims on the two bolts

Caster is adjusted by adding or subtracting shims on only one bolt

[]2eDeYe]

Or in my case, slam it down, remove all the shims and spacers to get as much camber back as possible, then deal with it. :lol:

[Valvebounce]

My 78 also has the ball joint stub axles, but it's still a drum front brake.

The 73 has provision to adjust the castor rods. (nuts both sides on the castor rod pocket/bush)

 

I'm quite looking forward to having the new front sewn onto this truck. I mentioned it on here once before, but it's so rust free that all the fender bolts undid witout breaking off. Even the one right down at the bottom behind the front wheel.

 

Since I have a lathe at my disposal, It's nothing to make up shims of whatever thickness I require. I'll probably make the castor rods adjustable too. (Just cos a I can)

However, thinking about that today, the amount the lower arm can be cranked forward would be limited by the torsion bar pocket. Probably why the top mount has so much twist on it on the later ones.

[datzenmike]

 

The 73 has provision to adjust the castor rods. (nuts both sides on the castor rod pocket/bush)

 

 

Maybe a picture of this. Doesn't sound much like ours.

[Valvebounce]

I'll try, but I'm not much of a photographer. And whoever it was I used to host pictures with wants money. So I don't have a hosting site anymore either. (And I'm a complete cabbage at computing too)

[Valvebounce]

I took some pics today with my work phone.

Does someone want to offer their email addy for me to send to some pictures to to post up for me?

I'm already 6 beers deep tonight, so I cbf trying to do battle with computers/the internet tonight.

[]2eDeYe]

I took some pics today with my work phone.

Does someone want to offer their email addy for me to send to some pictures to to post up for me?

I'm already 6 beers deep tonight, so I cbf trying to do battle with computers/the internet tonight.

 

PM sent

[cr83]

use photobucket man

[]2eDeYe]

use photobucket man

 

That's what I use :)

 

 

 

 

 

 

Just realized there are more pics 

 

 

 

Motor mounts are strange to me...

[datzenmike]

J series?

[Charlie69]

I know that 620 in Mexico had J motors in them.  And Mike is correct that is a J motor mount.

[]2eDeYe]

Here you can see the back of the '73 castor rod pocket. 

See how there is an adjustor nut here, and extra thread not found on the '78 model. This enables the lower arm to be pulled forward to increase castor.

 

 

 

Here's a picture of the truck with zero structural rust (Bit of surface rust creeping in fro being parked outside with the panels removed) With the front inner fenders unpicked in preparation for the new front. 

(really just threw this one in for interests sake)

 

 

[]2eDeYe]

Here you can see a straight down birds eye view of the '78 620 upper wish bone mount. You can see that the mounting is cantered, or twisted if you will to create much more castor than if it was straight. (Center line of the pivots parallel to the axis of the driveline)

 

 

 

[datzenmike]

Strangely the 'down under' 720 had L series engines in them.

[Valvebounce]

Thanks dude!

So you can see how the later ones had more castor dialed into the top arm mounts.

Also, ALL the NZDM 620's were J15 powered. (actually some of the very early once might have even been E1 powered) The picture with the shonky mounts had actually been been altered to take an L16.

Our radiator support panels were a bit different to the L/SD powered cars. Our radiator supports are kinda straight. Whereas the L series/SD diesel powered trucks had the radiator recessed forward into said to panel.

[datzenmike]

 

Our rad supports were recessed from '75 on for the larger L20B rads.

 

[Valvebounce]

Ah I see. Thanks for the info.

 

Anyway the pictures show how the castor was done differently on early vs late.

The Rad support on the donor front has been (gas!) cut out to take the bigger radiator. I have a pretty big copper radiator out of a VK Holden commodore (POS Aussie car) that had been running an LD28. So I'm going to tidy up where it's been butchered. And probably fold up some new sides so it doesn't look hacked, and to keep the air flowing through the radiator in stead of around it.

Looking at my truck with the front gone, I think I'm going to mount the sr20 and box while it's in this state too. There is so much room to work around everything when it's like this.

I also just noticed that the wheel alignment looks to be towing out to buggery. I'd better check that none of the arms are bent or anything. Shouldn't be too hard to find replacements. Datsun prices here have started going silly of late. BUt the good ol 620 seems to not quite be there yet. Parts are still crazy cheap.