521 Radiator support swap out

[preventor5977]

Good day.  I'm new to this site and I'm sure if I was more patient, Id probably find the answer to this question.  I need to swap out the radiator support on my 71 521 and have noticed that the radiator support is welded to the inner fenders.  I am prepared to cut the support out and weld in the new one to the existing inner fenders.  Is this the best way to  do that or is there a simpler way?  Let me know ASAP because I need this truck back on the road soon.  Thanks.

[datzenmike]

Welcome to Ratsun!

 

 

Sure, trim the old one so that you will have several inches overlap to give it strength when welded up.

[Charlie69]

I you look at the support it is spot welded in.   Depending on how much you plan to replace determines if you can cut it out or if you will want to drill the spot welds and separate the pieces.

[Jester]

Preventor, there are a couple ways to go about it. Best, remove all the old core support and weld in the new one. Second, Laying one on top of the other is possible but only if your going to use a sheet metal seamer. Even a set of duck bill pliers is better than just laying one on top of the other. 

 

Good luck and welcome to Ratsun.

[DanielC]

Why are you swapping the radiator core support?  Did the truck run into something.  Yes, I have ran 521 trucks into other objects, but that was a long time ago.

 

If you are dealing with collision damage, check the fit of the doors.  This will give you a clue of how much damage you have.  fi the doors fit good, check fender fit.  Look for damage to the cowl, where the back top curved edge meets the cowl.  This area may be pushed back.   The inner fenders attach to the firewall.  The area where the inner fenders attach may be pushed back.  Pay attention to the distance between the door posts, on the cab, and the front surface of the headlight buckets.  If this distance is off, the fenders will not fit correctly. 

 

A hard collision may tweak the frame of the truck.  That may need to be checked.

 

The core support is made with the front cab mounts, and the inner fenders spot weld to that, but the back side of the headlight buckets have a "normal" weld between the bucket, and the inner fender.

 

 

On the other hand, if the core support is not extensively damaged, the lower grill opening rail is easy to remove, and replace.  once that is off, the front of the core support is basically a flat plane, with a few minor exceptions.

 

The thread below may have some pictures you find useful

http://community.ratsun.net/topic/49698-my-dragon-datsun-521/

[preventor5977]

The support is mangled at the corners where the headlight bevels go.  Its been a bumped a few too many times.  Also the support is damaged in the center from some incidents there as well.  The doors open and close good.  The old fenders were a little mangled as well.  The inner fenders are good though.  I measured them and read a plain along them as much s I could.  This is a new venture for me dealing with attached inner fenders.  Im used to American rigs where all the parts come apart and the support is just bolted to the front of the truck.  I think Ill just do the overlap weld and clean it up real nice so it's not visible.  Thanks for the help.  Like I said, Im a newbie to this but I'm really enjoying it.  The little truck is a head turner.  Not bad for a truck that was in a field dead for ten years.  

[Jester]

Post up some pictures of your truck. How to post pictures on Ratsun.

[Charlie69]

You would be better off doing a butt weld.  Hard to find a place that will overlap well.  Strongest is to drill the spot welds and separate the panels.  Did not take pictures of the ones I did takes time though and patience.  Be aware there was a change from early to late 521 radiator supports.  You need the later one sets the radiator closer to the grill.

[wayno]

I would just drill the spot welds with a spot weld drill bit myself, and it really doesn't matter what year the core comes from Charlie, you can just cut off the J block radiator mount sheet metal, and behind it are the holes for the L block radiator mount, the only drawback is that the nuts for the radiator mount holes are not there in their cages.

It will likely be easier to do it another way, and getting the correct core support year also makes it easier.

You would be better off doing a butt weld.  Hard to find a place that will overlap well.  Strongest is to drill the spot welds and separate the panels.  Did not take pictures of the ones I did takes time though and patience.  Be aware there was a change from early to late 521 radiator supports.  You need the later one sets the radiator closer to the grill.

[preventor5977]

Well, I did it.  I cut the old one out and welded in the new support.  It doesn't look the prettiest but it works and Ill figure out how to clean them up later.  I had to practice on the old support with the welder but got the right settings and got good penetration without blowing holes in the metals.  I stitch welded both sides as best as I could.  It was hard to not put in a continuous bead because I didn't want the metal to warp.  Once I figure out how to post some pictures, Ill get some up to show the progress of this project, along with the welds I did.  I do have to say the truck looks so much better now that the front ends been put back together.  I even got some of the chrome back in and put my headlights and ambers in.  Thanks Charlie 69 for the photo link.  Ill check it out and see what I can come up with.  

[preventor5977]

Sorry.  I meant to thank Jester for the photo help.  All the posts have really helped with this project though.

[preventor5977]

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[preventor5977]

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The picture of the welder is of the settings I used to weld everything so I wouldn't burn holes in the metal but still get good penetration.

[preventor5977]

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This is the old radiator support before I cut it out.  

[Jester]

Nice! Keep the updates coming. 

[preventor5977]

I definitely will.  The next project is the bed.  As you can see, it sits a little low.  Thanks for encouragement.  

[Jester]

What are your wheels off of and what size are they?

[DanielC]

Every 521 I have seen, the frame cross member circled in red is straight.

[wayno]

That's not a 521 frame Daniel, it's a 620/720 disc brake frame more than likely with mounts welded on it.

Every 521 I have seen, the frame cross member circled in red is straight.

[preventor5977]

Yup.  Thats what it is.  I got it this way with the disc set up on it.  The wheels are from an early 2000s Chevy Tahoe or GMC equivalent.  They are 17" rims.  I put the old tires from my Subaru on it from to get it on the road and get the spacing correct when I drop it.  

[preventor5977]

And the welding is hideous but its held together for a very long time.  I may clean them up and lay a nice over lap weld on them to make it look good.

[wayno]

Them front body mounts are hidden, so if they are solid, I would either smooth them out with a grinder, or just leave them alone.

I am kinda surprised about them front mounts, they are the only stock ones that line up perfect when swapping a 521 body onto a 720 frame, why they cut the original ones off is baffling to me.

And the welding is hideous but its held together for a very long time.  I may clean them up and lay a nice over lap weld on them to make it look good.

[Jester]

They probably started by just cutting everything off and didn't even check. 

[preventor5977]

Well judging where the truck came from, Im not surprised as to what was done and how it was done.  It was a daily driver that the guy needed to keep on the road.  The wiring is absolutely absurd under the hood.  Its going to take me a month to trace all the wires down and clean that mess up.  I need a picture of a stock 521 under the hood so I can get this mess paired down.