Introduction: just bought a '73 620

[Roadracer Al]

Hey there!

 

About 3 weeks ago, I bought a '73 Datsun 620 Pickup. The body is pretty straight, but very rough - the DPO (dreaded previous owner) rattle-canned it flat black primer (not even flat black paint), and prior to that it was sand blasted along with portions of the windows and all the trim prior to painting baby blue. I'm hoping that I can just wash off most of the primer with lacquer thinner, but that's really the least of my problems.

 

The DPO claimed that a recently rebuilt 2-liter motor and usable 5-speed was installed. I have yet to verify that the motor is a L20, but it definitely has a 5-speed. It makes a horrible racket when using engine braking, so I suspect it may need rebuilt. The carb looks pretty crappy, I see a webber in my near future.

 

First up are the brakes, which are full of rusty crap and dissolved rubber. I just ordered a new master cylinder and rebuilds for the wheels -- hopefully, the wheel cylinders will be in good shape. It also needs the e-brake fixed.

 

It's never going to be a show truck, but it would be kinda nice to get it all one color. My daily driver is a '02 Camaro convertible, and I need to quit treating it like a truck, so I got the 620, which just needs to be reliable. Believe it or not, my wife thinks it's cute as a button, and is behind the project.

[moparvwfreak]

welcome to our little corner of insanity :D e-brake cables can be gotten off fleabay or some parts houses may be able to get em. the hardest part is getting the drums adjusted right. its kind of a PITA to get right. but once you do it feels so good.

 

to verify the motor, if you havent figured it out, check in the passenger side ofthe block, right about the #3 cyl. there should be a boss that has the engine code on it. IF it is a 2.0 it should say L20B on that boss. that way you can know. i am doing the same swap on my own blue 73 620.

 

as for the engine braking, check the valve clearances. that might be the main issue. also you should try to find a factory service manual. a 74 will do in a pinch. heres a link ot get one as a PDF format. http://olddatsuns.com/620tech.htm . its at the bottom of the page. that got me through an assload of issues starting out.

 

oh and we like pictures, so cough em up :) lol!!!

Edited October 2, 2009 by moparvwfreak

[pharouh]

Welcome!

DPO.. I like that! All too familiar. Mine took the back seat out of a minivan and set it on the floor to use instead of the stock seat. comfy-but not bolted down!

I just bought a 73 around labor day.

We want to see pics and lots of them.

[Roadracer Al]

Hmmm. Minivan seat. I like it. Those are probably pretty cheap down at ye olde JY. I'm a pretty decent fabricator/welder, so mine WILL be bolted down properly. The DPO has some bucket seats in there now, but they're way too upright because he couldn't get the bolt holes to line up. I'll just tinker with those for now until I get it running properly/safely.

 

The truck did actually come with a Haynes manual, it shows where the designator for the engine and trans are located - I just haven't verified it yet.

 

I was kind of hoping that the e-brake wouldn't need to be replaced, just adjusted or repaired, but we'll see how that goes.

 

RE: funny noise on engine braking, it seems like there is something rubbing/whining, definitely not valves in the engine. I'll do the gear oil/atf trick and see how that goes.

 

Oh, yeah, the other major drag is that when I fill up the gas tank, it leaks like a sieve - I haven't got under it yet, but it seems like the filler hose is rotted out. I'm hoping I don't have rust holes in the tank - fixing rusty tanks is a huge drag. Is this a common problem?

 

Here's a pic that a friend who really likes Hot Rods gave me - it's been photoshoped (obviously). BTW, I have to say, the turbine wheels are kind of growing on me, but I can live without the whitewalls. :D

 

[moparvwfreak]

my 78 did that when i first got it, but only a couple tanks then it went away. so i dunno what the issue was. might just be the tube might have shrunk a little due to age.

[Roadracer Al]

Yeah, something needs to get fixed - the thing stinks of gas, and there's a large dark stain under the truck, f'ing up my concrete driveway. :mad:

 

I scored a rebuilt master cylinder after one of the local auto parts chain stores couldn't find the correct master cylinder rebuild kit --- the cylinder was only $10 more than the rebuild kit. It requires the reservoirs be swapped over, which was an easy job. I'll be getting that installed today and I can get along with the rest of the wheel cylinder rebuilds.

 

Does anyone have any advice on getting the drums off? I had the rear wheels off to try and bleed the brakes, but the drums wouldn't come off. I wailed on them with a rubber mallet, but they didn't want to budge - you could see where the DPO had attempted to pry against the back plate, mangling it (thanks a bunch for YET ANOTHER thing to fix :fu: ). I was thinking of going to Horrible Freight and buying one of their big-ass slide-hammer/pullers, which has a hook attachment.

 

Thanks in advance for any advice you might have.

[Z-train]

SLIGHT possiblity that the noise on decel is the carrier bearing.

[DISLEXICDIME]

back the brake adjusters off !

There are 2 bolt holes in the drums (be careful) they strip find the right size bolt tighten it down just a little then tighten down the other bolt a little bit. If it dont budge smack it with a hammer till it moves then repeat till its off

 

If all ells fails take it to the brake shop and let them deal with it.

when i did mine i had to use a mini sledge the rubber mallet didnt do the job

[Roadracer Al]

Thanks, I'll look at the adjusters, and look for the bolt holes.

 

Discovered the source of the gas leak... tank's rusted. DPO had put a big-ass ball of JB-Weld around the drain. Lucky me, I get to drain, remove, de-gas, clean and weld on my gas tank. I do this frequently on MC tanks, but they're a lot easier to get off and handle.

 

RE: noise - cool, I'll probably throw some U-Joints into the driveline, and I'll put a carrier bearing in while I'm at it. It might have Cardan joints since the trans was swapped.

[Roadracer Al]

"Real" work was slow today, so I had a big work day on the 620.

 

I welded up a hook-type slide hammer (ironically, from an axle I found in the basement of our new-to-us house) to pull off the rear brake drums, which were frozen in place. Sure enough, the star adjusters were rusted up, the pads down to the metal, and the wheel cylinders oozing brake fluid. I can't believe I drove it 2 hours home this way.

 

While I was working on the rear end, I took out the 3" drop blocks and cut them in half. That should provide some much-needed ground clearance. I'll make the front match shortly -- I think I'll have to cut the existing bolts because they'd hit the driveshaft.

 

Moving on to other problems, I went to check the rubbing sound on the drive line. Wow. There is NO CENTER BEARING. Z-Train, you hit the nail on the head! The drive shaft flops around loose in the center bearing holder. I assume it was installed this way during the trans swap.

 

I recall seeing a post saying that the easiest way to make a 5-speed swap work is to score the matching driveshaft, but that the center bearing support needs to be moved rearward about 1/2", I'll have to look into this after getting the replacement parts.

 

I decided to yank out the seats to have a look at mounting them better, and to clean up the carpet and floors -- I'm always pretty sketched by the stuff under a used car seat. :eek: It's gratifying to clean up a filthy old beater.

 

One thing I know definitely happened in the trans swap was the massive hacking on the floor pan. It looks like someone went nuts with an air chisel. I have to post pix, it needs to be seen to be believed. I think I'm just going fabricate a whole new trans tunnel.

 

I also noticed a pretty large crack from what looked like flexing in the body under the passenger seat?! Is this a known issue?

 

PS: Oh, and I forgot to mention -- the tanks not rusted, the truck was so slammed that the drain bolt hit something and cracked the tank.

Edited October 7, 2009 by Roadracer Al

[skunk]

cool little truck, i just got mine too, its a 73 as well, hey if you end up not wanting thos rims, id love to buy them off ya.

[Roadracer Al]

Hey there Skunk - like I said, they're growing on me, they just need some cleaning. I'll probably flip the black-wall side of the tires to the outside -- the tires have plenty of tread left (but the spare is bald as a cue-ball & needs replacing).

 

Ordered some bits today from AutoZone. Yowch - the center driveshaft bearing (I'm amazed they had one) was $106. Looks like I have to take the driveshaft apart to install it.

 

The upside was that front brake shoes were $14. The downside about the shoes is that they don't have the rears. I'll check Kragen.

[datzenmike]

Yeah post pictures. The cracks are not a usual problem. Maybe the hack job on the tunnel removed some of the rigidity causing the body to flex. The torsion bar adjusters should not have hit the driveshaft! Usually the center bearing never goes bad. What usually happens is the rubber dough-nut surround rots away and allows the drive shaft to wobble and bang around. Just find a replacement rubber. This will cause all kinds of noise and vibration. If this is the case maybe the drive shaft did indeed hit the torsion bar anchor bolts. Check that the shaft isn't bent or damaged. I hate people who modify (read 'drop') and don't think it through enough and almost tear the drain plug off on a manhole. Idiots!

 

Don't forget pictures of the tranny.

[Roadracer Al]

Well, heck. I wish I'd known that the rubber part comes separately from the bearing, that would have saved a bundle of cash, no doubt. A little busy today, I'll get pix in the next couple days.

 

Heh... the wife said today "Yeah, I still think it's cute, but if it's sitting in the driveway on blocks for 5 months, I won't think it's cute anymore."

[Steroid]

Hi Al and welcome!!! Where are You located?? Lots of Us on here to help!!

 

BE CAREFUL if You purchase new emergency brake cables. I just discovered while building My dually that there are at least 3 types. OBVIOUSLY, the longbed trucks are longer so there are 1 to 2 different ones there. And earlier trucks bolted up differently than later ones so 2 more. I had to replace one on the passenger's side of Choptana (which is a 1979) and had to use the only matching one I had (a longbed cable) resulting in it running OUTSIDE the frame. We should actually start an E Brake cable thread on a sticky later. Good luck and a year from now You will look back at Your thread and say "WOW!!! I got all of THAT done?!?!?!".

[datzenmike]

E brake cable assembles:

 

RH up to 07 '77 short wheel base................... # 36500 B8001

LH up to 07 '77 short wheel base................... # 36510 B8000

 

RH 08 '77 on, short wheel base...................... # 36500 B9800

LH 08 '77 on, short wheel base...................... # 36510 B9800

 

RH 09 '74- 07 '77 long wheel base.................. # 36500 B8901

LH 09 '74- 07 '77 long wheel base.................. # 36510-B8900

 

RH 08 '77 on, long wheel base....................... # 36500 B9860

LH 08 '77 on, long wheel base....................... # 36510 B9860

[Roadracer Al]

Thanks for the part numbers. I'll store that for later use. I need to get the normal brakes working before I dive into the e-brake. I didn't see dangling cables when I looked at it, maybe the brakes were just so gone the e-brake just wouldn't work. Maybe I'll get lucky on that.

 

I got pix of the crack, and welded it up already. I figured out what made it: when the DPO put the seats in, he cranked down on the mounting bolts, putting pressure on the floor pan, which flexed and eventually cracked.

 

I expect to find similar damage to the other side.

 

Here's a before and after. You can actually see the crease in the floor pan which caused the cracks. The pix are from different angles, sorry.

 

 

 

PS -- Oakland, CA. I've edited my profile.

 

PSS - Forgot to add the hacked trans tunnel pic. It's a doozie. At the very least, I need to spend some quality time with a slapper & dolly to smooth out the sheet metal, and weld up the unwelded seams. I haven't yet figured out which trans this is or what it was out of, so I don't know if it is a common swap. You can see the trans is actually contacting the floor pan at the front. Also, there are two mounting ears right below the shifter that don't meet up with anything. Shouldn't there be a cross brace?

 

Edited October 9, 2009 by Roadracer Al
Add trans tunnel pix

[datzenmike]

I don't think that's a dogleg. Looks like an FS5W71B made before '80. Those ears aren't used but there should be a cross brace in front of those.

 

This is just a picture to illustrate the mount position.

 

http://i138.photobucket.com/albums/q251/datzenmike/Tranny/transFS5W60A81210-1.jpg[/img]"]

 

The 'ears' are below the shifter but the truck tranny mount is about 6-8" forward of that.

Edited October 9, 2009 by datzenmike

[pharouh]

Wow! That is a big ass hole in your floor!:eek:

[slam_dat_sun]

Wow! That is a big ass hole in your floor!:eek:

 

I don't see any ass holes in his floor :lol:

[yello620]

 

PSS - You can see the trans is actually contacting the floor pan at the front. Shouldn't there be a cross brace?

 

 

I am betting that you still have a shorttail four speed crossmember in there, and you have a long tail five speed trans. The shorttail crossmembers were flat across there surface and the longtail crossmembers were offset down about 3/4". This would bring the tail of your trans down away from the cab sheetmetal.

[Roadracer Al]

Thank you, Mike, that definitely looks like the trans I have. Yello, I'll have to see about those mounts, that sounds like a strong possibility. I haven't eyeballed the alignment between the trans and center bearing, I'm betting it's badly off, hopefully the right direction.

 

Regarding the front suspension torsion bolts, I think they'll have to be shortened to get some ride height back in the front because the trans swap has put the tail end of the case right where the torsion bolts need to be.

 

Today I dropped the gas tank to fix the leak.

 

Also, I take back most of the hate vibe on the DPO -- the tank wasn't damaged due to being lowered, it just rusted out the good old fashioned way. He still gets a dope slap for the big-ass ball of JB Weld. I have to fish that out of the trash for pix, it's pretty entertaining, I'm not kidding when I say it's 1/2" thick.

 

I got a patch panel made for the tank, but haven't welded it in yet. Ironically, the only sheet metal I have on hand is stainless. So the tank will now never rust out in that spot again. :cool: I'll post pix tomorrow.

Edited October 10, 2009 by Roadracer Al

[Roadracer Al]

Wow! That big ass hole fubar'd your floor!:eek:

 

Fixt.

 

Yah, pretty much my feeling about whoever did that hack job.

 

I just don't understand why they made the hole go so far to the rear. And why they made no effort to close up the front. Or, for that matter, why they thought it was a good idea to close up the radius of the tunnel.

 

Once I get the brakes & tank working/not leaking, I'll run down to the local metal joint & buy some 20-ga. sheet and put together a complete new tunnel. It's probably less work to just remove the mangled one completely and start over instead of hammer & dollying that mess into shape.

[yello620]

Thank you, Mike, that definitely looks like the trans I have. Yello, I'll have to see about those mounts, that sounds like a strong possibility. I haven't eyeballed the alignment between the trans and center bearing, I'm betting it's badly off, hopefully the right direction.

 

Regarding the front suspension torsion bolts, I think they'll have to be shortened to get some ride height back in the front because the trans swap has put the tail end of the case right where the torsion bolts need to be.

 

I'll post pix tomorrow.

 

Take a pic of the trans crossmember, we can tell you if you have the right one for a longtail tranny.

 

And the trans swap should not be affecting anything to do with the torsion bar bolts IF you had the right crossmember.:D

The bolts should clear the tail of the tranny when it is lowered down into the proper spot.

[Roadracer Al]

First, the good news: Kragen can get me the rear brake shoes, and they're only $14 for the set. Be here tomorrow.

 

The bad news, I've been busy doing "other stuff" leaving very little time for wrenching on the 620.

 

I did get the patch panel for the gas tank all welded up. Let me just take a moment to say "MAN, I miss my TIG welder!!" We moved to Oakland this past winter, and the house doesn't have 220v, so my TIG has been gathering dust in my shop.

 

Here's a buncha pix of the tank fix.

 

It's looking like a beer commercial because I just rinsed the tank out for 45 minutes with the garden hose so I wouldn't blow up my garage.

 

 

What the rust holes look like after a good wire wheeling.

 

 

Always a good sign when the rust doesn't extend to the edge of the patch.

 

 

The hand-hammered stainless patch and the original drain bung cleaned up on a lathe.

 

 

And the finished product. I know, the welds look cold, but the tacks kept blowing through, so I kept turning the spot timer down, and the amps down. I probably could have turned the amps back up for the seam weld and moved the gun faster. Like I said...I really miss my TIG!

 

 

Edited October 12, 2009 by Roadracer Al
speeling.