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A 521 in Massachusetts


Crashtd420

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And Wayno I do have the extension on the driveside with the charcoal canister under it.....

I guess I'll look at those leaf springs and rear diff tonight... I may have been a bit quick with the comparison.... I though I counted the leafs on each pack, but now i question that... for all I know one of the diffs could have been upside down and that's why they looked different.... pics will prove....

Which of those diffs would be better? Currently using what came with the truck...

I do plan on changing my 4 speed for a short ZL71b 5spd....

 

OK, so that box was on a truck that came with an L block.

You don't have to change the whole differential to change your gearing, you only need the center drop out piece(pumpkin) that has the gearing you want, your 72 should have 437 gears, personally I would leave them in there with an L16 engine, the L16 is not known to be a torque monster, it is a higher revving engine, if you had an L20b it would depend on what you use it for, if you haul weight around all the time, leave the 437s in it, if it is a daily driver driven like a car I would likely go with 411s or 390s, but that is with an L20b installed in it.

Is this the one with the built L16, if it is I have no idea what gearing you should have in the rear, my L16 would not push the truck thru the air in 5th gear at 70mph(it had a dogleg 5spd. when I bought it), I was floored all the time trying to do freeway speeds, I converted over to an L20b when the freaking truck with an L16 would not follow my friends trucks up a logging road hill to fly our hanggliders in first gear, after the L20b was installed I could go up the same hill in 2nd gear.

These trucks are old enough that someone could have changed out the leaf pack or removed leafs, a photo would help to determine that, are you wanting to lower it, if you plan to then you want 4X4 720 leafs, if you are keeping it the height it is then leave what you have on it.

Where are you getting the 5spd, does it already have the L case on it?

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Gonna try and hit on everything you said...

First.... yes mine is the built l16 and even the slug it was before I liked the 71b trans behind it, 5th on the highway wasn't bad.. had to down shift to 4th on a hill but again too wasn't bad...

basically I got my 521 with a locked up trans.... i got the 71b because I wanted a 5spd, but it had the wrong bell housing on it,so I drove around with it crooked.... when I did my rebuild I bought and installed a correct working 4spd...

I almost sold the 5spd till I was told I can swap the bellhousing, which I have recently purchased... so that's where it sits waiting.. once I'm back on the road I'll do the bellhousing swap and then run the 5spd....

 

As far as leaf springs I'm as low as I'm going. I used the ones from the trailer because it only had 5 leafs in it, my original had 7.... I only mention them as a possible way to identify the trailer, i used them thinking they had a lighter duty spring rate...

 

And last the diffs....

I know there s a way to count the rotations and determine what they are...

Probably do that tomorrow.. can't find any markings....

 

This is the diff from the trailer..

 

20171115_163607.jpg

 

 

20171115_163601.jpg

 

 

20171115_163551.jpg

 

And the diff from the truck and what I am using....

 

 

20171115_160828.jpg

 

20171115_160816.jpg

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What I do at wrecking yards to double check the gear ratio is pin one side/wheel so it cannot move, then I turn the other wheel 2 complete turns while counting how many times the drive line turns, if it turns 4 and one third turns it is a 437 gearset, if it almost turns 5 times it is a 488 gearset, if it turns 3 1/2 times it is a 3.50 gearset, do you see what I am getting at, if you cannot turn the tire in the air(not pinned) it is either in gear, the e-brake is on, or it is some kind of LSD/posi(welded or real one), but the odds of you having a LSD are way up there in the winning the lottery odds.

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So wayno... i'm really hoping I won the lottery here ..

I've been trying to identify the 2 diffs I have.... talked with dp and he has one that looks like the unpainted one in his 71 521....

 

The only pics I can find that look like mine, the black painted one, say it's a h190 LSD ...

This is what I found....

Screenshot_20171116-121547.png

 

I found a couple others that look the same and claim LSD but this was the best pic..

The only thing i see different is the output flange...

So does anyone know what I have?

How can I tell lsd or not?

I'll be checking the gear ratios when I get home? Will that tell me anything other than gear ratio?

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The housing has nothing to do with it being an LSD or not.

Well i never do win.....

I always assumed I had an open diff, i was hopeful.... and verified yes it is open..

 

And by the Wayno said to count for the gearing the black diff in my truck has 4.37 gears....

 

And the unpainted one from the trailer has 4.88 gears

 

So I'll just be leaving things alone...

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None of it makes sense to me... every time i try to make sense of something someone contradicts what I thought I figured out...

Even the pics wayno posted confuses me because the one he says is lsd looks like mine but mine is not....

 

If you can turn one wheel while the other wheel is on the ground you do not have an LSD.

They all look the same on the outside except very early H190s had alloy cases and somewhere in the 620 run they changed over to steel cases, a 1990 hardbody H190 gearset(drop out pumpkin) will fit into the 320, 520, 521, 620, and 720 H190 axle housing, the trucks are all the same except for the 85/86 Nissan 720 4wd trucks, they came with the C200 axle.

I would have to see a photo of your gearset that you say looks like this photo below which is an LSD gearset.

DSCN1637.jpg

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It was the front case that looked the same... I have no intentions of opening the diff I have....

I did the one tire in the air.... tire spun, open diff....

Also read with both tires in the air spin one if they spin opposite open , same direction lsd....

Still open...

oh well I am still learning things.. like now I know I have the 437 gears...

What that means I don't know...

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It was the front case that looked the same... I have no intentions of opening the diff I have....

I did the one tire in the air.... tire spun, open diff....

Also read with both tires in the air spin one if they spin opposite open , same direction lsd....

Still open...

oh well I am still learning things.. like now I know I have the 437 gears...

What that means I don't know...

 

It means that going 70mph down the freeway your engine will be turning around 4000rpms, a lot of drivers on here don't like to hear the engine turning that fast, but that is the way they were made, my work truck has been turning 437 gears for over 20 years without any issues that anyone could point to the rear gearing and say that was the issue/why it broke.

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Well i never do win.....

I always assumed I had an open diff, i was hopeful.... and verified yes it is open..

 

And by the Wayno said to count for the gearing the black diff in my truck has 4.37 gears....

 

And the unpainted one from the trailer has 4.88 gears

 

So I'll just be leaving things alone...

J13 520s & 521s had the 4.88 gear ratio, with the L16 came the 4.37 gear ratio.

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I figured i'd give everyone a good laugh..

Installed a cabin air filter in my 521...

 

 

20171116_171818.jpg

 

Basically I don't have that air duct or what ever that is that connects to front blower motor... my son kept trying to turn it on and stick his hand into the fan so I had to do something... I'll probably atleast get a shorter one eventually...

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That is another rubber piece I have thought Clauss Studios might possibly make someday if anyone made the effort to send him a good sample, I bet that he could sell quite a few of them unlike the wiper motor seal which would not sell well in my opinion.

Ya I'm starting to run out of original part, during assembly i've been finding there are parts i am missing that I didn't even know I was.... I'm have more fun building and ratroding the missing pieces....

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Leave the vent there, it's not hurting anything.

Nice fab job, no one would know it's not stock.

Thanks...

And as far as the vent I was just thinking about the possible gas smell just venting to open air.. its not even noticeable but I was just thinking if the gas cap acts as a vent now would that be better than leaving the vent open?

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