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My 1971 521


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2 hours ago, mainer311 said:


I can tell you know a lot about bolts. “Pure” 

Jesus H.

You realize “stainless steel” is already an alloy, right? Does pure mean it’s never been fucked?

 

Common socket heads are 316 and 18-8. Gummy as hell. If those bolts back off at all, they’ll be in direct shear. We’ve been over this already. 17-4PH are exotic and stupid expensive, so it’s highly unlikely that is what they are.

You are smarter than me its all good, Ill run mine, Ill let you know when my engine falls out. Its been years now but will keep you posted when it does. All the Z guys run them also with a 6 cylinder also. by the way.

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20 minutes ago, mrbigtanker said:

You are smarter than me its all good, Ill run mine, Ill let you know when my engine falls out. Its been years now but will keep you posted when it does. All the Z guys run them also with a 6 cylinder also. by the way.

 

Oh, well, the Z guys run them. That must mean they're the gospel. 

Why would you even bother running stainless bolts? Because they don't rust? Neither does zinc plating on grade 10.9's. Ask Neil what happens when you run grade 5's on suspension components. 

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6 minutes ago, mainer311 said:

 

Oh, well, the Z guys run them. That must mean they're the gospel. 

Why would you even bother running stainless bolts? Because they don't rust? Neither does zinc plating on grade 10.9's. Ask Neil what happens when you run grade 5's on suspension components. 

Hey why do you have to bring me into this.... I only ran them for a week while the proper grade ones were being delivered.... I replaced those bolts so nothing bad happened...

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Marine applications all use stainless, and not of the super high quality. None of their stuff falls out either.

 

You guys are making too big a deal out of this.

 

I don't like stainless but that's because I like OEM hardware instead. It's got nothing to do with the strength.

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3 minutes ago, Crashtd420 said:

Hey why do you have to bring me into this.... I only ran them for a week while the proper grade ones were being delivered.... I replaced those bolts so nothing bad happened...

 

I thought you had a grade 5 snap or something weird happened? No?

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About 55,000 per square inch. A 3/8" stainless bolt will need about 5,500 pounds at right angles to shear it. Enough to support two 521s. Steel would be about 9,200 pounds.

 

L20B weighs about 270 pounds plus some from the front of the transmission.... say an even 300 pounds. The engine brackets are the most at risk for right angle shear and there are 4 bolts. If the truck dropped vertically one foot the L20B would feel like a 3,600 pound weight (don't forget 4 of them).... if it stopped instantly but it has 8 or 9" of suspension travel to cushion this so 450 pounds over 4 bolts.

 

Hey This is a guesstimate. Any engineers can argue these numbers.

 

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I just think installing inferior bolts because they won't rust is a poor reason. Marine and food industries require it because of corrosion. We use stainless in all outwards-facing fasteners on our robots because of military requirements for corrosion. 

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I replaced the L20B cast exhaust manifold studs for holding the down pipe with stainless. Years later came back and they were covered in baked on dirt but easily unscrewed. The original ones didn't have any threads left above the nuts. All rusted/eroded away.

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18 hours ago, mainer311 said:

Trans takes the same as the 4 speed. Any GL-4 gear oil. Nissan still sells it, or you can run synthetic Redline MT-85 or MT-90, Amsoil Manual Transmission fluid, or Sta-lube. Can be kinda hard to find. Everyone carries GL-5, but GL-4 is “outdated” and kind of a niche item. I run the same Nissan oil in my manual trans Xterra as I do in both my roadster and 521 transmissions.

 

I would run any cheap ass name brand dino oil, and add some zddp or other break-in additive to it. Most local places will have Lucas zinc additive. Don’t run synthetic the first time around. You want there to be a little bit of friction going on between the rings and cylinder walls so that they bed in properly.

 

This for the trans and steering box?  Anyone know many liters each takes?

 

https://www.amazon.com/CRC-Sta-Lube-SL24239-Multi-Purpose-Hypoid/dp/B000M8RYMC/ref=sr_1_1?crid=1DHKEKGSJUK89&dchild=1&keywords=gl-4+gear+oil&qid=1608586579&sprefix=gl-4+%2Caps%2C159&sr=8-1

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1.7 liters (or 3 5/8 pints US) for the stock F4W63 4 speed, and 2 liters (4 1/4 pints) for the 71B 4 and 5 speed. Probably cheaper by the gallon and in 30K miles you have no excuse for not changing it.  DO NOT over over fill, it will only foam out the breather and make a mess.

 

Steering box is 0.33 liter, so minimum 5 US pints will do it.

 

I use 2' of garden hose with a small funnel in the end. Feed it down from the engine compartment and into the fill hole. (usually on the right) If cold out warm the oil in it''s container in a sink of very hot water for 20 min and it will pour faster. Expect it to drip and run out when full and have someone pull the hose out and quickly put the bung in. Wipe and then spray it and the drain bung down with brake cleaner so if it's leaking later you will know.

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7 hours ago, Stoffregen Motorsports said:

Marine applications all use stainless, and not of the super high quality. None of their stuff falls out either.

 

You guys are making too big a deal out of this.

 

I don't like stainless but that's because I like OEM hardware instead. It's got nothing to do with the strength.

Thank you , I prefer titanium or a black bolt to be honest, but hard to find, cost is one thing but to find in all different thread pitches and what ever is a bitch. 

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Titanium specs and it's most common usages.

 

1 extreme cost for showing everyone that you care more about the display of wealth than all the other considerations.... bling

2 extreme corrosion resistance

3 extreme strength even at high temperatures.

4 extremely light weight about 1/2 that of steel.

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9 hours ago, datzenmike said:

Titanium specs and it's most common usages.

 

1 extreme cost for showing everyone that you care more about the display of wealth than all the other considerations.... bling

2 extreme corrosion resistance

3 extreme strength even at high temperatures.

4 extremely light weight about 1/2 that of steel.

I like the first one. except i'm not wealthy.

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