So in pulling apart my fuel system to swap out lines I've discovered something unexpected. (Well a couple things really.)

The bolts throughout the truck seem to be in two different standards (SAE and metric). Really? Did they not make the whole working on the truck thing hard enough as is?

Also, was there some kind of fight between the engineers and management? In replacing the midship flex-lines I found that the sending unit could have been moved up about 4" (there's mount holes for it even!) that would have made it easier to swap out those lines (as in I wouldn't have had to drop the tank to get to the rear pinch clamp). That and the double standard sizes is what makes me wonder about engineer/management relations at the time.

 

Considering the truck is 20 some years old, its quite possible someone has had it apart before and just used whatever bolts they had available for reassembly. I know I have been guilty of that in my younger days.

 

It was actually very common in the '80s as domestics were moving from SAE to Metric part by part it seemed.. GM was the worst but my truck is the same, and I know mine is original still.

 

Some years back I had to change the clutch in my '81. At that time I had only a few mm tools from even more years back in the motorcycle days. The crossmember had 18mm bolts attaching it. I was dumbfounded at that. Had a difficult time finding a 18mm socket or wrench but those are the only mm fasteners I've found on the truck. I got my '87 DeVille about 10yrs ago and I've now got as many mm tools as I do sae tools.

 

That's your government at work for you. Do you remember back then when they mandated the US was going to go to metric? When they did that, they didn't redesign what they already had, so when it was used, it still uses standard bolts. You will usually find standard bolts where they thread into the engine. This applies to the older engines, since when they did a major re-design, they usually went with metric in the engine also.

So if you have one of the older 1960's style engines(300, 302, 351w, 351m, 400, 460, etc) you will find a mix of metric and standard bolts. If they did a new bracket on the engine, it will have a metric bolt in it somewhere if it doesn't thread into the engine, but where it's mounted to the engine it will have a standard bolt.

Most of the body fasteners will be metric also. If you get into the front or rear axles, you may find some standard in there. You also may have a metric bolt, and not even realize it. Nothing fits a bolt with a 10mm head, but 11mm is the same as a 7/16 wrench, 13mm is close to the same as a 1/2, 14mm-9/16, etc.

About the accessibility of the parts; They didn't design vehicles with repair work in mind very much. Their main priority was ease of assembly on the line. If they could save a couple of seconds per vehicle in assembly, that was their priority.

 

Interesting. I never knew they mixed fasteners that way.

 

The bolts holding the trans cross member in on these trucks are 5/8 on the head, and the nuts are 18mm... LOL

 

At least on my truck, the bolts that hold the tank straps have 1/2 heads, with 16mM nuts holding them on (I nearly rounded one trying to take it off with the wrong size SAE wrench).

According to the previous owner (truck has had 3 owners, a father and son pair and me and the son is one of my closer friends) the truck is all stock (well until I get done swapping out nuts and bolts >.< and it a grab bag of SAE and metric. The engine is all SAE except one bolt which is metric, and everything else is apparently mix and match.

That hardline and mount point for the sending unit slays me though. In the future I swap out the hardline with a longer version and move the sending unit up. Probably when/if the sending unit ever goes bad, or I find that I need to replace the sensing units in the tanks (since both don't bother reading fuel levels).

 

http://www.metrinch.com/

 

Franklin hit the nail on the head. Or should I say Bolt?

It was the great (Government imposed) move to metric measurement that caused alot of the mix and match bolts and nuts. It also caused the multi standard speedometers, you will notice it reads miles and kilometers etc...

Everything was going metric. Not just the bolts on your truck were changing. The road signs were changing from miles to kilometers. How you paid for your groceries was changing from pounds to grams. Even how you paid for your fuel was changing from gallons to liters.

There was a major uproar with the public at the time. One of the biggest complaints, was with Fuel stations at the time, that were going metric. Gasoline was about a $1.30 a gallon due to the 1979 energy crisis. Close to about $5 in todays money. When metric came out people thought they were getting a good deal at 80 cents a liter. However, when they found out a gallon is a lot more than a liter, they complained. Thus one of the reasons why the mandated move to metric, here, was never completed. Thanks to the unscrupulous people at the time.

 

As well as a few other things...

The cake recipe that used to require 2.5 cups of flour now required 350
grams of it.

The bag of Scott's Turf Builder that used to cover a 1.5 acre yard now only
covered 0.6 hectares.

The car that used to get 15 MPG now required 18.8 liters per 100 kilometers.

Guys who used to wear Size 11½ shoes now had to find 'em in 28¾ centimeters.

Oh, yeah....

 

Still is in my book ...

-Enjoy
fh : )_~

 

Try a 15mm on the 5/8 next time.


Try a 13mm on the 1/2 head next time. Though if the 13mm bolt is rusty and little disintegrated, the 1/2 wrench works well, since it's just a tiny bit smaller, and will have a more snug fit.

 

Dear god, i read this, and, i feel like im back in math class........... PLEASE MAKE IT STOP!!!!

 

Franklin, it's definitely a 5/8 head, 15mm is too small... Just one of those weird things.