Skyhigh82

New vette owner for two months now and I’m working on getting my 82 street ready. One thing I’ve find very frustrating is that I have to use metric/standard tools. I thought Chevy’s were made in America and use standard bolts. Just when you think is a ½” it’s 10mm. What gives?

mrvette

During the early/mid 80's there was a transistion time "GM and most companies went through on their tooling, some GM divisions, such as Delco, maybe Delphi back then, and Harrison for instance....had differant times they converted tooling over, AFAIK the original SB chebby blocks never were, so they used metric caps on 3/8-16 bolts....obviously could be subbed for 9/16 if you wanted to.....
I find in a pinch the only metric size commonly scene you can't sub an american 6 point socket on and usually move the bolt....is 15mm...that one they got you on....anyting larger, and so far I been lucky.....like lug nuts...

Usually the metric changeover parts were clearly marked as metric on the pans/castings......

GENE

markdtn

It's not just the early 80s. It is still going on. As platforms get re-designed they are increasingly going metric, but I have worked on 1999 stuff that still had both.

mrvette

Mark, you serious??? I have not seen anything out of the 90++ vintage with any 'American' bolts.....13-14mm---1/2-9/16 type stuff, but never an actual 1/2 inch from GM, you sure???

GENE

FinnShark

Metric is standard for me... :leaving:

mrvette

I wish they'd done the changeover some 50 years ago on this side/pond, as then I would not have had to deal with it.....

GENE

Jim Shea

1980 was pretty much the break point for mounting and connection points on most Saginaw high volume steering parts going to metric. Since the C3 power steering pump was standardized with all other GM pumps, it was converted to metric that year. However, the Corvette manual steering gear, flexible coupling, control valve, and the actuator stayed with conventional fasteners since they were scheduled to go out of production after the 1982 model year.

The pump discharge connection went from a female 5/8-18 UNF thread with a 45 degree flare face to a female M16X1.5 metric with an o-ring port configuration. The pump mounting holes and studs went from 3/8-16 UNC to M10x1.5.

vettemack

The metric system was approved for use in the USA in 1865. No typo here. It was not implemented because they lost the meter standard. I guess they found it in the late 70's.
Formerly USA certified in metrics,

markdtn

I put a water pump on a 99 "old body style" truck. That is the last of the 350 Vortecs so I guess they didn't want to get away from the std bolts. I'm pretty sure that it had 3/8 bolts holding it on, also the front accessories. I could be wrong, it's been a few months. I know on my 91 TPI 350 that the water pump, accessories, motor mounts, intake, transmission, and exhaust manifolds are all held on with 3/8 bolts. The balancer and lower pulley bolts are also std. Pretty sure the late LT1 used std bolts in the same locations (maybe not intake?). Other than engines there may not be many/any, perhaps the cover bolts on a late F-body differential?

Big Fish

I still don't understand why metric to start with. This is America, we speak english, and use the common feet and inches method of measuring.I think what this metric stuff is all about is foreign influence and the American jobs going elsewhere. Sorry, didn't mean to vent on anyone!

79Corvette02

I had a lousy freakin' metric nut on my transmission cable hookup at the tranny. That stupid thing drove me crazy until I realized the problem. Maybe it was the factory, more than likely it was Bubba, the previous owner, but regarldess, it ruined my day chasing down a hardware store that was open and carried that size. :smash:

TexasMadMan

I remember on my 82 CE and maybe my 80 model, a 15mm was required when working on the air conditioner and maybe the alt. It's been a few years since I owned those cars.

Turbo-Jet

in Canada, we have metric and non-metric. my car is 100% non-metric, except for the spark plugs :crazy:

Larry B.

The metric system is actually easier. It's the mixture of both that really screws thing up. My van has mostly metric except for engine parts which are SAE. BTW.. Money is actually metric...10 pennies=dime, ten dimes=one dollar. Ten tens in one hundred. ten hundreds in a thousand... What's so hard about that?

Jim Shea

It's interesting. The car companies beat on the supplier divisions to convert to metric. That's why you see metric fasteners on the steering and AC systems starting in 1980. However, 20 plus years later, you still find conventional (english) fasteners on their engine(s).

Do as I say, not as I do!!!! :yesnod: :nono:

mrvette

Jim, I don't really know for a fact, but I"d venture to say any new design engine like the NOrthstar and the LS1 are metric all the way,
I know the trannies like my 700r4 are.....

it's the old engine blocks been around for generations I don't think they ever actually changed the tooling around on.....like the SBC, maybe the BB too....

but all the inductions systems are metric.....the 3.1 v6, 4 cyl, all sorts of stuff I worked on that's new....or new-er, that is....

damn clock won't stop ticking....

GENE