The Stovebolt Site Forums The Shop Area The Electrical Bay Voltage Regulator Fasteners

What is the correct type fastener for a 1948 voltage regulator to cab? Looks to be a sheet metal screw. Hex or clutch head? Is it a #12 screw?

The regulator was not installed when I got the truck.

Most of the replacements come with Phillips but the originals were clutch heads, #12 sounds about right.
http://www.flickr.com/photos/advance-design_parts_co/8129202876/in/set-72157631867396207

Brad -

Were clutch heads also used in '54? My aftermarket 12v VR is mounted with hex head sheet metal screws. Obviously wrong.

I replaced my VR cover similar to the one in your pic with an old Delco Remy cover that I got from a fellow 'Bolter. It helps disguise the 12v elec system on my '54. (except for the hex heads)

I'll check about clutch head being used in 1954, Lonnie.

I have a sizable collection of original and aftermarket voltage regulators. some of them have rubber grommets where the screws go thru, some don't. What is correct? Were there different kinds for different years? Was the rubber for vibration prevention?

A bit out of focus, but it’s a stock 1950, 3604, like Brad, clutch head screws:
http://www.pbase.com/dennygraham/image/148984564

What I believe to be a stock 1954, 3604, slotted head screws:
http://www.pbase.com/dennygraham/image/148984577


Denny Graham
Sandwich, IL

Yes Carl, rubber grommets for vibration isolation.

Dg

None of my Chevrolet truck and GMC 54/55 voltage regulator screws are clutch head.

All of mine have rubber grommets that the slotted screws go through.

I got to see before tear down photos of the '48 today. This truck was an original truck 3 years ago - original paint. The photos show pan head slot screws holding the regulator to the cab. This truck has a lot of slot screws where later years have clutch head. Maybe '47 & 48 had more slots form GM??

There are two types of clutch screw drives:
Type A and type G.

Type A, the original design, also known as a standard
clutch head, it resembles a bow tie with a round center.
These were common in GM automobiles, trucks and buses
of the 1940s and 1950s.

Type G resembles a butterfly. This type of screw head is
commonly used in the manufacture of mobile homes and
recreational vehicles and is the type that are being
marketed to us from the vendors today. I don't know
anyone who makes or sells the Type A now a days.

Your '48 would have had Clutch head screws as shown in
the links above.

DG

Hey guys, Thanks for the info on clutch head vs slotted and for the explanation of the rubber grommets on my mounting bolts.

The '47-'54 FAM shows slotted head screws to mount the VR. It's misleading for early AD trucks. An old post & pic on Stovebolt said that clutch heads were used in '54. Notice the difference in the location of the screws in the covers. The '47-'54 FAM and '54 Shop Manual show them through the top at two corners. I know that diagrams and photos are often shown for the wrong year.

Just to add to the fastener discussion, both the '50, and '49 'bolt, and my '49 Poncho used large Philips head screws to mount the regulators. Perhaps all were replaced!!

or all are of Canadian manufacture

Bill

Even though the FAM says, 1947-54 it is just meant to give you an over all idea of what
went where. A good portion of the illustrations are primarily aimed at the '54 model
years. You can't always tell if the same assembly ritual was followed for the earlier AD's.
All of the AD’s that appeared to be original that I've seen follow the fastener application
that we've been posting here. That is Clutch heads on the pre-54 models and slotted heads
on the post-54 cowl electrical units.
It would be very rare to find a 60-year-old vehicle that had the original VR anyway. Just
because the cover says Delco Remy doesn't mean that it is still the original VR. They did
make replacement parts also you know. Back in the day when I was working as a parts
man, the VR was one of the more common parts that was often replaced along with
rebuilt generators and starters, tires at 20k, points, plugs, cap & rotor at 8-10k.
We're so used to driving 80-100k without opening the hood or kicking the tires now days
that we forget that it took a heck of a lot more maintenance to keep these 50’s vintage
vehicles on the road.

Denny G

[quote=Denny Graham] Yes Carl, rubber grommets for vibration isolation.

I've often wondered about that.
As an electrician, I realize that they also isolate the Voltage Regulator from "ground"....

Actually the regulator case is grounded on the right side thru the two mounting screws:
http://www.pbase.com/dennygraham/image/149107869
I believe the grommets are for vibration isolation only.

Denny Graham
Sandwich, IL