The Stovebolt Site Forums The Parking Lot Big Bolts 1965-1966 GMC Medium Duty Truck VIN Question

I spent much time this morning trying to "decode" the VIN number for a GMC 5500 medium duty truck. This truck was originally purchased in 1965, but is probably an early 1966 model. The VIN is HM5670VD1279E. Can anyone interpret this or tell me where information about mid-1960's GMC medium duty truck vehicle identification numbers can be found? This all started with trying to find hood latches, only to discover that the truck model year is in doubt.

JRMunn

Welcome to the "'Bolt"!! I tried oldGMCtrucks.com,and couldn't find info on your particular year. you may E-Mail: [email protected],and he says he'll get back with you within a week. Just make sure that you clearly state that your topic is G.M.C. related,or he'll automatically delete it. Hope this helps! Check-out "The Big Blue Truck",(Paulybuilt),on "youtube"! You'll LOVE it!! 1965 G.M.C. 4000!

Wetwilly,

Thank you for the reply. I had looked at the oldgmctrucks.com site, but didn't VIN descriptions for mid-60's models. I sent the suggest message and will wait to see how it turns out.

Thanks again!

JR, take a look around Jollys site, he has some 60-66 GMC ID info

Bill

Bill,

I tried Jolly's site and went back using your link (it worked better than my web search). This site does a great job of identifying trucks up to 11,000 lbs. GVW. My model 5500 medium duty truck has a GVW of over 19,000 lbs., the model isn't included, and the VIN sequence is different. I am hoping someone knows more about VINs for the mid-1960's medium duty trucks that seem to fall between information available for light duty trucks, older trucks, and the establishment of standardized VINs.

Jollys site has been undergoing changes, appears to be up again in multiple places - how about info here? appears your truck is a '66 [the D]

Bill

Bill,

Thank your! I don't know how I missed Jolly's VIN page for larger trucks. It isn't perfect for my VIN (no description for the "M" designation, my truck is not 489" long so the wheelbase calculation must be different, and my serial number sequence only has 4 instead of six digits on a 1996 model). Maybe the truck was made in Canada? But this is good enough for what I need. And there is no doubt about the truck year and model since the cab of my truck looks very much like the white truck in the next to last photograph at the bottom of the web page.

Thank you again for the help!

JR,

I found out a little bit of info on the numbers that I mentioned I would check for you in my books. I posted it over at your other thread on "Hood Latches".

I just checked over at Jolly's site myself and could not find much at all over there for your truck. I want to point out that it may be a little confusing as even though your truck is the new style "HM", they also still made the older style Conventional Cab that year as well in '66. They are actually designated as the "F" Model, but everyone just knows them as the '60 to '66 style.

If I missed something over there or if you can find out any other info, just let me know.

Bill

JR,

The white truck that you are referring to over at Jolly's is actually a GMC 7500. Even though there are a few differences, they made them for many many years up till somewhere around 1980.

Also note that the 7500 has Wider Fenders. Compare it to your truck and you will notice the difference. Your 5500 should have the Narrow Fenders.

Bill

Bill,

Thanks for the additional information. My point about the white truck on Jollys site was that the cab style looks like mine. I agree that the fenders on my truck are probably not as wide as in the picture, although they seem wide when I stand next to them. I think I know what I need to for the time being - until confronted by the next problem, like how to adjust the driveline brake so I don't have to turn the truck off to open gates.

Let us know what exactly what type of E-Brake you have. Some can actually be adjusted from the inside.

Bill

Bill,

The parking brake on my GMC 5500 is a handle about 16 inches (I am guessing) long that is mounted on the left side of the cab and pulls straight up. I have not seen any screw adjustment for the brake cable in the cab. I just got the cable unstuck (with lots of WD40 to be followed with a real lubricant) a few days ago, so am now trying to figure out how to tighten it.

Underneath, the brake is a shoe that goes around a hub behind the transmission. It is divided into upper and lower halves at a solid bar on the left side that is bolted to the transmission. There is a lower adjustment nut below a large spring on the lower, right side. This seems to mostly adjust the lower shoe. The upper shoe needs to be tightened, but I have not been able to find the adjuster for it. An experienced mechanic told me a couple of days ago that there should be an adjustment bolt or nut on the upper, left side of the tightening mechanism, but this is pretty much out of sight from below, and I have not had a chance to try to find it yet. I hope to take a look tomorrow, but not until after an appointment to have the VIN checked - so I will be turning the engine off to use it as a brake when opening and closing gates. I would be grateful for any advice about this.

Sounds like the handle is attached to the dash board. If that is correct, look to see if there is something like a "Cap" on the end of it. If there is a Cap, try twisting it. If it turns, that could very well be your adjuster. Also, if it is, turn it a little then pull up on it, then repeat till you get it just right. Otherwise, check under the truck as your mechanic has suggested.

Bill

Bill,

Thank you for the tip. I will try to see if the parking brake handle turns tomorrow. My thought, considering how things have gone so far, is that this would be too easy.

All of the parking brake levers,that I've seen,have that adjustment cap. The cap should have criss-cross hash-marks,for a better grip. If not, you may be able to access the upper shoe adjustment by removing the trans. access cover. Depends on length of your tail-shaft. You may want to look under your truck first,to see if you can access it from above. Hope this helps.

Thank you all for help with my parking brake. I wish I had started this in a different thread, but can finish it here. There was no upper shoe adjustment - only the lower one with the large spring. I discovered that the driveline upper and lower shoes could be centered after tightening the lower nut either by use or by tapping the tightening mechanism with a hammer. And yes, there is a cable length adjustment on the handle in the cab, as described. It was just frozen like the cables and needed a good dose of penetrating oil and elbow grease to get it working. Now I just need to figure out the best balance between tight to hold the truck in place vs. loose to let it run.

I am also trying to attach a picture here in case anyone is interested in seeing what this truck looks like. So far, problems with the truck have been superficial (not internal to engine or other driveline or dump bed mechanisms). This is good since I am, so far, a superficial mechanic.

1966 GMC 5500 on return from VIN check

Well, a 5500 with Wide Fenders!! I would actually question the 5500 Emblem, but you have already supplied us with the GVW and I see that you have 6-Lug Wheels. That's a first for me, I never saw one before.

I'll try to find a picture of Narrow Fenders for you.

Bill

Here is a pretty good example of Narrow Fenders:

http://farm8.staticflickr.com/7218/7368156876_a0486c559a_c.jpg

Bill

Bill,

If I read the VIN number correctly, my 66 GMC was number 278 off the model 5500 line, so GMC might have still been figuring out what to put on it.

I had to drive the truck to the nearest California Highway Patrol office for a VIN check yesterday, which became a real test of driving skills at stop signs and traffic lights because the truck still dies at idle (more work needed on the carburetor and ignition system), the parking brake was still too loose, and all of the intersections seemed to be on hills. That done, I had to go twice to a Department of Motor Vehicles office today (using my much newer car) to get the truck registered. First, for DMV to determine that it really exists, despite my pink slip and VIN check, and then to provide pictures for an Agricultural License application. I am now the registered owner (finally) and have a temporary operating permit while the vehicle registration bureaucracy makes up its mind about the proper paperwork. The people at DMV were nice when I finally got to talk to someone, but I think this is not really finished yet.

Thanks to everyone for the help. It is probably time to put this thread to bed and start over when I have something else to ask about or report on.