THANK YOU... And Need help identifying this truck
 

Hello all, and thank you very much for adding me to the list! I inherited this truck, and am having a bear of a time identifying it. The Vin # starts out V40008. So I am assuming it is a 4000 series truck. My uncle states it is a 1963 with a V6. I cannot find any engine tags on it to identify the size, so I am guessing it is the standard 305 2bbl, and my guess is model E.

It has the four speed, with a "high/low" rear end. I guess that means it has a highway setting, and a low setting?
Oddly enough, when it was stuck in mud, only the driver side tires spun, which makes me believe that is the only power wheel.

if you have any information based on the pictures, that would be great, or some way to identify the motor, I would appreciate it. also, I cannot seem to find any information on other sites about the 4000 series. Seems up to 3000, then on to 5000...

Lastly, while it isn't this forum, the truck seems to be stuck in 1st gear. I would think it would pull out, but nope. and the clutch sinks to the floor, and doesn't return. Does this sound like fluid (tranny), or a bad clutch?


Thank you again for any help.. I really do appreciate this club!

Re: THANK YOU... And Need help identifying this truck
 

*right below the left head as your are facing engine, scrape off 1/2 inch of block deck that extends out from below head, that will have your engine number. Should be a picture in 6066 GMC guy's site

Re: THANK YOU... And Need help identifying this truck
 

Jolly's site does have a registered V4008xxxxx which is a Chassis/Cab 19,500 GVW, V6 with a 305E. 1963. As stated you can find the "305E" stamped on a stickout pad in front of the passengers cylinder head. Just clean that flat pad off and read. To bad you don't have the, 1963 only, plaid valve covers. See if the clutch fork is adjusted correctly and is moving when pedal compressed. Unhook drive shaft to move it around if you need to. "Stuck in the mud"? Wheels spinning? Locked in first? Were you locked in first during this? How did you start it up? Anyway, it should say GMC 4000 right on the fender. I don't know anything about those big old trucks.

Re: THANK YOU... And Need help identifying this truck
 

Chances are, your clutch is fine. Most likely you need to replace the master cylinder which is shared by the brakes and the hydraulic clutch. If the clutch still doesn't release after you replace the master cylinder, replace the slave cylinder too. It's mounted down on the bell housing. Both parts should be readily available at a good auto parts store.

Nice looking truck! Good luck getting it roadworthy again! Keep us up to date on your progress.

Re: THANK YOU... And Need help identifying this truck
 

Welcome to 60-66 GMC. I can positively assure you both rear wheels get power. It's the nature of an open rear end to send power to the rear wheel with the LEAST traction. There's an entire industry built up making locking or torque biasing differentials. Unfortunately nothing available for an axle as big as your #4000 GMC has.

With the 305 V-6 and a 4+2 trans & axle performance loaded will be lethargic. I spent a L-O-T of time decades ago rowing through 5+2's with substantially larger engines but substantially heavier loads.

But, your truck looks in EXCELLENT shape for being 53 years old. Somebody slammed the drivers door open, shame on them! Dad had 1960 Chevy 3/4 ton pickup with similar sheet metal I may or may not have dented similar to yours.

Does your truck have a PTO operated hydraulic hoist for the box? Many did.

Re: THANK YOU... And Need help identifying this truck
 

your engine number should be right in the area I outlived in your photo.

Looking at your other engine photo I see a brake line unhooked, so I'm guessing there is no fluid in the master cylinder, so the clutch or brakes won't work.

as for ID on this truck we would need to know the letters in the middle of the vin. V4008xx1001x

Re: THANK YOU... And Need help identifying this truck
 

All,
Thank you very much for all the information. In just one week I have learned that the clutch uses the brake system to work. This would explain the two problems that I have. The clutch pedal doesn't come up, and the brakes don't work. My uncle told me (after we got it started) that the brake fluid has to be refilled every three months (sounds like a leak). Once I fill it up, and find the leak, I am hoping that it goes and stops a bit better :ahhhh:

I will have the full VIN posted here , while this statement : "Jolly's site does have a registered V4008xxxxx which is a Chassis/Cab 19,500 GVW, V6 with a 305E." sounds exciting a 19,500 GVW truck.. good grief. And I will post some more photos.

I am very excited to get working on this truck!

Can anyone tell me how the "two speeds" in the rear-end work? My uncle states it is a low and high gear.. Does the "pig" physically have two speeds/gears in it?

Re: THANK YOU... And Need help identifying this truck
 

NAPA has new master cylinders for a reasonable price. If you have a hone, you can rebuild the master yourself. Slaves are also available, as well as wheel cylinders. Sometimes it is best just to go new and replace all the parts especially if the vehicle has sat for a long time and pitting has occurred.
When I did my vehicle, which sat for about 7 years, every bit of the hydraulics, clutch, brakes and wheels cylinders, had to be rebuilt or changed for new.

Re: THANK YOU... And Need help identifying this truck
 

Welcome to the club!

About the leaky brakes/clutch, the dadgum slave cylinder goes out and leaks pretty good fairly often. Here's one at Amazon i've had in my cart for a few months haha.

https://www.amazon.com/gp/product/B0...=ATVPDKIKX0DER


I betcha if it ain't in the brakes that's where it's leaking. Take a flashlight around under there (can you stand up under there? LOL) and peek.

Re: THANK YOU... And Need help identifying this truck
 

Should be a red button about an inch in diameter clamped on the gearshift lever right under the knob. OR, I've seen buttons on the outside edge of the gearshift knob about a quarter inch by quarter inch by quarter inch.

The 2-speed axle on your truck shifts electrically. If the shift style is the red knob, down is low, out or up is high. If you have the other style, high & low positions should be marked. Accelerate the truck in gear and simultaneously depress the clutch, let off the gas pedal, and shift the 2-speed to high. If your on pavement you probably only need to use the 2-speed to split 3rd &4th gears.

To shift from high 3rd to low 4th, depress clutch and release gas pedal, shift main trans from 3rd to 4th, then shift 2-speed from Hi to Lo. Engage clutch and floor gas pedal.

For a truck able to be loaded to 20,000# I think a 351 or 401 would have been a better engine choice but the 305 will get the job done, just don't be in a big hurry.