Hi folks, I’m Matt, and welcome to my father, brothers and my project, a 33' 3 ton GMC dump truck a 221 "GMC" engine and a gar wood hydraulic dump system. My father bought this years ago when he was 16 and it was together and running ( something like 1970 ), started to work on it and then got busy with life and kids and this got left in bits and pieces since then. Now he wants it back together so he can drive it before he gets too old. So here we are working on it. My father would be OK with us just putting it back together and getting it running without fixing or cleaning much, so this restoration may be quite rough around the edges in some places but there is plenty to clean and fix or else it wont go back.
The truck is in about 500 pieces right now, ripe for cleaning and putting back together. My dad bought this running in the late 60s or early 70s here in southern California from a junkyard and promptly tore it to pieces planning to restore it. Then he had my brothers and I, and well now here we are helping him put it back together after so many years.
We plan getting it back together and running so he can drive it, its not going to be show car by any means but assembled, painted and driving is our goal right now.
At some point soon I will get the other pictures I have of the truck while it was together in a gallery to look at along with some other documentation about the cab and chassis that GM sent my father in the 70s when he wrote to them for info, I haven't found a ton of info on this truck so I am some one else might find it useful.
A few pics from when my dad bought the truck when it was together, and a few as things are now in our garage here.
Some of these posts might be a bit long winded - I have not been able to find a whole lot of info on these trucks so I will try and detail things a bit more, maybe some one else will find it useful and this way I can come back and read what I did when I mess something up. Don't hesitate to ask if you have any questions or tell me when I am wrong about something
This truck is pretty big and once we get any parts back on the frame its going to get crowded so we thought the first thing we should work on are the axles to get it into a safely movable state, with brakes and steering wheel so we can get it out of the garage. Plans have changed since then a bit but axles are still first to get worked on.
So we started on the rear axle.
I don't know much about axle itself, it has a round 10 bolt rear cover with "GMC" stamped on it , the front plate ( facing the engine) has "Timken" cast on it with the numbers 5209 , might be S209, then A-183 or A-123 they are kind of hard to read. I have not been able to find a similar axle or much info on it outside the chassis maintenance manual we acquired from GM about this truck. This rear axle has the parking brake linkage attached to it between the front housing where it meets the drive shaft and the backing plate of the brake, it has a rod the linkage connects to with a threaded brake adjustment connection, one for each side.
We dropped the differential cover to find a layer of dried out oil on things, no surprise there, least it kept it from rusting. The differential seemed to be in decent condition at least, no obvious problems. tooth wear good and bearings seemed good , we cleaned it out and buttoned it back up.
Next were the drums and brakes. Both brakes seemed locked up but on closer inspection and to my surprise they were both in decent shape already. My father did not remember working on them when he first bought it, he guessed that either the previous owner or my grandfather, who was helping him at the time, must have cleaned and rebuilt them. New bearings on one or both sides, they were all in great condition if they were not new. Leather seals on the back of the rear bearing also seemed in decent to good shape, all the brake components were painted with what looked like red primer, although I know it will burn off when used but we accepted it for now and moved on. I lubed up the moving parts in the brakes with some high heat silicon grease. the pads were like new on passenger side ( same side with new bearings ) and a little worn but in spec with the manual on the drivers side. These brakes have 4 pads to them which is some thing i have not seen before, 2 for the pedal brake facing the rear and 2 for the parking brake facing the front.
The axles were removed and cleaned like everything else, however the axles are not the same on either side. Same length and size since they both fit however the bolt patterns are slightly different, one side uses a bolt and conical split washer on all the bolts that connect it to the hub, the other axle only has conical holes for 4 of the 6 bolts that attach it to the hub, so interesting difference there. Also to note the axles both had GMC TRUCK CO and LOS ANGELES CA stenciled on it in white, if not important I found it interesting at least.
With everything cleaned and lubed and greased I put the drums back on. These drums appeared to have been 2 pieces , the lug studs going through the drum to the hub and keeping it all together. The studs were welded to the threads in the drum/hub assembly, unsure if it came like that but that's what I have. The axle or hub locknut was screwed on until the drum bound and then loosened about 1/4 turn , per the manual. The lock nut is a split nut with 2 bolts to cinch the nut together locking it in. There was no seal between the axle tube and the bearing that I could find or the book showed but it seems to be a common seal on other floating axle trucks, we are likely missing them.
The old axle to hub bolts were not good, as a few broke when removing and a few were in bad shape , we replaced them but could not find the original style high head and high nuts that were used for this hub setup, we used a set of grade 8s in place of them and had to grind one side of the nut for it to fit into the hub casting, for now they will work but stand out like a sore thumb. I am trying to figure out what type of plating or finish bolts were likely to come in back then, I suppose black oxide or a zinc plate were possible but unsure as every bolt we have for this thing are rusted, it seems a lot of them will need replacing except maybe the larger bolts.
That is all for now, as soon as we get the blasting cabinet I will start work on putting the front end together. My father is working on fitting some pieces on the truck that he does not remember where they go so we have an idea of what we have or don't have.
Ive included some photos of the passenger side brake and how I found it after I don't know how many years of that hub being on it, I was surprised when I saw paint and not rust that's for sure.
