The GMC CCKW

sitting in the cab my right wheel is pretty much dead. since day one it was missing a nut, two stripped,and I broke one with my 1'' impact wrench forgetting that the right side of my truck is reverse threaded. I'm wondering if it is possible to cut or drill out the old studs and put in new ones or do I have to go looking for a new wheel assembly?

Presuming you're talking about GM Banjo axles, you can press out (or beat out with a BFH) the old studs, and have new ones pressed in. I had to do that very thing with my rear hub on my G506. Timken axles or other mfg vehicles I would suspect would be the same, but I have no personal experience with them.

retro-roco wrote:Presuming you're talking about GM Banjo axles

I forgot to say that but yes mine are the banjo axles and not the split or some other brand. Mine were also welded on the inside so I guess that would have to go too. I thought so that they could be removed but since mine are welded inside I don't have much room to get anything in there to cut the weld bead.

If your studs are welded, it is likely because there was an issue with them not staying in securely when pressed in. It may be time to consider a hub swap...

I suppose it would be possible to drill out the studs, and machine the hub. However I agree with Retro-roco. If somebody has been in there welding, I think that I would be looking for another hub.

Does your truck have the fixed or removable drums? There just happens to be a removable banjo hub currently listed on ebay.

the right side of my truck is reverse threaded

Also, the left-hand studs and nuts should be on the left side of the vehicle.

Best Regards...

mudflap wrote:I suppose it would be possible to drill out the studs, and machine the hub. However I agree with Retro-roco. If somebody has been in there welding, I think that I would be looking for another hub.

Does your truck have the fixed or removable drums? There just happens to be a removable banjo hub currently listed on ebay.

the right side of my truck is reverse threaded

Also, the left-hand studs and nuts should be on the left side of the vehicle.

Best Regards...

How would I know if the drum is removable or not?

The term removable drums means just that. If, after removing the tire and wheel, you can remove the brake drum without having to remove the hubs; then you have removable drums. If the hubs are located behind or inside of the hubs, then you have fixed drums.

FYI.. TM9-801, Section XXXV has an image that shows the difference between the two types of brake drums.



On a related note, Chapter 15 of TM9-1801, the powertrain maintenance manual, says that to remove the studs on the banjo axle, the head should be drilled off and the stud pushed out from the inside of the hub (see below). Apparently the stud is staked in around it's circumference, so just trying to push it out from the outside could damage the hole. I wonder if that's what happened in this case? Perhaps that's why they were loose - causing someone to feel the need to weld them in ?

Retro-roco, maybe the guy that welded those studs in was the same guy that worked on your rear hubs.



Best Regards...

That clears alot up! I just have regular drums so I had to pull everything out and I don't think it was needed but I loosened my brakes a bit too. I also need to see if I even have that part in my service manual because I never saw those pages before but right now I have the transmission out to put in a new clutch to see if it will solve my doesn't go problem from a while back. I have an odd feeling you guys are right though and while I wanted to avoid having to get a new drum I might just have to. Is it this one? http://www.ebay.com/itm/180962338814?ss ... 1438.l2649 This guy also has the half shafts to restore my truck to a 6x6 but $400 a side is quite a bit!

Thats a demountable drum. Note the hub is attached to the back, and the drum is secured with several large screws from the front.

is that the one you were talking about mudflap? I have had my eye on that one for along time but mainly because the guy has the front halfshafts that my truck needs.

Yes. That is the one I saw.

Personally, I like the removable drum design better, since it is easier to pull off when you need to inspect/service the brakes.

Best Regards...

I would like to know now would the demountable drum work with my truck being set up for standard drums or would I have to change it all to accommodate that special one and where can I find the nuts and studs just in case?

The demountable hub and drum is interchangeable with your current hub and drum. Alternatively, I believe you can use the "new" hub and your existing drum. Check with Sam Winer motors for the studs and nuts. The studs are different for each type of drum.

Well now I have a new one. My dad will not buy me a new drum/hub and told me since the studs were welded in why not remove them and weld in New ones? and while I'll never admit to him why cant I just do that? I think a massive part of it is that my dad and I are working on the tranny and he just dropped $500 on a new clutch and throwout bearing and wants to get the flywheel machined next but I sliced my finger open so I have to Sit for two weeks before I can do anything and so far 3 days is killing me!

Call me paranoid, but I would be very concerned about driving around in a 9,000 lb. truck with a hub and studs that have been welded on.

Can't say for sure about the hub, but I would be willing to bet a shiny new nickel that those studs are made of heat treated steel, whose metalurgy is not likely to improve after being welded on.

And, even if the hub did not require heat treat during manufacture, I would still be concerned about any stresses which may have been introduced due to welding - which could lead to cracks later on.

But that's just me...

Best Regards...

Relaying for my dad but would it be possible to cut out the old studs and press new ones in and press in those serrated things holding the studs too? also I don't trust my welding since MIG welding seems too easy and my dad has faith in me but I don't and in this case I especially don't!

The serrations are actually formed into the OD of the stud shoulder. This link shows what a new stud looks like. This is not from a CCKW, but the idea is the same.

http://www.autozone.com/autozone/access ... 23746_0_0_

When the hub is manufactured, the ID of the hole is smooth, and machined to a diameter that is approximately the same as the OD of the stud shoulder. When the stud is pressed into the hub, the serrations on it cut into the ID of the hole, and help lock the stud into place - keeping it from turning when the lugnuts are tightened or removed.

It appears that GMC felt that this interference fit alone was not enough to reliably hold the stud into place, so they took the extra step of "upsetting" the stud shoulder (see diagram - previous post).

It sounds like when the studs were previously replaced, they were just pressed out from the outside, as opposed to drilling off the heads and pressing them out from the inside as the TM specifies. The "upset" on the stud shoulder reamed out the hole to the point where the serrations on the new studs have little or no metal left to grab on to.

I would not weld on the studs, as I would be VERY concerned that the heat applied to them during the welding process would weaken them. Having a front wheel come off while driving would be extremely dangerous - not only for your truck, but for anyone unlucky enough to be in the path of the run-away wheel.

Best Regards...

I would concur... The best you can do is carefully remove your welded on studs, and examine the condition of the holes in the hub. It is conceivable that your hubs could be repaired, but I think it is highly unlikely. There are parts trucks out there... A truck could be a LONG way gone, and still have useable hubs.

I took part in a long range trip for ex military vehicles here in Australia a few years back. There were two CCKWs along and one fellow during his rebuild had inadvertently transposed the front hubs so as the l/h hub had the r/h studs and the r/h hub had the l/h studs. He found that the wheel nuts kept coming loose particularly on the rough roads and you would see him going around them with a wrench every time we stopped for a break. There must be something in the l/h-r/h stud business.
I wonder if the fact they were on the wrong side was the origins of your stud problems 6x6 dinosaur?
IMHO, I think you had best replace the hub and if the hub with the r/h studs is on the l/h side of the vehicle, put it back where it belongs.

David