Timken VS GMC Pillow Block

[Forgotten Field]

I saw on another forum that Timken axle pillow blocks could be made into GMC (Banjo) pillow blocks and vice versa. Is this true? I just acquired a pillow block attached to a GMC rear. I want to know if I should sell it or hold onto it for my Timken rear truck spares.

[Gordon_M]

Basically, yes - as far as I know.

WW2 GMC Pillow blocks come in three flavours, split axle, banjo axle, and banjo axle for DUKW.

The basic block and bearings should be the same, but you will have to swap over both end yokes to shift from split to banjo, and for the DUKW you have to swap one banjo end to the other end, and put the special DUKW flanged end on the other end.

I bought a spare pillow block for my DUKW when I had it, and it is still on the shelf, but it doesn't eat much - might have another DUKW or CCKW some day....

(No, I'm not selling it, and it is way too heavy to post anywhere at any reasonable cost, but if you are passing though central Scotland with a GMC some time and your pillow block lets go - just let me know )

[Forgotten Field]

Gordon,
You are a prince of a fellow! Thanks very much for the offer. I am hoping that my GMC does NOT have to return to Europe again, but if it does, I will be sure to stop by. I was just about to post the same information- a friend called to let me know it did fit, but had to be turned around.
This axle has a bit of personal history. In the summer of 1990, a friend of mine called to tell me there was a WWII truck at a shop and that I should go look at it. So I went up with him to the place and saw a hard cab CCKW sitting in the weeds. The guy wanted $500 for it. I wrote a check for a deposit. Well, a few weeks later, Iraq invaded Kuwait, and I had to go to work for three years. When I returned, my friend told me the old owner died and the shop closed. I wasn't going to quibble with an estate for $200, so I forgot about it.
Yesterday, I was driving by and saw the same business, still open. So I stopped by. They scrapped the truck a few years ago, but stiill had the intermediate axle with pillow block, stubs with universals on it and the drive shaft. The guy gave it to me. The axle is going to Milspec for his spares and the wheels, wheel cylinders, brake shoes and pillow block are staying in my spare pile for the new CCKW.
Thanks again- you are always helping me! I hope I can return the favor many times!

[RANGER]

Changing one end to the other is not all that simple, it involves complete disassembly, reassembly readjusting preload along with getting it sealed back up. It ain't a 5 minute job.

[Gordon_M]

Changing one end to the other is not all that simple, it involves complete disassembly, reassembly readjusting preload along with getting it sealed back up. It ain't a 5 minute job.

Absolutely right, but it is cheaper than buying one specially and as you always tell us all the details are in the manuals - you have but to read them.

[RANGER]

Heavy duty shop tools are necessary, these do not pound apart easily, and if the pillow block is used, it is likely that bearings, races and resleeving of the yokes is necessary along with new seals. Been there done that. NOS components for the Pillow Block are not allways found thru one source. Been there, done that. It ain't a "kitchen table" repair.

[Gordon_M]

Depends on your kitchen table I think ....

My unit is a US Army rebuilt with new bearings, seals, and so on, so I'd expect it to come apart and go back together quite well. I haven't read up on it, but I take it you just preload the bearings to elimanate end-to-end slop and wind-up?

The drivetrain in a DUKW is particularly stressed, and the notable failure areas are the pillow block, intermediate differential, and transfer case main bearing. The DUKW pillow block has a particularly hard life as it is under water when the unit is swimming, and standing orders are to pump the whole pillow block full of grease at every check.

[RANGER]

Ya gotta do one first, then you will know why the comments about the job.

[motto]

It's interesting that you mention the DUKW driveline components that are prone to failure Gordon. I've broken up two of these vehicles in the past and dismantled a third for rebuild. One had the pillow block shaft flopping around like a broomstick in a shirt sleeve, another had all the teeth missing off the intermediate pinion and had been run like that until the area where the teeth should have been was polished and blued and the transfer cases being run in neutral with the prop in motion does them no good either so your information seems to be quite correct.
David

[RANGER]

Drivelines on DUKWs are overworked in comparison to CCKW and tend to be neglected more due to the construction and use in water.

[Gordon_M]

The driveline is indeed stressed.

The pillow block does a lot of work, as does the transfer case input bearing, but I have noticed that every time I see a DUKW with axle problems it is ALWAYS the intermediate diff, never the front or rear.

Since the diffs are all constructed the same, I expect that the answer lies in the transfer case. All the time you are running in the water the gearbox is turning, and so is the input to the transfer case. I expect that the front and rear axle drives are somehow better supplied with oil that the output for the intermediate axle, and that the failure of the intermediate axle drive IN THE TRANSFER CASE is what takes out the intermediate diff.

We could get some way towards confirmation of that if one of our resident CCKW experts tells us that the plain, non-floating variety of CCKW doesn't have an undue tendency to blow intermediate diffs any faster than fronts or rears?

[RANGER]

Don't have a good answer, but the Inteermediate axle is the one that usually gets put under load first in difficult going. The DUKW is a lot harder on drive trains than Banjo CCKWs. Many CCKWs were converted to Crane Carriers from the immediate post war years thru the late 50's, they were extremely hard on driveline components and differentials due to the overload and the nature of the terrain they were put to work on. The CCKW running gear is most suited to use per the weights in the TM.