Did you know Pillow Blocks

[dr deuce]

Did you people know that the pillow/pillar block bearing assy is different between the banjo and the split axles?

Funny thing is that if you dissassemble it, and reassemble it in a different way, you have the other version! One mounts to the RH side of the mounting plate welded to the middle axle and the other mounts to the LH side of the plate. Only thing different is then the vent is facing down.

If they had drilled and tapped a plug in the bottom of the housing, you could have just swapped the plug and the vent and made the other version, BUT noooo that would be too simple, Better to have to stock two different assy's!

On my banjo cargo CCKW it says TIMKEN on the housing and was swapped.


Steve AKA Dr Deuce

[joel gopan]

And you better have good machine shop facilities, as it comes apart hard, there are parts that can be ruined using the hammer and drift method, the adjustment for preload is fussy and there are precautions that must be followed in the TM to ensure that it does not leak. Thats why I keep unused ones on hand. Timken did manufacture the Pillow Block in addition to General Motors. Timken may have also made them up for GM Banjo application, as the parts are exactly the same, except for the order they are assembled.
Joel

[dr deuce]

It was a long time ago when I did this swap and I don't recall it coming apart hard. I followed the procedures for reassy and have 45,000 + miles on it since!

Steve AKA Dr Deuce

[joel gopan]

Time to take the Dial Indicator to it.
Joel

[dr deuce]

My manual says:

"Shaft end play should be barely perceptible. Bearings must be tight withut drag yet loose enough to turn freely"

No dial indicator mentioned or what it would read if you had to use one

When I grease the truck, I use 2 three ton jacks to lift one wheel on each rear axle so there is no tension on any rear drive components and also so I can check everything for looseness; U-joints, slipjoints, flanges, and pillow block. It also helps me to rotate the driveshafts to get at all the grease fittings.

45,000+ miles on it tells me I did it right!

Steve AKA Dr Deuce

[joel gopan]

End play is an arbitrary term, the perceived end play varies with each individual, and it is a guess at best for the untrained mechanic. The following instructional quotes are taken from several WWII US Army sources.

"Adjust Bearings. Tighten adjusting nut solidly to be certain bearings are properly seated: then backnut off just far enough to permit shaft to spinn in bearings, but not enough to permit any end play.Install two nut locks with inner prong seated in keyway slot. Install lock nut and tighten securely. Check adjustment to make sure it has not been changed while installing lock nut." Blah, blah, blah

The above was from the Ordnance repair Manual TM9-1801 10 Mar 44


"Install spacer (9) and adjusting nut (8), drawing nut up tight to be sure all bearing surfaces seat, and then back off until block can be turned but will not spin on shaft. Install new lockwashers (6-7) with inner prong seated in shaft slot. Draw up lock nut securely, checking adjustment to be sure it has not changed during locking operations. Blah, blah, blah.

The above was from TM10-1563, July 1, 1942.

The 1941 Dated TM10-1501 that was written for my 1941 CCKW has the same procedure, except the word "block" used in TM10-1563, called a "cage" in in the 1941 Manual.

GMC Factory Service Bulletin No. G-99 dated 17 August 1944, that has to do with the in field change over to Chassis Grease instead of Gear Oil, instructs to "Inspect assembly for end play in shaft, rough bearings, or leakage past oil seals and make necessary repairs according tp regular procedure_ TM9-1801, 10 March 1944, page 142. (And guess what? It states "not enough to permit end play")


GMC Factory Service Bulletin Dated 11 March 1944, Line 4, Adjust Bearing "Install adjusting nut washer and adjusting nut. Tighten adjusting nut solid to be certain bearings are properly seated; then back off nut just far enough to permit shaft to spin on bearings, but not enough to permit any perceptible end play. Install two new nut locks with tongue of each seated in keyway." Blah, blah, blah. Trained Ordnance personell and good civilian mechanics for that matter are taught in the use of precision tools such as dial indicators in order to eliminate guesswork. The rebuild of the Pillow Block is Ordnance responsibility. End play in shafts using Tapered Roller bearings, will contribute to a wear pattern that results in shorter life of the components. A little preload goes a long way.
Joel

[bobc]

Over my 20 years as wrench turner I have seen many people that couldn't figure out how to tighten a spindle nut! I've never had a problem it's a "feel" thing,I'm sure there is a right and specified manner for doing it but I agree with DOC,it must have been done right if it lasted 45,00 miles.

[dr deuce]

So Joel, are you now saying "Don't follow the manual"?


Steve AKA Dr Deuce

[joel gopan]

No, by all means use your manuals, I am quoting the actual Ordnance TMs, GMC factory bulletins, and the original TM10 manuals up to 43 before the Ordnance manuals took over. The TM10 Drivers Manuals were also the "Ord" powertrain manuals in the Quartermaster days. They all instruct that the assembly procedure eliminate end play. Tapered roller bearings used in this manner are a precision application, the trucks were not assembled by blacksmiths. All CCKW Pillow blocks used the same components from 1940-1945, and were assembled with care as the excerpts from the manuals show. You can follow them to the "T", or just drop the parts in and have a sloppy truck, that choice is up to the owner. It is up to the owner if he prefers the entire truck move in one piece when the clutch is let out, and not start off with the ripple effect of a freight train. The Operators manual is intended for the driver maintenance by the Army, and not Ordnance Maintenance. Drivers Maintenance is second echelon, Ordnance Maintenance is 3rd-5th and more involved and precise. Second Echelon tools sets at the Company Motorpool level were designed to include just enough tools to do minor maintenance, tightening attaching parts, fenders, bumpers, etc, changing oil, checking levels, changing minor parts. They purposely did not contain the tools that were necessary to overhaul and adjust a pillow block. The "on vehicle" tool kit had even less tools. The WWII Military had a well laid out Maintenance program, these are HMVs, GI Maintenance procedures kind of go hand in hand with owning one of these beasts if one wishes trouble free operation. It is also realized that owners of CCKWS are not all trained mechanics and that they will repair their truck to their own skill level, which may or may not be sufficient to keep their truck operational in a trouble free manner.
If one is to perform major maintenance on his CCKW, it is an advantage to buy the ORD manuals on the engine and powertrain, a lot of questions such as the one on this topic will be answered. Bottom Line, there should be a preload on the bearings, it will prevent end play, give the unit longevity, as any end play, means sideplay when dealing with tapered roller bearings, and it contributes to early failure of seals. I have several NOS Pillow Blocks, and they all have Preload with no end play.
Joel