Spindle nut with oil seal cryptic post....

[pfarber]

The Auto Zone is about 15 miles away... I figured that they would be just about the same price all over. And they were about $2 more at Advance, but after I looked at the receipt I could have gotten another seal if I would have gotten off my lazy butt and drove the extra distance.

$2 x 4 = $8 + $6 = $14 a seal was only $19.99 as Auto Zone.

Advance said they would match the price, but I would have to go home, print the page, bring it back.

My lazyness cost me. Advance still sucks because they have ALWAYS said they will call when the parts come in. they have never called.. EVER. When they tell me they will call when I pre-pay I flat out tell them stop lying they never, ever call you.

[motto]

Just for the record and to give a little perspective on the subject . The civilian 4x2 1-1/2 ton Chev from 42 to 46 (which were also used by the military. Model numbers 4403,4408 and 4409 to name a few) used an identical wheel bearing arrangement to the CCKW Banjo and G506, BUT WITHOUT THE AXLE SEAL. TM 10-1339 shows this clearly and is in line with my experience of these trucks.

The difference is only in the intended usage of the vehicle. The 4x2 truck was intended for on road usage whereas the 4x4 and 6x6 had off road capability in mind.

What I am getting at is that if you don't intend to do any off roading, these seals perform no function and are quite redundant. Even up and down on steep grades is not a problem if they are not there. They only come into play on a significant side slope AND TENS OF THOUSANDS OF TRUCKS WERE BUILT WITHOUT THEM.

I have an 80 year old friend that has spent his life around these trucks and he is of the opinion that a bit of diff oil in the wheel bearings makes them last much longer anyway. The vital part is to make sure your wheel bearing seals are in good shape.

David

[pfarber]

The M35A2 has a similar seal (neoprene, not leather) on the outer portion of the spindle shaft. It was a horrible design. The seal worked fine, but there was a keyway machined into the shaft and you were supposed to use a small piece of cork to seal it....most guys would RTV it.

I agree that on normal roads the chance of a significant amount of oil getting down the axle tube and into the bearings is small. To much oil and it will leak onto the drums/tires... the hub seals are 'backwards' and will happily let oil by. Now you have a ruined tire (oil can soften the sidewall of a tire) and wet brakes.

I plan to take my truck into the woods (the best swimming holes are off the beaten path) and will reinstall them.

[motto]

[quote="pfarber"... the hub seals are 'backwards' and will happily let oil by. [/quote]??

You've lost me there Paul. The only wheel bearing seals I've ever seen have been constructed, located and oriented to keep lubricants inside the hub. Splash cups and slingers are also installed to prevent brake contamination in event of seal leakage. If you see oil stains on the backing plate or tyre then the wheel bearing seal has failed.

David

[pfarber]

Yes... you are correct.

If you omit the outer leather seal on the rear axle, any oil that migrates out will have a direct route to the wheel bearing grease and wash it out. The inner seal has the seal lip on the 'wrong side' and oil can easily make it past, further diluting the grease.

I think we're saying the same thing... but you note that oil in the grease is 'good' while I will maintain that its bad. I have 2 rear axles with the shafts and seals out.. and oil will easily migrate out. I can post pics of the hubs showing much more than seepage. One truck has not moved significantly in 9 months yet oil has migrated out of the axle tube.

[motto]

[quote="pfarber"] The inner seal has the seal lip on the 'wrong side' and oil can easily make it past, further diluting the grease..[/quote]

I am really trying to understand what you're saying here. Which seal are you referring to as being the 'inner seal'? Do you mean the wheel bearing seal? If so the seal lip is facing the right way to prevent lubricants escaping from the hub and it can't be otherwise for that is exactly what the seal is there to do.

David

[pfarber]

Please keep this on topic... if you want to open another thread about seal design, then please do so in the off topic forum. So unless your next post specifically addresses the leather outer seal in the banjo axle I won't allow it.

[pfarber]

I'm going to have to officially say that you need the seal.. no matter what other trucks had/didn't have it.

Seems that the November 1943 issue of Army Motors proves my point:

amseal.jpg (90.87 KiB) Viewed 12458 times

Before anyone say's I'm hiding something the original page is included for download.. I just wanted the image to show the article and images.

I'm also not saying that the seal is the EXACT SAME PART as the ones used in the G506/G508 but it disproves the statements that NOT having a seal presents 'no real problem'. I'm sure on flat level ground its not an issue. But where i live flat level ground is hard to come by. If you live in the midwest or Florida this will not be an issue. But it was a big enough deal for IHC and the Army to put out a FSMWO to correct it.

[retro-roco]

Paul,
Any luck with replacing seals on the spindle nuts you have? Would be interested in a detailed step by step...

[pfarber]

The two I have off the first parts truck were tried, and I learned a lot.

First, the nut and the castellations (used to bend the spider tabs over) MUST BE IN NEAR PERFECT CONDITION. If a previous owner used a screwdriver to tighten the nut and damaged the nut (by making burs or deforming the the channel in any way) its junk. Mine were so far gone that even filing or grinding the damaged material just made things worse.

After I got the TB from the National Archives and learned that you need a fixture, not a vice, I pretty much stopped. I did try to pry the inner seal out, but the leather ripped. The TB says use a chisel but I Have yet to locate a chisel small enough to fit the inner seal grove.

I do plan on putting the two so far destroyed nuts in my lath and cutting off the damaged part just to see how the inner channel is laid out.... maybe by then I'll find a chisel that fits.

I am wrapping up my 235 motor build this week (come hell or high water!) so axles on the Chevvy are next.