I am reassembling the Timkin rear axle on my 1950 F2. I assume the rear wheel bearings need to be packed as they are tapered roller bearings and I see no way that any rear axle lube would ever get to the inner bearing let alone the outer one. Should I use the same type wheel bearing grease that I use on the front bearings? Also, would 80W90 gear oil be correct to refill the differential?

 

The wheel bearings on your full floating rear axle are lubricated from the differential. The recommendation is to pack the bearings with grease before assembly. I don't have the specs for oil wt but 80-90 will work in Michigan. I think a slight bit heavier is the recommended, but I do not know. Be sure to use new seals.

 

Sounds good but I really don't see how the differential oil would get to the bearings especially the outer ones. Since I can tell the outer bearing seized up at one time and galled on the housing stub, I want to be sure they are well lubed. Does anyone have a maintenance schedule for a F2? I was wondering if Ford recommended cleaning and repacking the rear bearings at the same time as they recommend repacking the fronts.

 

Raytash is right on the info. There is no seal between the axle and the housing so differential lube is allowed in to the hub and trapped in the void to lube the bearings, the outer bearing would be the first to see the lube.
Here is a helpful publication
http://www.ebay.com/itm/49-52-FORD-F-SERIES-TRUCK-SHOP-MANUAL-SERVICE-REPAIR-BOOK-PICKUP-WORKSHOP-GUIDE-/221230628643?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1950%7CMake%3AFord%7CModel%3AF2&hash=item33825f7f23&vxp=mtr

 

So what you are saying is that over time, gear lube migrates to the bearings and is trapped in the hub thereby lubing the bearings. How long a time before enough is in the hub before the bearings self-destruct? Oil weight and axle speed would be critical to the migration. I am not saying you are wrong but if this is the way the unit is designed to work then the engineers responsible at Ford back then had a problem waiting to happen. Probably why they changed the design on later units to a sealed permanently lubricated bearing. Thanks for the info.

ps. I already have a shop manual. Now an owners manual for a F2 with a maintenance schedule would be helpful since the shop manual leaves much to be desired on certain subjects.

 

They do need to be packed with a good wheel bearing grease. Some oil from the axle will migrate to the bearings but, not enough to keep them properly lubed. When I installed the rear hubs on my '47 COE, I lubed the bearings liberally with gear lube on assembly. When I pulled the hubs off several years later, there was a lot of flaking on the bearing rollers and races. There also was gear oil in the hubs. After seeing that, I greased the bearings on my '49 F4 as the manual stated.
Mark
P.S. Gear oil is perfectly adequate for wheel bearings in many applications. I didn't have a shop manual when I worked on the rear hubs of my '47. My Dad had told me that, at the truck shop he worked at in the '50s, that the Mack truck rear hubs were lubed from the differential oil, they were not greased. So, we went with that on my truck. I don't know if the Mack axles are filled fuller with oil or if they have some way of directing more oil to the hubs. I just don't think that our Ford axles get enough oil to the hubs to rely on gear oil alone.

 

Full floating axle design is still the same today as it was 70 years. I've only seen sealed axle bearings on certain import SUVs. Nearly all semi float C clip axle bearings are lubricated by oil. Sealed unit bearings used on FWD/AWD vehicles are a different application.

Bearings are lubricated initially by grease and later oil runs down the axle shaft as it turns or runs down the axle tube during off camber situations. Eventually the hub is filled up, level with the axle tube.

 

Interesting. When I pulled apart my axle the bearings were greased and I can guarantee you the hubs were not filled with rear end dope. IMHO, although some gear oil will run down the axle tube it is not enough to keep the bearings sufficiently lubed. The primary source of lubrication is the grease. It works on the front end and did for years before most vehicles went to FWD. I guess that is why the seals in the rear hubs are called "grease" seals and not oil seals like the pinion seal is.

Thanks for all the interesting discussion. This is what I love about FTE!!

 

We need to see some pics on that '47. (Holding out on us...)

 

Did the rear axle have the proper level of oil in it? If it doesn't the oil won't get to the bearings.

I change these seals all the time at work and I always need a drain pan to catch the oil that comes out.

Recently SKF had a recall of their seals for the 1999-2013 GM 3/4 and 1 ton trucks so a bunch of customers have to come back to get them changed and if anyone has gone a seal on a GM axle, knows how stupid they did the outer bearing compared to Ford or Dodge.

 

Cougar; This is what my shop manual shows for wheel bearing repacking maintenance.
Thanks for keeping me curious!

 

Anyone who has seen the results of an axle hub seal blowing will have no doubts as to where the 'mess' came from. The oil will cover the inside of the brake drum and outside of the rear wheels. The mess comes from the differential. Very important the differential lubrication levels be maintained.