Worm Drive - Worm Thrust Bearing Lubrication?

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Neil Wilson
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Joined: February 5th, 2003, 9:42 pm
Body Type: 82-A/89-A
Model Year: 1930
Location: Boulder, CO

Worm Drive - Worm Thrust Bearing Lubrication?

Post by Neil Wilson » September 12th, 2018, 7:17 am

For the worm drive axle, there was a rear axle housing cap (AA-4190) which had a fitting to allow lubrication of the worm thrust bearing (AA-4696). The cap's initial design had a pipe plug fitting as shown in the attached photo. It was the same as TT-1004. It was used to lubricate the worm thrust bearing.

So, the question is, what lubricant was used? If axle housing lubricant was used, it seems the lubricant would drain down to the axle housing. If chassis grease was used, then how was it applied?

Note that the rear axle housing cap fitting was changed to have a grease fitting about mid 1928. So, chassis grease would have been used at that point.

Anyone have information?
AA-4190-rahc-d1-b.jpg (897.33 KiB) Viewed 1049 times
Regards, Neil Wilson
neil@aafords.com - use this email for contact
https://aafords.com/ - Ford Model AA Truck Club @ aafords.com

Posts: 219
Joined: February 26th, 2007, 6:20 am
Model Year: 1930

Re: Worm Drive - Worm Thrust Bearing Lubrication?

Post by Hayslip » September 13th, 2018, 5:50 pm

Since the AA worm drive axle is a continuation of the TT version a look at page 12 of the April 15, 1919 Ford Service Bulletins is advised. The article is entitled " Lubricating the truck differential". No mention of the housing cap. The Service Bulletins of Sept. 1929 page 375 lists the capacity only. The May 25, 1928 Indianapolis letter "Rear axle grease retainer assy... is worth a read. My own feeling is that the 600 wt lube is used in the housing and some in the cap too when rebuilding an axle. Part AA4191A rear axle housing cap gasket suggests 600 wt lube instead of grease. The grease fitting replacing the plug maybe a vent since there were no check balls in the fittings in that era. Ed Hayslip

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