worm drive rear end cleaning

AA Ford Discussion Group relating to the repair and restoration of your AA Ford.
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birdacre
Posts: 480
Joined: October 8th, 2013, 2:37 pm
Body Type: AA express
Model Year: 1928

worm drive rear end cleaning

Post by birdacre »

i have a 28 AA that has not been on the road since 1960. rear end is full of sludge. an old man recommended running it for 10 minutes jacked up, not under a load, in high gear to heat up oil and drain it, but first add 2 qts non detergent oil for the yellow gears, to the sludge. then refill with 2 qts kerosene and run for 20 minutes in high gear and dump the kerosene, then add the proper yellow gear safe oil. does this sound good to anyone, ok for this style rear end. thank you for your input. he is a smart man, i just want a second opinion.
KimVanOrder
Posts: 753
Joined: August 11th, 2013, 4:25 pm
Body Type: 82-A Platform
Model Year: 1928
Location: Hamilton, Mich.

Re: worm drive rear end cleaning

Post by KimVanOrder »

Sounds good. I set an electric heater under mine to warm it up first. Quieter and saved some time. Fill it right up with kerosene , run it and dump. Do this several times and then fill with the correct stuff. ( and yes that stuff is thick and barely runs by itself).
KVO
Dec. '28 AA
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dhetch
Posts: 54
Joined: May 16th, 2011, 5:48 am
Body Type: Stake Body
Model Year: 1928
Location: Lakeville, MN

Re: worm drive rear end cleaning

Post by dhetch »

It is good that you are aware of the need for the proper gear lube. Just so you know, there was an article in the 2017 Double AAer on selecting the proper gear lube. It is not rocket science but many of the Model A suppliers are claiming they are providing the proper lube when there is nothing to back up this claim. If you don't have the article, reply with your email address and I will email you a copy. Right now, you can pay the same amount for 6 quarts or 5 gallons of the good stuff depending where you buy it.
If it were mine, I would use transmission or hydraulic fluid rather than kerosene. These will clean and lubricate at the same time. When you get it clean enough to see the steel parts with a bore scope, if you see any signs of rust, you may want to stop and disassemble the axle. A rusted worm gear can damage a good bronze gear quickly. It is all about protecting the bronze gear. A new replacement is now $1850, more than I can afford.
Good Luck,
Dave
birdacre
Posts: 480
Joined: October 8th, 2013, 2:37 pm
Body Type: AA express
Model Year: 1928

Re: worm drive rear end cleaning

Post by birdacre »

i do have the article. thank you. interesting point about the rust. i do not have a bore scope. any other ideas for viewing worm? other than taking apart. flashlights? mirrors? thank you, kevin
birdacre
Posts: 480
Joined: October 8th, 2013, 2:37 pm
Body Type: AA express
Model Year: 1928

Re: worm drive rear end cleaning

Post by birdacre »

hey out of curiousity, what does the worm gear go for? good to know. thank you. kevin
Stakebed
Posts: 1223
Joined: June 14th, 2007, 7:29 pm
Body Type: Grainbox
Model Year: 1929
Location: Illinois

Re: worm drive rear end cleaning

Post by Stakebed »

depends on condition and wear is what they go for - low speed is about as valuable as scrap unfortunately as noone wants to travel at 18mph top speed - the high speed can go for a decent price.

I like the ATF idea for cleaning, when you drain out the old goop (gonna be sticky, stain your hands, and stink like old robitussin) see if you can strain it thru a nylon stocking and check to see how many bronze sparkles are in it - that can give an indication as well. If you remove the fill plug a bright light shinign thru the hole you can see the condition of the teeth but the worm you gotta split it to get to it and see....
KimVanOrder
Posts: 753
Joined: August 11th, 2013, 4:25 pm
Body Type: 82-A Platform
Model Year: 1928
Location: Hamilton, Mich.

Re: worm drive rear end cleaning

Post by KimVanOrder »

The worm is OK. If not the bronze would be gone, chewed up. And if it dose chew it up in the future,,,, what did you lose? not much. Have fun.
KVO
Dec. '28 AA
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