That is an older Atwood 2,500# tongue jack. I have the 3,500# model.
Yours does not look like it has the manual crank feature.
On mine, which is a ball screw unit, the manual crank would inserts in the front of the jack just below the up and down and light switches as shown on your jack. There is a removable hand crank that has a slot in a female coupling that slides on over 2 round rods in a manual crank shaft of the jack head. Inside the jack head directly the motor drive and on the ball screw shaft, it has bevel gears to allow the manual jack crank to turn the ball screw or the 12 volt motor. This manual crack feature is totally separate from the motor pack.
I do not see anything that looks like that for a manual crank below your silver motor drive.
Some may not have had the manual crank feature on the older models. Yours looks older by the switches. The newer ones, like at least from year 2005 and forward have rocker switches and not the older toggle switches.
I had an older HK engineering jack made by Barker that also had no hand crank feature. The hand crank may be a relatively new feature in the last 8 to 10 years or so.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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