What Size Inner Tube Is On the etrailer Boat Trailer Jack
Updated 01/19/2026 | Published 08/02/2024
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Question:
Hello. Regarding the RAM brand of marine swivel jack MJ-1200, I have a few questions. They are: 1 Is the Ram jacks outer tube 2 1/8inch and the inner tube 2? 2 When you purchase the RAM brand MJ-1200B, is the 6inch poly wheel that comes with it a JC-101 or something else? 3 What is the bolt thread and size that attaches the poly wheel? Thank you in advance. Kelly S.
asked by: Kelly S
Expert Reply:
Kelly, the etrailer Boat Trailer Jack # MJ-1200B you're referring to has an outer tube diameter of 2" and an inner tube diameter of 1 3/4".
The wheel that comes with this jack is a JWK-6P # JWK-6P, and the bolt measures 3", has a 7/16" diameter thread, and the main shaft measures 1/2".
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Product Page this Question was Asked From
etrailer Boat Trailer Jack w/ Wheel - Sidewind - Swivel - 10" Lift - Zinc - 1,000 lbs
- Trailer Jack
- Boat Trailer
- Utility Trailer
- Side-Mount Jacks
- Swivel Jacks
- Sidewind Jack
- 0 - 1000 lbs
- Manual Jack
- 10 Inch Lift
- Bolt-On
- With Wheel
- etrailer
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Robin H.
1/19/2026
Hey Kelly, did the details on the tube sizes and the JWK-6P wheel match what you needed for your RAM swivel jack? Knowing how that fit worked out could help others checking their jack specs too.