What is the Purpose of the Spring Inside of a Bulldog 12K Square Jack

Updated 11/20/2025 | Published 12/15/2014

Question:

What is the purpose of the spring in the gear box. Thanks

asked by: Nick M

Helpful Expert Reply:

The spring that comes with gear set # BD500212 for Bulldog 12K jacks is a compression spring. It keeps tension on the upper gear to help keep in place and aligned. I have included a picture that shows where the inner pieces go inside the jack.

expert reply by: Michael H

click to enlarge

Kurt S.

7/27/2020

can I buy jest the compression spring for this jack?

Jon G.

8/3/2020

To get the spring that comes with the Replacement Gear Kit # BD500212 you're going to need to get the whole kit. I reached out to Bulldog who said that the spring isn't available separately.

William K.

11/20/2025

Do you know anybody that has a spring for this jack. If I have to get a gear set I might as well replace the jach cause it's more than half the price of the jack