Garage Door Plunger Bumper Springs are good for helping overhead doors with horizontal tracks start closing from the full open position when controlled by a jackshaft door operator. That type of operator is generally used when the track can be partially or fully vertical above the door, where the door's full weight can pull down against the counterbalance cables, keeping tension on them and preventing the cables from unspooling.
• Overall length is 15"
• 6" travel
• Approximate compression 10lbs/in
• 12 gague bracket for 3/8" bolts
• Sold by the pair
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QUESTION: How do I know what size plunger bumper springs to purchase? by Nate F 5/24/2017
ANSWER: You only need these springs on jack shaft driven door openers so carefully raise the door until the weight of the door will no longer pull the door down. This is the point that the point or just a little bit before the plungers need to contact the door then measure the distance the door need to travel up this will tell you the size of spring plunger you need. Be careful there are a lot of variables spring tension cable routing position of cable switches . by Gary C a
ANSWER: Good evening, bumper springs are usually used on direct drive openers to offset door weight and assist with the start mode of door closing. You want a minimum of 10 lbs push weight against door when all the way open. This will be approximately 6 inches of compression on a 15 inch bumper spring. <br />The right size bumper spring will depend on mounting room available and convenience to achieve this 10 lb. Minimum compression for proper operation. I like to keep the bumper springs as short as possible to eliminate side kick under tension. I used 15 inch bumper springs on 14 x 16 foot doors which work very well. I hope this helps. by John B a
QUESTION: Hi <br />I was wondering would this product work OK on a 30ft wide 18ft tall 900LBS door w/ Jack Shaft ? <br />We're afraid it's not enough umph. by Yvette H 4/10/2015
ANSWER: In my case the track configuration required the 15' spring. When installed at the end of the track, I have a fully compressed spring when the door is closed. by Michael G a
ANSWER: the ones i put up are great . as long as the 1st panel starts down the track the cables are ok, i put up 14 x14 doors and all is ok the longer springs seem to be over kill<br />on lighter doors. by Randy S a
ANSWER: Yvette, it is not so much a question of size or weight of the door but of how much spring travel you need. The actual throw is about 4 inches once you take up the bracket and spring coils. As this is essentially a 'helper spring', it will help. I was concerned that it would not be enough travel, but it is just enough to allow my double door to open high enough that I can walk under it comfortably [I am 6ft]. Hope this helps. by ANTHONY L a