Lift Locks Not Working Properly

[bmarshall1]

I have an older Ben Pearson LAS7, once the lift is raised off the locks, each side has a 'L' shaped lever that get pulled to release the locks. As long as the lift is lowered (with the lever pulled) the latch/locks stay unlocked, but if I were to raise the lift, something causes the latches to re-engage so they can lock again on the next hole. I am thinking maybe something to do with the tension of the lift chain?

Anyway, one side works perfectly but the other side will not hold itself 'open', or in the unlatched position. in other words, I pull the lever but it is spring loaded and goes right back into the lock position. It almost like the proper working side 'cams over' into a position that the bad side does not. I can keep it in the unlock position by wedging the lever open, but this is not the best way.

I have looked inside the posts many times (it's difficult) and can not figure out the internal mechanism nor why the one does not work. Any thoughts?

 

[Chevy-SS]

I use a Challenger 4-poster in my garage and had similar issue. The locking mechanism needed adjustment. I only noticed it after I was letting my truck down and one of the corner locks didn't disengage, which caused the whole lift to get cockeyed. For those few seconds I had happened to turn away and by the time I looked back, the truck was ready to fall off the lift!!!!!!!!!!!!

I got lucky and managed to re-raise the vehicle and the get the lock disengaged. Once I got the truck safely down and off the lift, the VERY next thing I did was to tear into that locking mechanism and fix/adjust it. It was a little counter-intuitive, so it took me a few minutes to figure it out. I have a feeling you are going through same process as me. So just get in there and figure it out, these things are relatively simple, but confusing at times. One thing for sure, it's gotta be fixed. Fix it and adjust it so that it's PERFECT!

Good luck.

 

[3rdgendslmech]

Def take a look at the lock mechanisms. The guy I do side work for has a 2 post with single point locks. Once you release the locks and it's lowered down they're supposed to reset to catch on the locks the next trip up. Well one post as the lift is going up you have to flip what looks like a cam inside the tube. From what I can tell by looking through a 1" hole there's either a spring out of place or a cable that needs to be adjusted.
Just an idea of what you might want to look for too.

 

[sberry]

They get dirty too, spray them with pen spray. Some are really finely tuned and use gravity and the latch needs to swing free.

 

[pugsl]

Please don't put a car on lift till fixed. Have worked in an shop where we needed all lifts and if you have never seen a car fall it ain't pretty. We had a lift in ground that had a small oil leak and before could be fixed Had a jack under back 7 foot jack stand under front for something and mechanic stepped away to do something and when he turned around front was all the way up and back almost on ground. Caught it in time but was scary. We quit jamming lift lock after that. Common practice in 70 & 80's

 

[bmarshall1]

Thanks All. If you see my other post about the leaking cylinders, I have to pull them out so the lift will be in-op until they are fixed. Once the cylinders are out I will dig into the latch mechanism, I was hoping someone would be able to pinpoint the exact issue, but Internet Diagnosis can be difficult =). I had assumed a spring or something out of place and will have better access once the cylinders are out. FYI - I also use 2 heavy duty hi-rise (6 foot) jackstands to stabilize once on the lift. The car absolutely does not wiggle one in the air.

 

[aarcuda]

Did you ever resolve this? I have the same lift and a similar but different problem. Both my release levers lock open for lowering but I need to manually reset one lever to get it to reengage for the next lift. The other lock automatically reengages.

What ive found is the grease was preventing the lock assembly to “fall” back in place as the carriages rise. Its too much of a job to remove the carriage to fix it so I manually reset it and just live with it.

But in your case, your lock won’t stay released so you can lower it and that’s probably because there’s an offset cam in that locking mechanism that needs to roll upwards as you pull the lever. It rolls upward to the point that it falls over the top and will remain there until you go to lift it again and then the cam hits the back of the post and reengageS. If that cam doesn’t roll over the top, it will just fall back down and reengage.

Since it’s almost impossible to do anything to that locking mechanism with the carriages inside the post, it’ll be hard to fix it without removing the carriage. But if you do get the carriage out, just remove all the old grease. Make sure everything is decreased and is free to move and that they can move to the position that needs to move to hell to stay in the unlocked position.

 

[aarcuda]

Heres a breakdown of the carriage parts