Four post lifts safety check

[Harmon C.]

I had my second lift fail with no damage to Corvettes or me. This lift was used for storage and the top pulley where two are stacked up wore the center hole thru the bearing and before I knew I had a problem the 5/8" hole was about 7/8" causing the bolt to back out with a load bang. The grindings lay on top of the lower pulley so you see nothing on the floor. If you have a four post lift check the pulleys with the pressure released and for grindings on the lower pulley. I did not lube the bearings when I installed them but I did when they failed. I had bought extra bearings and pulleys when the last one failed with the same problem. I am thinking of having the two bad pulleys bored out and bearings installed. I think roller bearings are better than ball bearings for this type of load. The lifts are Stinger and about 6-8 years old. Lyle

[Jean C.]

Re: Four post lifts safety check

Lyle, can you estimate how many cycles were on the lift prior to failure?
Thanks and best regards,
Charlie

[Clem Z.]

Re: Four post lifts safety check

i have seen this with plain bearing lifts. were yours plain bearing(bushing)?

[Brian M.]

Re: Four post lifts safety check

What brand lift are you using?

[Harmon C.]

Re: Four post lifts safety check

I have Stinger lifts but all of this type I have helped assemble have the two pulleys on a 5/8 bolt with a spacer made out of 3/4" pipe in two places. The pulleys on mine have a bearing pressed in but the wall thickness may only be 1/16". If they wear they are thru the bearing in no time. I talked to Stinger and the 7000 pound model uses a roller bearing in the pulley. Mine are 6000 pound about 8 years old. The first one to fail was in my shop and was up and down hundreds of times so I would expect some wear. I had to rebuild the nylon slides and the pulleys on that one. The last one to fail was used for storage and I would think on an average it was up and down one time a week for 8 years but this is a guess. I am going to buy pulleys with roller or ball bearings or have my pulleys machined to accept some bearings I can buy locally.Has anyone did this? Lyle

[Craig S.]

Re: Four post lifts safety check

Lyle - it would be relatively easy with access to a metal lathe, but may not be worth the cost to take this to a local machinist vs just buying pulleys from the lift supplier. I know my original Autolifters M6 has sleeve bushings, I have lubed them a few times and seem OK so far. The current lifts from Autolifters all have ball bearing pulleys, so I am guessing Stinger will sell the pulleys too....Craig

[Harmon C.]

Re: Four post lifts safety check

Craig I will make a few calls to see what new pulleys with ball bearings installed cost. Lyle

[Patrick H.]

Re: Four post lifts safety check

Lyle,

Please post the info if you don't mind.
It might be good preventive maintenance for the rest of us to replace them too.

Patrick

[Craig S.]

Re: Four post lifts safety check

Patrick - I went out and felt the pulley bushings on my Autolifters after this post....... all felt equal and the pulleys had the same wobble I recall upon installation, but they may be somewhat more. There is perceptable play when rocked, but only enough to allow the pulley OD to rock about 1/16 inch, I am guessing the pulleys are 3.5" OD or so... Craig