rotary SP84-8 cable question

[kustomfordman]

Hello, maybe somebody can give me some advise. I am replacing cables in my rotary sp84-8 (7000lb) and thought I would be clever and get them out of another "parts" lift. Problem is that the extra cables that I have are a bit longer (about 24' 1") than the cables that I am replacing (about 23' 9"). I am told by a guy at SVI (lift parts supplier) that the cables I am trying to replace fit a rotary sp55 (lighter capacity lift than the sp84). I am sure that my rotary is an sp84 as there is a tag rivited to one of the carrages stating so.

Question: Did Rotary use different length cables in SP84 lifts. I would think cable length would be determined by post spacing? Cables are used to equilize the carrages, and I don't think they have anything to do with lifting capacity...right?

Kurt

 

[Aahz]

The Rotary part number for the equalizer cable is Rotary FJ776. Cost is $66.00 each
The cable length is 23' 3/8".

FJ7114 is a cable for an SP55 and is 23' 8 3/8".

Rotary did use two different cables, depending what version of lift (ie -1,-2,-3...-11,-12), but the FJ7114 wasn't one of them. It could be that someone replaced a cable in the past and didn't use OEM parts or replaced the parts to make it work. It's always a good idea to check the conditions of the sheaves when you replace the cables. If they aren't rolling or they have extensive wear, you will be wasting your money replacing the cable without fixing the other problems.

The cables don't have to do with "lifting capacity" but they are (supposed) to be designed to help carry the load should a cylinder fail. If the cylinder failed and the cable breaks at the same time, the car is going to come down AND one side will drop faster than the other, potentially flipping it over. Moral of the story is....USE THE RIGHT PARTS!

 

[kustomfordman]

Are you sure on the cable lenght of the FJ776? I am getting conflicting information. You say the lenght is 23' 3/8", did you mean 24' 3/8"? Anyways, I know the shorter cable fits my lift...riveted tag on the carrage says SP84-8. I also need the hardware that the cable screws into on the lower connecting points of the carrage. What is the vintage of this Rotary?

Kurt

 

[Junkman]

Usually when replacing parts, you supply the model and serial number to make sure that you get the correct parts. To use used parts on a lift to my way of thinking, is being penny wise, and dollar foolish. Ther isn't much between you and a falling lift other than the cables. Steel posts don't wear out, but cables and pulleys do. Why gamble with your life and your car to save a money? Even if you didn't get hurt, the cost of the damage to the car will far exceed the cost of new cables and pulleys..

 

[kustomfordman]

I agree 100% Junkman. However, I know the history of the cables I am trying to use. They are less than 6 months old. The cables were replaced on my "parts" lift about 6 months before a cylinder blew. My shop decided to replace it with a newer model.

I think I know why the shorter cables work and the correct cables for a SP-84 are too long. Someone at some time added an extension (turnbuckle?) and bolt that could be threaded onto the end of the shorter cable thus making a shorter cable work. My cables fit now with this added hardware removed.

Now, what would be the proper tension on the cables? Also any advice on bleeding the cylinders and sync. the carages?

Kurt