RT Scissor Lift Delivers on Demanding Jobs
Subject: GS-4390 gas/propane RT scissor lift, manufactured by Genie Industries,
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Image 1. Genie GS-4390 dual deck extension scissor lift.
Serial number: GS9003-41435
Date in service: 5-12-03
Hours in service: 1,032
Equipment owner: Ross Equipment Rentals, a company that owns dozens of the GS-4390 and GS-5390 models, used primarily by fire protection, HVAC, and plumbing contractors.
Service area:
Date of review: 10-31-05
As buildings grow bigger and working heights increase, so do the number of large-deck and high-capacity scissors lift produced by manufacturers like Genie, Skyjack, Haulotte and JLG. Not so long ago Skyjack owned this market — with its 9250 dual deck being a leader in developing the market for machines of this size. Today, Genie's success in this product class has been driven more by a developing market than the erosion of market share by its competitors. Even with the introduction of other competing products, all manufacturers are individually shipping more machines into this segment than in the past. I recently had a chance to review how well one of Genie's GS-4390 RT scissor lifts (Image 1) is doing its job.
Overall appearance
On a previous review of a Genie scissor lift, I noted that the decals had failed to withstand either the desert heat or the onslaught of an overzealous wash rack attendant. Whatever the case may have been, it seems to be a problem of the past. On this machine, all decals and paint have withstood the elements very nicely. Thanks in part to the E-coat paint system used by Genie and
To many users of scissor lifts, the straightness of the guardrails says a lot about a machine. If the rails look straight, then the unit looks better maintained. This unit is fitted with 1.5-inch square tube guardrails featuring .065-inch wall thickness, which is heavy enough to withstand most applications and abuse. Personally, I tend to favor round tubes for their inherent strength, however, square stock is easier to repair, and the flat edge is better suited for carrying material.
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Image 2. Big deck scissors invite placing big material on the guardrails.
Big deck high-capacity scissors are the favorites of sprinkler and pipe fitters not just because of the oversized decks but also because capacity is such a critical issue. The standard GS-4250 is rated at 1,500 pounds. The problem is that these trades like to put the heavy cast pipes used for main lines and roof drains on the guardrails. Because of this, it is nearly impossible to keep the rails from drooping. As you can see in Image 2, that's exactly what appears to have happened.
Service and maintenance issues
In early 2000, I saw the prototype of this unit. I was impressed with its robustness then and am just as impressed now, seeing how the rugged design has held up. Start with the heavy-gauge steel cabinets that are made of something a lot more robust than mere sheet metal. There are two sets of these on either side of the unit split by a ladder to the platform. As robust as the doors are on these cabinets, I can't help but wonder if they shouldn't be lockable. On one side you find the lower controls, starter battery and a Tendaire-supplied hydraulically driven generator for power to the platform. On the other side, one cabinet holds the fuel tank and the other the hydraulic reservoir. As you can see in Image 3, the decals that identify these are present but could be a little more prominent. When you open the doors (Image 4), the cap on the fuel tank is color coded red and
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Image 3. Heavy-duty cabinets hide but do not secure.
says “gas only.” But on the other side the cap on the hydraulic tank says nothing. Although there is flange to secure it with a small pad lock it would be a big help if the cap was some how identified to help prevent fueling mix-ups. My concern is not unfounded.
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Image 4. Easy to confuse fuel and hydraulic oil tanks lead to contamination.
When I was looking through the service records I discovered that on this machine, and several others of this model, this has indeed happened. Being able to lock all of these solid doors would not only secure the battery but also the nearly $100 worth of unladed fuel in that poly fuel tank.
As I scanned the machine I could only find one other item that concerned me. Refer to Image 5, and you can see a pair of hoses that look out of place. These are intended to be secured in that angled steel carrier just to their left but have broken away. Upon close inspection of the hoses, I noted that they were rubbing up against the back of the engine to the point that the steel braid exposed and starting to fray. In talking to the service department, I learned that this is not an isolated problem and needs to be monitored to prevent a failure.
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Image 5. Hydraulic hoses at the bottom of the scissor stack should be monitored.
My impressions
You can gain entry from either side of the machine. Spring loaded gates swing inward. The latches are spring loaded and made of a poly material that have and will continue to provide corrosion-free service. As you can see, the top of this unit is equipped with the optional dual-deck extensions. Image 6 notes that these extensions ride on two different sets of rollers. Rubber rollers on both sides carry an independent steel support that runs the entire length of the extension. The other roller rides on an inverted V channel and carries the lip of the deck itself.
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Image 6. Deck extensions roll out easily on dual sets of rollers.
These are big decks, one 60 inches and the other 48 inches in length, and are deployed manually with the use of a large push bar. They may be big decks, but I was very pleased to say that the effort to extend these was not big. Even after 2 1/2 years, the effort required was minimal as they rolled free and easy. The entire deck floor is comprised of an aluminum diamond plate material. This is about as good as it gets.
Image 7. Although a good performer, parts for the Ford LRG engine have proved to be elusive and expensive.
The Ford LRG-4251 engine rolls out for service and preventive maintenance. This is a nice feature and makes servicing the engine so much easier. But be prepared. It will take you a lot more effort than the decks do to roll out. Long-suffering owners have struggled to get repair parts like engine control modules. I didn't realize that getting basic items such as oil and air filters was also a problem. Really the only service issue with this machine relates to Ford and the poor job it has done supporting these engines (Image 7). If anyone knows of a good source for Ford industrial parts, please let me know and I will be happy to pass it on.
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Spring-loaded pins used to keep telescopic end rails in place were stiff, which I think had more to do with lack of use than anything else. Once released, they worked just fine and as intended. The telescopic rails are used for loading 4-foot-wide material.
Owner's impressions
The computerized service records indicate that there are only two breakdown service calls on this unit — one being when they had to go out to replace the hydraulic oil when it was contaminated with fuel; the other was to replace the boot on the joystick controller. Both were problems caused by end user customer. Other than that, the service records indicated that this unit has a perfect performance record. That's pretty amazing for an IC powered piece of construction machinery of any type. Of course a performance like this, coupled with all the features and benefits of this product, will leave a satisfied taste in even the most demanding owners mouth. Ross Equipment couldn't be happier with the product.
