Two more on order

Enlarge Image Image 1: Sunrise Crane Service's Terex 4792 truck-mounted crane.

Subject: Terex 4792 truck-mounted crane

Serial number: 49006011-4-73

Date in service: July 17, 2001

Hours in service: Not available

Mileage: Approximately 94,000 miles

Equipment owner: Sunrise Crane Service, Inc. Peoria, Ariz.

Dealer: Giuffre Brothers, Milwaukee, Wis.

Service area: Central Arizona

Date of review: 11/12/04

 

In 1997 when Terex procured Simon Access, one of the premier products they got in the deal was the popular RO line of truck-mounted cranes. The 4700 series included the model 4792—a full powered, fully synchronized four-section boom that delivers 101 feet of maximum tip height. Maximum lifting capacity is 47,000 pounds. Although this particular unit wasn't equipped with a jib it can accept a single 26-foot or a two-section folding 26- to 44-foot jib. The boom is designed so that the jib can be fitted on either side. Sunrise Crane Service's unit is mounted on a Peterbilt chassis and powered by an 8.4 liter Cummins engine. This unit has about 94,000 miles on it.

 

Peter and Pam Heck of Sunrise Crane Service own 10 Terex cranes, all purchased within the past four years. They are in the midst of adding an additional two 4792s to their fleet. One will have the crane mounted behind the cab while the other will be a rear-mount model. Overall, Peter Heck is very leased with the performance of their Terex units.

 

Operator's impressions

Enlarge Image Image 2: Operator controls, load chart, and LMI are well situated for easy use.

The regular operator of this crane, Gabe Hamilton, has been a crane operator for about eight years. He is pleased with the overall performance of the Terex 4792, citing much praise and few complaints. Hamilton really likes the simple-to-use anti-two block and LMI featuring fast set up features, including straight forward two-button operation with a single button scroll through the menu selection. The LMI model MG-586 is supplied by The Greer Company, Santa Ana, Calif. He also said that the large LCD numbers were easy to read even on the brightest of days. The owners of Sunrise Crane Service also like the LMI for its ability to monitor and manage rated load, hook load, boom length, and boom angle.

  

Enlarge Image Image 3: The operator and crane owners gave high praise to the Greer LMI.

Quick set up and stowing of the crane is extremely important to Sunrise Crane Service because they often schedule as many as eight jobs in a day. Dual mounts permit the control box to be positioned at either of the two operator positions, which further speeds set-up and tear down.

 

Enlarge Image Image 4: Outrigger hoses are routed to prevent excessive wear or damage.

I watched as Hamilton stowed the crane to move to the next job. This was done quickly and I was impressed with just how well the hoses are routed to prevent any damage or premature wear. In addition, on the rear-mounted out-and-down outriggers there is a simple steel flange that keeps the hoses out of harms way and guides them neatly into the proper stowed position.

 

Service issues

Sunrise reports that their Terex cranes have been dependable and what few problems they have had have been taken care of by Terex. The only major repairs have been associated with the failure of the power take off (PTO) pump motor (supplied by Italian producer Salami), the swing brake, and the Braden Winch pump motor. The only other complaint is that the housing of the original anti-two-block switch was made of plastic and prone to failure. Terex now fits all units with a more robust steel encased switch.

 

Sunrise has also replaced a lot of the string potentiometer wires that run down the outside of the boom. Peter Heck pointed out that damage is usually caused when a large roof truss or tree gets tangled up or accidentally swings into the boom. In case the LMI needs to be recalibrated it can be done so in the field in about 30 minutes.

 

Really the only thing that Sunrise wishes Terex would change is to make the optional oil cooler standard equipment.

  

Enlarge Image Image 5: Outrigger locking pins were impossible to position.

I noted that the outrigger tube lock down pins were difficult or impossible to put into the locked position. It seems that with wear the inner tube has settled so low that the outer tubes hole doesn't align properly. Wear on the boom has been minimal. All slide pads are doing their job perfectly. The boom's condition reflects that Sunrise stays on top of its maintenance program.

 

Many of the items Sunrise has experienced failures on have since been addressed by the manufacturer when boom truck production was transferred in 2003 from the old RO plant in Olathe, Kan., to the heavy crane division plant in Waverly, Iowa. Many of the problems Sunrise cited were identified by the manufacturer at that time and have since been upgraded. Other changes were made based on component availability. For example, the PTO pump has been converted to a more readily available Vickers pump and the hydraulic valve body is now supplied by HUSCO Valves. Dual hydraulic filtration is also a new feature, which dramatically increases capacity and efficiency. For added durability a more resilient baked-on paint finish is now used on the boom s and all hardware and fasteners are now plated to help keep corrosion to a minimum.