Fast, efficient and cost effective E-3120 gearbox replacement from DC21. We hold new complete gearboxes in stock to enable a rapid repair of your E-3120 wind turbine.
The Endurance E-3120 wind turbine is fitted with a Siemens / Flender WD5008A gearbox, this provides the necessary speed increase from the rotor (43 rpm) to the generator (1,500 rpm).
As the turbines age we are starting to see various issues occurring.
These issues can range from leaking oil seals, bearing wear, keyways bruising, or more seriously gear failure.
The gearbox has to work hard on the E-3120, it has a nominal rating of 50kW compared to turbine outputs of 60-80kW and the braking events are harsh.
DC21 can replace your gearbox up tower without the need to remove the nacelle. If the site access is difficult, don’t worry about having to bring in a large all terrain crane, we have alternative solutions (25m tower only).
DC21 has developed the hydraulic tools to ensure that we can always remove the gearbox from the low speed shaft – we have never failed to remove a gearbox, no matter the corrosion or fretting that might have occurred in service.
We are delighted that we can now offer our customers a rapid replacement solution.
The gearbox has a torque limit of 1,250Nm on the high speed shaft, and the standard Endurance braking system has a specification of 900-1100Nm. DC21 always try to keep turbines at the lower end of this range to minimise wear and tear.
A new gearbox from Siemens has a lead time of 25 weeks. We keep new gearboxes in stock to ensure we can rapidly respond to any demand and keep turbines operating.
Within the casing of the gearbox there are three reductions pairs (gear and pinion). Experience to date is suggesting that the 2nd and 3rd reduction pairs are most vulnerable to failure of the teeth.
The low speed shaft that delivers the power from the rotor/blades is connected to the gearbox via a hollow shaft and shrink disc arrangement. Again due to the duties the turbine asks of the gearbox it is not uncommon to find the low speed shaft has spun and friction welded to the hollow shaft. The key way in the hollow shaft can also become bruised.
Our 140te hydraulic tooling means we can always push the gearbox off the low speed shaft.
After many years of experience, our advice is always to replace rather than attempting to repair the E-3120 gearbox. With a new gearbox you can be confident that the turbine will continue to operate without gearbox issues for many years.
The only repairs we would recommend on a used gearbox would be seal changes to correct minor oil leaks.
DC21 can offer a new LSS that has been designed and manufactured in the UK. The design has several key features.
DC21 can provide an alternative to replacing the bedplate by delivering a reinforced bedplate at a fraction of the cost of a new bedplate.
DC21 has partnered with Serenity Wind to create a new, exclusive E-3120 rotor hub, manufactured in the UK to boost performance, durability, and ease of maintenance.
DC21 are pleased to offer the Serenity Wind spring tube upgrade with all E-3120 and E-4660 models. These spring tubes come with a 5 year insurance backed limited warranty.
DC21 can offer a complete oil filtration retrofit for those E-3120s that did not benefit from oil filtration from new. Our kits come with the all important oil level switch system to protect the gearbox in the event of loss of oil.
DC21 have worked with Nordlock to develop the Reaction Arm Expander pin for the E-3120.
![]()
Fast, efficient and cost effective E-3120 gearbox replacement, overhaul and repair from DC21. We hold complete gearboxes & gear sets in stock to enable a rapid repair
New wind turbine braking system for the Endurance E-series that will reduce the strains placed on the turbine compared to the original braking system.
New and improved flat root blade holder upgrade for E-3120, designed for superior performance, stability, and durability.
Please feel free to contact us if you would like to know more about our highly competitive endurance wind turbine upgrade and repair services.