Three metal door lock gearboxes laid out on a white surface, with varying amounts of visible dirt and markings.
Diagram illustrating how to measure a Mila uPVC door lock centre case gearbox, showing the "Backset" (A) and "PZ" (B) dimensions for correct fitting.
Three metal door lock gearboxes laid out on a white surface, with varying amounts of visible dirt and markings.
Diagram illustrating how to measure a Mila uPVC door lock centre case gearbox, showing the "Backset" (A) and "PZ" (B) dimensions for correct fitting.
GU

GU New Style Gearbox – Replacement Centre Case for uPVC Multipoint Door Lock – 35mm Backset 92mm PZGU New Style Gearbox - 35mm Backset - 92mm PZ

£35.99 SKU: HS3286
Backset
Lock Operation
Backset
Lock Operation
Order by 2pm for same-day dispatch
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Same-day dispatch on orders before 2pm

The gearbox is the most common part to fail on a GU multipoint lock — replace just this centre case, not the full strip, and save.Check your backset is 35mm before ordering.

Key benefits

Direct GU New Style replacement - for newer GU multipoint doors

Restores multipoint lock function - saves replacing the full strip

Standard GU dimensions - measure your case before ordering

Product overview

GU New Style Replacement Gearbox

The GU New Style centre case gearbox is the mechanism inside your uPVC door that is operated by the handle. It is the most common part to fail when a GU multipoint door lock stops working.

Replacing just the gearbox is far more cost effective than buying a complete new multipoint lock. The centre case re-attaches to your existing locking strip.

Key Measurements

The most important measurements are 28mm or 35mm Backset and 92mm PZ.

This gearbox features a reversible latch and is non-handed, fitting both left and right-handed doors.
Delivery & Returns

How much is delivery?

UK Mainland Delivery is £2.99 on all items no matter how many you order!

Northern Ireland, Scottish Highlands, Channel Islands £6.00.

We do not offer International Delivery (Ireland, France, Spain etc).

When will my order be dispatched?

Orders before 3pm (Monday to Friday) are usually dispatched same day but may take up to 24 hours.

When will I receive my item?

We ship on 2 working day courier. Fully Tracked. Tracking will be emailed on dispatch. 

Special order items such as keyed alike locks will take longer to dispatch. Please refer to product description for lead times. 

I haven't received my item?

Please email us your name, order number and date of purchase.

We prefer email as it allows us time to research and respond.

Returns Information

We operate a 30 day refunds and return policy. 

If you change your mind you must return the product back to us within 30 days of delivery

Please include a copy of your invoice and a note stating reason for return. 

Additional keys, locks keyed alike or built to code are non refundable as they are personalised made to order goods.

Any refund, which is due to a fault or other defect, will include a refund of the applicable delivery charges otherwise not. 

It is the buyers responsibility to arrange the return of goods to us. We do not offer a collection service for returning items. 

Items must be returned including original product packaging and accessories.

We reserve the right to refuse any returns that do not comply with this policy.

Please post returns to the following address:

Home Secure (Online)

Unit 5, Brookfield Drive

Liverpool, L9 7AJ

United Kingdom

Frequently Asked Questions

The GU gearbox is the central mechanism in a multipoint locking system, responsible for controlling the handle and key operation. It ensures all locking points engage securely along the door.

Common signs include a stiff or loose handle, difficulty turning the key, or the door not locking properly. These issues often indicate internal wear within the gearbox.

No, compatibility depends on factors such as backset, PZ centres, and the specific lock configuration. Always check your existing gearbox specifications before replacing it.

Yes, in many cases the centre case gearbox can be replaced on its own, making it a cost-effective way to restore your door’s functionality.

Multipoint locks secure the door at several points along the frame, improving both security and sealing. Learn more in Beginners Guide to uPVC Door Locks.