JCB & Excavator Cabin Glass Replacement: Curved vs Flat, and How to Order

By ECI Glass · 11 November 2026 · 5 min read

A broken cabin glass stops a machine. The fastest way to get it back to work is to order the right glass the first time: the right shape, the right type and the right holes. This guide explains how to tell curved glass from flat glass, which glass type your cabin uses, and exactly what to send a supplier for an accurate quote.

Which glass does a construction machine cabin have?

Most backhoe loader and excavator cabins have four to six glass panels:

• Front glass (windscreen): the largest panel, either laminated or toughened depending on the machine.
• Door glass: often split into an upper and a lower panel, usually toughened, with holes for hinges, handles and locks.
• Side glass: fixed or sliding side windows, usually toughened.
• Rear glass (back glass): toughened, sometimes with holes for a wiper or a latch.
• Roof glass: on some excavators and loaders, for a view of the bucket or boom.

Curved or flat: how to tell

Lay a straight ruler or a long spirit level across the glass, edge to edge. If the ruler touches the glass all the way along, the panel is flat. If there is a gap in the middle or at the ends, it is curved.

It matters because the two are made differently:

• Flat glass is cut to the outline of the original panel and edged. It is quicker to make.
• Curved glass is heated and bent over a mould made to the original curvature, then toughened or laminated. A curved panel that does not match the cabin frame exactly will not seal against the rubber, can leak, and is put under stress that can crack it later.

For curved glass, the best reference is the old glass itself, even if it is broken, or the machine's part number. A good manufacturer will match the curvature from the part number, a drawing or a sample.

Laminated or toughened: replace like with like

• Toughened (tempered) glass is heat-treated. When it breaks, it shatters into small, blunt pieces. Door, side and rear glass are usually toughened.
• Laminated glass is two layers of glass with a plastic interlayer between them. When it breaks, it cracks but stays in one piece. Some front glasses are laminated.

Always order the same type the machine came with. A stamp in one corner of the glass usually shows the type and the maker's marking. Take a photo of it before you remove the broken glass.

Holes and cut-outs must be right before the glass is made

Toughened glass cannot be drilled or cut after it is toughened; it will shatter. Door and rear glass with holes for hinges, handles, locks or wipers must be made with the holes already in place. When you order, send a photo of the whole panel with the holes visible, or the old glass as a sample.

What to send for an accurate quote

1. Machine make, model and year, for example "JCB 3DX, 2019" or "Tata Hitachi EX 200".
2. Which glass you need: front, upper door, lower door, side, rear or roof.
3. The part number if you have it, from the parts book or the dealer.
4. A photo of the whole glass and a close photo of the corner stamp.
5. For a flat panel without a part number: width, height and the shape of each corner.
6. For a curved panel without a part number: the old glass, even broken, or a drawing.
7. Quantity, and the delivery town.

Fitting tips

• Clean the frame and check the rubber seal. A hard or cracked rubber is the most common cause of leaks and repeat breakage, so replace it with the glass.
• Check that the door closes without forcing. A door glass that is pushed into a twisted frame will crack.
• Keep the protective packing on until the glass is at the machine. Most edge damage happens in handling, not in fitting.

ECI Glass makes cabin glass for construction machines

ECI Glass is a direct OEM supplier of construction equipment glass to Caterpillar, Doosan Bobcat, SIAC-SKH and Manitou. The same plant, tooling and quality checks make aftermarket front, door, side and rear glass for JCB, Tata Hitachi, Mahindra, L&T, CNH, SANY, ACE, Escorts and practically every machine brand sold in India.

Our glass is made under ISI (IS 2553 Part 2), ECE R43 (E11) and ICAT (AIS-037) approvals, in a TÜV SÜD ISO 9001:2015 certified plant at Kala Amb, Himachal Pradesh. Hard-to-find parts can be made from a drawing, photo or the broken glass in our in-house tool room. See all construction equipment glass.