T25,G1,G2 Alternator Belt (625x10) - 1.6 (EW), 1.8 (DX,2H,EX,JH), 1.6D (CS,JX), 1.7D (KY)

This 9.5 x 630 mm alternator V-belt is a durable, correctly sized drive belt used to power key engine accessories—most commonly the alternator (charging system) and, depending on model and pulley layout, additional ancillaries such as an auxiliary pump or air conditioning compressor setups on certain applications.

The belt runs between the crank pulley and the alternator pulley. As the engine turns, the belt drives the alternator to generate electrical current, keeping the battery charged and powering ignition, lights, heaters, cooling fans, and all onboard electrics. A belt that is the correct width and length is essential to prevent squeal, slippage, poor charging, or premature wear of pulleys and bearings.

This belt is particularly useful on Mk2 Golf models—including 16v and air conditioning variants from specific chassis numbers—and also suits Corrado models without air conditioning. It is additionally listed for T25 (T3) models equipped with an additional pump or air conditioning, where belt routing and accessory load demand reliable grip and stable tension.

If your belt is cracked, glazed, noisy, or stretched (often seen as low alternator output or intermittent charging light flicker), replacing it is a simple, cost-effective way to restore dependable charging and reduce the risk of breakdown.

What this belt does

• Drives the alternator to keep the electrical system charged

• Maintains consistent grip under load (lights, heaters, fans, etc.)

• Prevents belt squeal and slip when correctly tensioned

• Supports accessory drive on certain A/C or auxiliary pump applications

How it works

A V-belt wedges into the pulley grooves. As engine speed changes, the belt transfers rotation from the crankshaft pulley to the alternator pulley. Correct belt width (9.5 mm) ensures the belt sits at the proper depth in the pulley for maximum contact area and reliable drive.

Fitting notes & recommended associated parts

• Check pulley condition: rust, sharp edges, or misalignment will destroy belts

• Inspect alternator bearings and brackets for play

• Set correct belt tension (too tight damages bearings; too loose causes squeal/slip)

• If fitting on an A/C or auxiliary pump setup, confirm pulley arrangement matches your vehicle

• It’s wise to carry a spare belt in classic vehicles used for touring

Specification

• Belt Type: V-belt (alternator/auxiliary drive)

• Size: 9.5 x 630 mm

• Width: 10 mm

• Length: 625 mm

Note: Belt sizing is often expressed differently depending on measuring method (outside length vs effective length). This listing is commonly referenced as 9.5 x 630 mm, with equivalent catalogue dimensions shown as 10 mm width / 625 mm length.

Fitment Notes (as provided)

VW Golf Mk2 (1984–1992)

• Standard models

• 1990–1992 with air conditioning from chassis 1G-MW240 001>>

• 16v models with power steering from chassis 1G-MW240 001>>

• 16v alternator belt with air conditioning

VW Corrado

• Models without air conditioning

VW T25 / T3 (Transporter)

• Models equipped with an additional pump or air conditioning