Eight Nine DiffWeld Differential Locking Fluid 500ml

£16.28 inc. VAT

Out of stock

Want a locked differential but don’t know anyone who owns a welder? Secure your place as the local streeto hero overnight with Eight Nine’s proprietary water-based non-Newtonian differential locking formula. DiffWeld works by coating the rotating parts within the differential, acting as a temporary adhesive that actively locks the differential under load.

By premixing DiffWeld with your gear oil in different ratios, the effective ramp angle can be modified to affect the locking characteristics of the differential. Mixing in a 3:1 gear oil to DiffWeld ratio results in a 45/90 ramp angle, which acts like a 1-way locking differential and is perfect for fast road cars. 2:1 gives a 45/65 1.5 way locking action, making it ideal for race cars. For drift cars DiffWeld should be mixed in a 1:1 ratio, resulting in a full-fat 45/45 2-way differential.

NOTE: Highly Limited Quantities Avaliable


  1. Remove all previous oil, using brake cleaner to ensure well flushed (removing the diff housing completely is preferred)
  2. Premix Eight Nine DiffWeld with the gear oil of your choice
  3. Carry out 10 minutes of 30 mph speeds to bring the temperature of the differential up, gently.
  4. Once up to temperature, perform 8-12 sharp figure of eights, ensuring full steering lock is achieved. *DO NOT DRIFT DURING THIS PROCESS*
  5. Once the figure of eights are complete, carry out a further 5-minute drive, this time at up to 60mph.
  6. Park the car, and let it fully cool down and cure. the non-Newtonian fluid will now be ‘set’ in place.
  7. Complete!


  • Proprietary water-based non-Newtonian differential locking formula
  • Ecologically safe and 100% biodegradable
  • Variable locking formula
  • Typical working time of 2,000 to 6,000 miles depending on use and ratio
  • 500ml size

Date Published; 01/04/2023

Additional information


Eight Nine


Mk1 (89-98), Mk2 (98-05), Mk3 (05-15), Mk4 (15-24)

Warranty information

Warranties cover defects in materials and workmanship only. Warranty is for replacement of a similar product, repair of the original product or refund of the purchase value only and excludes all labour and incurred charges including towing, fitting, inconvenience, and purchases of other manufacturer's products. The warranty is good for the period stated in the additional info tab from the date of purchase. Mileage warranties are for road use only and proof of mileage is required. Products must be installed by an independent experienced professional mechanic and the suspected defect must be present at the outset. The warranty does not cover damage caused by incorrect installation, failure to comply with the maintenance requirements of the vehicle, processing or otherwise changing the product, ordinary wear and tear, or any other external influences. Warranties are invalid if the product is used for racing, rallying, drifting, track days or any other form of motorsport or competition. Please refer to the manufacturer's own warranty documentation for more information.

Making a warranty claim

Proof of purchase receipt showing the date of purchase, proof of mileage at installation, proof of current mileage and invoice of the work undertaken by an independent experienced professional mechanic must be supplied along with the returned products for a warranty claim to be considered. If your vehicle needs to be used whilst your warranty claim is considered replacement parts from the same manufacturer should be purchased through BOFI Racing. In the event of a successful warranty claim, we will refund the card that was originally used to purchase the replacement parts, in full or in part depending on the nature of the claim. BOFI Racing reserves the right to make full or partial compensation at its sole discretion depending on the condition and mileage use of the returned suspect parts. For example, if you have used the part for several thousand miles before a defect is noticed, only partial compensation may be offered.

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