Differential AssemblyReconditioned exchange - Price includes refundable surcharge
Ratio 3.89:1 - correct original factory fitment for Spitfire Mk4
Sold on a reconditioned exchange basis - when you return your old unit to us within 30 days of receipt of the reconditioned unit we will refund you £200 (+ Vat if applicable). For refund your old unit must have a serviceable crownwheel & pinion (no sheared teeth) and uncracked case...the condition of other parts is not important as they are replaced during the rebuild but we need to re-use the crownwheel/pinion and casing. More details on the surcharge principle here.
Our diffs are pre-fitted with new rear eye bushes as these can be troublesome to fit without a press.
Fill with EP80/90 oil on fitting and drain & replace the oil after the first 100 miles (and then every 10000). Be sure to use an additive-free classic oil designed for the purpose - just straight oil make double sure it doesn't have any anti-foaming additive designed for front wheel drive gearboxes.
We are often asked to supply a lower ratio diff such as that from a later Spitfire/GT6/Vitesse for customers wishing to reduce the engine rpm at motorway speeds (at a sacrifice of acceleration). It is possible to fit these later diffs to earlier Spitfires & Heralds. However as it is a better and stronger diff design the halfshaft & propshaft mating flanges will also have to be changed as the input and output shafts of later diffs are also of different bigger size.
Tip: How To Tell Ratio Fitted In Your Diff