420 5 speed Gear box oil advice

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CtrMint
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420 5 speed Gear box oil advice

Hi, 
I'm going to replace the (5 speed) gearbox oil while I've got the 420R in bits.  As with many things, this has resulted in a bit of a dilemma.

My owners manual says the following;

  • 5spd All models exc 160/165.    COMMA EP 75w80 GL4
  • Caterham 6spd                          COMMA EP 75w80 Mineral GL 4

That seems simple, however, with my kit, CC sent mineral as shown.  So I'm left wondering what to order?   Any recommendations, as mentioned its the Mazda 5speed.  Thanks

 

Dixa1225
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The 5 speed gearbox's normally come pre filled from CC.I have had two gearbox's recently , both were filled. Correct oil is the first one in your list or speak to Road & Race about the oil they would recommend.

MattB
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If you read the MX-5 forums (national and international) the recommendations for the Mk3 (NC) gearboxes seem to come down to Ford's MOTORCRAFT XTM5QS or Redline's equivalent.

I owned a modified NC MX5 for 14 years and never had an issue with the 6 speed gearbox, using Mobil's synthetic gearbox oil which was changed every 4 years.  The Ford oil, however, seemed to gather a reputation as a 'magic elixir' able to fix whining and recalcitrant gearboxes.

MattB

CtrMint
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Thanks for the input all.  

I found a FAQ on the Road & Race website that recommended the Redline MTL GL4 so went with that.

Caterham 420R S3 Lotus Toxic Green,  Caterham 620R S3 Exocet Red. Blog: https://www.caterham7diaries.com