One of my Favorite Conversions Solutions Revisions

We rarely have to repair rear axles and usually just clean and inspect the bearings and install new oil seals. Be it a Jaguar, Chevrolet or Alfa Romeo, it is rare that we see a ring and pinion that is damaged or bearings that are worn out. I hate to disturb the factory relationship between the ring and pinion gears so if the bearings check out ok, I keep the thing together.

Additionally, most car companies have figured out how to make the final drive robust and problem free because they are aware of the forces involved with the ring and pinion bevel gears – except for Ferrari. They used a deep groove ball bearing and sliding inner race roller bearing that cannot handle the axial loads on the pinion shaft. Other companies used tapered roller bearings that can handle a tremendous amount of this fore-and-aft thrust while spinning with ease but the Ferrari style comes apart and destroys the gears.

My solution is to replace the sliding inner race roller bearing and the deep groove ball bearing with a pair of tapered roller bearings. This photo is a 250 GT Lusso center section with the “chicklet” style limited slip differential. On some axles I’ve install tapered roller bearings to support the differential but on the later axles there isn’t much room to install this type of bearing and I have found the original ball bearing set up to be adequate. I have done this conversion to many cars that have gone many thousands of miles with no issues.

Final drive Ferrari

Final drive Ferrari

GT Ferrari 250 Axle Center section

GT Ferrari 250 Axle Center section

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1 Comment »

  1. Petri Liimatta said,

    May 27, 2010 @ 12:02 pm

    Thats very interesting! thanks for information! i am sure i learned something new about ferrari!

    Best regards from Finland!

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