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OD 4.22 Differential

Discussion in 'Alpine Cars and Parts Wanted' started by cnalbers, Apr 9, 2022.

  1. cnalbers

    cnalbers Donation Time

    Anyone know where I can get a 4.22 ring gear & pinion?
     
  2. alpine_64

    alpine_64 Donation Time

    All USA spec SV had the 4.22 rear in standard transmission cars as well as OD models.

    If you have or are installing an OD into your car and have a 3.89.. Keep the 3.89...it makes a wondeful highway gear.. The series 3 alpine OD uses that as standard and its mph per 1000rpm is the best of all Alpines.

    I have 2 x OD Alpines in the family... A SIVGT with factory OD and 4.22 and a SII i fitted OD to and kept the 3.89.. The sii is much better on the highway and the 4.22 acceleration is not noticeably better than the 3.89

    Just my .02
     
  3. RootesRooter

    RootesRooter Platinum Level Sponsor

    Since it keeps coming up, just a reminder that roughly the first 12,000 non-OD Series V's came with 4.22's. The rest of the non-OD V's came with 3.89. I have two Series V's - one with each ratio. The 4.22 makes for much easier acceleration around town and is fine on the highway up to around 60 mph. Above that, the extra rpm's get buzzy and I start reflexively reaching for a 5th gear that isn't there. If you drive it on freeways trips a lot, 3.89's are the way to go, with or without OD.
     
  4. alpine_64

    alpine_64 Donation Time

    Agree with 3.89.. But i never really saw the advantage to the 4.22.. 1st gear in the alpine is so low anyway that shorter than 3.89 final drive is not needed. I drove my SII with non OD 3.89 for 10 years without OD.. It would happily spin alomg on the freeway at 62mph.. But was around 3700rpm.. It was monotonous... With the OD it was so much nicer... And as i said before once i fitted OD and kept the 3.89.. It was noticeably better on the freeway over the 4..22 OD car.. And not noticeably worse in acceleration
     
  5. volvoguys

    volvoguys Diamond Level Sponsor

    I'm curious what makes you feel you need replacement gears?
     
  6. cnalbers

    cnalbers Donation Time

    Thanks for the input. I am going to leave the 3.89 in. It seems that 4.22 ring & pinion are hen's teeth anyway.
     
  7. Barry

    Barry Platinum Level Sponsor




    I don't recall where / when / who, but a ride in a non-O.D. S-V with a 3.70:1 rear axle gearset was eye opening. 60 MPH @ about 3,400 RPM and 70 MPH @ about 4,000 RPM with factory size tires. As good as the 3.70:1 rear axle gear was with the non-O.D. transmission, I think it would be a bit too much gear for a stock 1725 with an O.D. transmission.
     
  8. husky drvr

    husky drvr Platinum Level Sponsor

    IIRC, Scott Christie's s3 ran an overdrive in front of 3.70:1 rear gears and he was definitely in favor of the combination. I also think Ian had the same set up.

    There's only a five percent difference in 3.89 and 3.70 gears.
     
  9. alpine_64

    alpine_64 Donation Time

    Not hend teeth... But in real world.. I think its a nett loss .. The cars are better with 3.89 OD or not.
     

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