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  1. bill308

    bill308 Formula 3
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    May 13, 2001
    1,065
    Windsor, CT
    Full Name:
    Bill Sebestyen
    I'm looking for a 328 transaxle assembly. I also need the intermediate plate, bell housing and transfer gear system. What do you have?

    Bill
     
  2. RonClark

    RonClark Rookie

    Dec 27, 2017
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    Ronald J. Clark
    Hi Bill, I have two transaxles for sale. One is from a 308, the other from a 208 (short gearsets and lower ring and pinion). Both are in excellent condition. If this helps let me know
     
  3. bill308

    bill308 Formula 3
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    May 13, 2001
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    Windsor, CT
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    Bill Sebestyen
    Hi Ron,

    My research shows two possible gear ratio sets in the 308 world. First gear tooth ratio is either 13/42 or 13/40. Fifth gear is either 28/24 or 29/24. Your description suggests the 13/42 ratio first gear and 28/24 ratio fifth gear. The big question for me is, does a 328 mainshaft work with one of the 308 layshaft assemblies. This enables later integration with a 328 bell housing assembly and its stronger drop gear system. The other asset one gets with the 328 gear box, that may be retrofit-able to an earlier case, is a pump driven oil system and the later magnetic speedo sender.

    Where are you located Ron?

    Bill
     
  4. RonClark

    RonClark Rookie

    Dec 27, 2017
    2
    Full Name:
    Ronald J. Clark
    Hi Bill,
    I am in Denver, Colorado. It is my understanding that all 308"s through the end of the carbed cars had the same gear and final drive ratios. Not sure about the two valve injected cars. The ratios were definitely changed with the QV's and 328's. You probably understand the need to have both intermediate and primary bellhousings along with the transfer case and transfer gear sets to install a 328 gearbox to an early car. The short ratio transaxle I have is from a normally aspirated 208. Ferrari felt the need to compensate for the loss of horse power by lowering the gear and final drive ratios in those cars. For someone who is interested in bottom end acceleration, and certainly for someone who wants to "track" their car, the 208 gearbox is a perfect choice. I should ad I have been servicing and restoring Ferrari's since the early seventies and know of no one who has tried to use a 328 main shaft in an early gearbox.
     
  5. bill308

    bill308 Formula 3
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    May 13, 2001
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    Windsor, CT
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    Bill Sebestyen
    #5 bill308, Jan 14, 2019
    Last edited: Jan 14, 2019
    Hi Ron,

    My research shows the 1975 GTB used the taller 13/40 first and 27/30 fifth gears, as did the US QV's, 1982 QV and 1983 QV. I believe all the 328's also used these ratios. Reverse was 17/63 for the 1975 GTB and all pre QV's 308's. QV's used a 16/65 reverse gear set. Early 1975 GTB and 328's used a 17/63 reverse gear set. The reverse gear set requires a matched layshaft pinion and crown wheel.

    Bill
     
  6. nerofer

    nerofer F1 Veteran

    Mar 26, 2011
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    FRANCE
  7. bill308

    bill308 Formula 3
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    May 13, 2001
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    Windsor, CT
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    Bill Sebestyen
    Hi nerofer,

    I had seen that page before but forgot about it. In the chart below, I added some information and checked the calculations. Round off error was inconsistent as values were truncated, rather than rounded off properly.

    The left most boxes give gearbox ratios, the middle boxes reflect the gear box ratio multiplied by the drop gear ratio. Similarly, the right most boxes reflect the gear box ratio multiplied by the CWP ratio (without drop gear ratio).

    According to the 328 WSM, all 328 gearboxes used the same gearbox ratios.

    Two drop gear ratios were available, a base version with a 27/30 (0.900) I/O ratio and a taller geared 27/29 (0.931) USA and CH (German, Swiss, Austrian?) version.

    Three different crown wheel/ pinion ratios (CWP) were used, 63/17 (O/I ratio 3.706) for base versions, 65/16 (O/I ratio 4.063) for USA versions, and 61/17 (O/I ratio 3.588).

    Overall 5th gear ratios are, shortest to longest:

    For the USA variant of the 328: (24/29)*(29/27)*(65/16)=(0.8276)*(0.931)*(4.063)=3.611

    For the base variant of the 328: (24/29)*(30/27)*(63/17)= (0.8276)*(0.900)*(3.706)=3.408

    For the CH variant of the 328: (24/29)*(29/27)*(61/17)= (0.8276)*( 0.931)*(3.588)=3.190

    I prefer the CH variant. One can change a USA gearbox to CH specification by changing the layshaft/CW to part number 132471, which has a 61/17 tooth count for a 0.931 ratio. A good used example might save enough money to allow me to go through the rest of the box and replace all the consumables like bearings, synchros, and synchro springs.


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    Bill
     
  8. bill308

    bill308 Formula 3
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    May 13, 2001
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    Windsor, CT
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    Bill Sebestyen
    Hi Guys,

    I just wanted to wrap this up. I found a US spec drive train assembly which included an intermediate plate with sensors, a bell housing and cover with drop gears and shift linkage, and a transaxle assembly. The donor was a 1988, 328 GT, with about 25000 miles on it, from one of my most trusted suppliers.It was sold as ready to go, but given the expected increase in torque input from the new 3.4 liter engine, I need to convince myself it is indeed ready to go. A complete rebuild would be about $3000 in parts and $2000 (10 hours) in labor

    Since the new box is US spec, it has a very short (4.06) CWP ratio, which means unnecessarily high rpms at cruise. I want something closer to 3000 rpm at 80 mph, than the 4000 rpm the new drive train system will yield. US spec 328 gearing is actually shorter than in the US spec 308 box it replaces.

    Frank, at Modena Engineering, is evaluating if he can improve my overall ratio with a new quick change, drop gear system. I think it is doable and if Frank confirms it, I can forget about the purchase of a NOS Swiss spec CWP to retrofit the new box and go to a taller overall ratio by just changing the drop gear ratios, for use tailoring purposes. I’m thinking a tall gear to live with, a Swiss spec equivalent, and a US spec equivalent for track work as part of a 3 ratio system. The beauty of this system is it can be installed/changed with the engine in the car, about an hour process.

    The replacement box before shipment.
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    This is the bell housing with drop gear set and shift linkage that I'll use for engine break in. Note the outboard bearings.
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    Crate as shipped.
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    Bill
     

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