Porsche 928 G28/55 Manual Transaxle with Half Shafts

Available for auction is a Porsche 928 G28/55 5-speed LSD transaxle with two rebuilt half shafts. The seller states this is a complete working transaxle assembly best suited for 1987 to 1991 Porsche 928 S4 and 928 GT models. The transaxle was purchased in 2006 as a fully working unit from Mark Anderson at 928 International. The unit then sat unused and was stored by the previous owner from 2006 until 2018 when the current owner purchased it and stored the assembly in a large, sealed locking toolbox with 1 gallon of desiccant moisture absorbing packs. The complete transaxle was then shipped to COGS-COGS, a Porsche transmission specialist in Cleveland, Georgia for a detailed inspection and a differential change out from the 1990 GT - PSD configuration to an S4 - LSD configuration. The final drive ratio is 2.73:1 per the 928-GT 5 speed spec. The current owner’s intentions were for the transaxle to be used as a spare backup unit if required for their 1987-928 S4 supercharged race car. The transaxle has not been used since the conversion to LSD from PSD. The original PSD components plus other spare parts including a second LSD assembly, 2 transaxle output bearing mounts, gaskets for the top cover, differential cover, and 2 complete rebuilt half-drive shafts are included. This example is serial number #01050. The transaxle will be shipped on a pallet in a securely sealed and lockable toolbox. The buyer is responsible for shipping, handling, and fees.

Auction Results

  • Buy now purchase price: $5,500
  • Auction End: 2022-06-23 21:29:43+00:00
  • Number of Offers: 1
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Comments (10)

  • Kaplan69. (registered bidder) 1 month, 2 weeksago

    I’ve always thought this is exactly what my race car needs…. No time like the present….

  • Buyer from Grandview, TX (76050) 1 month, 2 weeksago

    Purchased for $5,500

  • Kaplan69. (registered bidder) 1 month, 2 weeksago

    I was trying to bid…. I hate iPhones…. Ken

  • ROG100 1 month, 2 weeksago

    Bid in the amount of $2,500

  • JPD (seller) 1 month, 2 weeksago

    Additional content has been added to the gallery for this listing.

  • JPD (seller) 1 month, 2 weeksago

    @pinkachu Thanks for the questions. I will attempt to answer what I can and if not to your satisfaction please feel free to contact Joe, the owner at COGS-COGS. Joe did the work, and though it is unlikely he will remember specifics, he only does top notch work on Porsche transmissions.


    Regarding msmts for synchros and LSD, I do not know. My instructions to Joe were to inspect, replace anything that needed replacing and switch out the PSD for LSD. I do know he did not dis-assemble the ring and pinion to do the PSD - LSD swap so that mesh will still be as built to factory specs.

    To my knowledge no parts were replaced in the transmission, either new or used, the LSD that was swapped was a used assembly and the friction plates and discs showed little sign of wear.

    The centering spring is intact however the reverse lockout spring was removed (the flat one) as they frequently fail and end up between the gear meshes if not caught first by the magnetic plug.

    On my track car I had also removed the flat spring from the transmission and I had built a stand alone transmission cooler that used the plug at the bottom/front of the transaxle for the suction line, through an 12vdc oil pump, spin on filter and double fan cooler with the return to the ring gear cover. The last thing I wanted was that flat spring failing and getting caught up in a gear mesh or cooling pump. I will have PCAR post a photo of the cooler setup I built for those that are interested.

    Regarding the "pretty penny" comment, there are parts in this transmission that are no longer available, anywhere. This is why I wanted a backup. At this point, there is a long way to go before it sees daylight with a new owner.

    Hope that my response is helpful!

  • pinkachu 1 month, 2 weeksago

    Sounds like this transmission has a great back story and could be a worth a pretty penny. Can you provide any documentation of the work performed and a list of the replaced parts and whether any used parts were used?

    Did the mechanic that inspected the transmission gears provide the wear measurements for the synchros? Is the centering spring and reverse lockout spring still intact? Were the LSD parts replaced new or used? Do you have a wear measurement of the final LSD assembly?

  • Alec928 1 month, 2 weeksago

    Bid in the amount of $2,300

  • Jetson8859 1 month, 3 weeksago

    Bid in the amount of $750

  • JPD (seller) 1 month, 3 weeksago

    Hello all, I am a longtime PCA member. Up for auction is my backup 928 - 5 speed manual transaxle originally fitted in a 1990 928-GT. In 2018 when I went searching for a spare transaxle for my 87-928 supercharged track car I found that it was nearly impossible to find one. After extensive networking and months of searching I found this one, paid dearly for it and flat out felt lucky to get it. I had the PSD removed and replaced it with a standard 4 plate LSD that was suitable for my 87-S4. All the conversion work was completed by COGS-COGS. All the parts removed in the conversion from the PSD are included in the sale, thus this transaxle could be fitted to either and S4 or a GT if swapped back to a PSD. There are also some additional component assemblies, including 2 complete and rebuilt half shafts. I'd be pleased to answer questions. Should you wish to confirm the original serial number spec, the info can be found at website https://.928gt.com/t-928trans.aspx
    Though I had never used the transaxle, be confident that this transaxle is ready to bolt in and perform, as that was my instructions to COGS-COGS when I sent it to them for the conversion.
    For the winning bidder the tranaxle and components will be packed, locked and shipped in the heavy duty tool box as seen in the photos. I will band it to a pallet. And to make it easy and keep the freight cost down, I will deliver directly to an LTL terminal in the Detroit area of your choosing.

    Thanks for looking!

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Porsche 928 G28/55 Manual Transaxle with Half Shafts
Purchase price: $5,500
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