ocles_inc

The ZF 5HP-24A transmission is the one used on the C5 A6 Quattro 4.2V8 models and the D2 A8 Quattro 4.2V8 models.

If you own one and it's still driving after 100,000 miles, then we heartily recommend preemptively having the pressure regulator renewed. It's in the front lower housing/casting, easy to get to once you remove the pan (26 Torx T-27 bolts -- and yes, on the early A8, some of them are a pain to reach).

On our own cars, we do that on every still-working ZF 5HP-24A transmission we own. We ship the housing to the ZF distributor in Connecticut -- savvy and nice people -- and they renew the pressure regulator with a Sonnax overbore kit, and ship the part back to us. Without this preemptive work, the odds become ever greater that a pressure spike will slip past the pressure regulator, and the hydraulic pressure will blow out the rim of the clutch "A" drum ...




... and the transmission slips in all forward gears except 5th. The transmission control module then senses the slippage and puts the transmission in limp-home mode, as indicated by reverse video on the shift lever position indicator on the instrument cluster. At that point, the only fix is to remove and rebuild, or remove and replace, the transmission.

You can probably get the pressure regulator rebuild plus a fresh filter, gasket and fluid done for $500 or so, and that prevents the classic failure pattern that would effectively kill your transmission and cost you thousands of dollars to fix.

To prevent this crisis, you don't need us for any of that.

Where you might need us, however, is if you are reading this too late.

Your transmission has already failed and now you need a used ZF 5HP-24A transmission. On the transmissions we sell, the pressure regulator has already been renewed by the ZF distributor, so the most critical part (in our opinion) has been renewed. Also, we will by then have installed a new official filter and gasket (from ZF), and fresh fluid (from BlauParts) and given the car a few thousand miles' worth of road test. As to the clutches, etc. we don't renew them -- we don't even take the transmission apart aside from swapping out that one housing -- so you're taking a gamble on a used transmission/. Even so, it's less of a gamble due to the pressure regulator having been renewed and the transmission still being in one of our A6 or A8 cars that you are welcome to come drive, so you can see for yourself how the transmission shifts and works before you buy it.

We're aiming for the price-and-quality point part-way between the $1K-plus-shipping price for a used transmission from eBay and the $4K-plus-shipping for a fully rebuilt transmission. For $2,700 our price includes:
- The transmission with the pressure regulator, pan gasket, filter and fluid recently having been renewed.
- Delivery if you're on the West coast, and the delivery happens via our entire car plus the working transmission being driven to your mechanic for removal and then we tow our car away.
- A three-year proportional purchase-price cash refund if the transmission breaks in the typical failure-pattern way that we specifically intended to prevent: the clutch "A" drum rim blowing out. For example, if this happens after 1 1/2 years, you get a refund check for half your money back. We're pretty darn confident that it won't fail as such. :-)

If you're going to be doing a transmission replacement anyway, we recommend a rebuilt torque converter. We get ours from the ZF distributor too.

Also, in the brief window of time when the lines are not attached to anything, we recommend your mechanic clean out the transmission lines to and from the radiator, with generous use of compressed air and avoiding leaving any residue from cleaning chemicals that can contaminate the fresh transmission.

If you need any other ZF 5HP-24A used internal or external parts, we probably have them, so please ask.

https://usedtransmissionsforsale5hp24a.com