TRNW-2: ZF8HP45 (850RE & 845RE) P0733

[Healy Powertrain]

Replace the Actual Steel D Piston too when replacing the Molded D-Seal, otherwise you'll in for a repeat failure. Check the new piston for smoothness and sharp edges where the seal rides. Replace the drum Shell where the D-Frictions eat away the aluminium (New updated drum available now from Sonnax)As far as replacing the seal, you can do it without the tools. Make sure all is centered precisely. This thing turns at driveshaft speed!
These units are going to flood your shops, basically throw away level units ( which unit isnt these days? :o). Every possible corner is cut. But the aftermarket is catching up, right on time.



Have Fun!
Marcel Verwijmeren
Healy Powertrain
Driveline Solutions
T 06 57745407
E <info at healypowertrain.com>
W <http://www.healypowertrain.com/>


On Wednesday, February 19, 2025 at 8:09:47 pm +01:00, pat schulte via trnw2 <trnw2 at trnw.net> wrote:

> One thing to watch for as well, I have not seen anyone but the Transtec piston kits have a new D "piston" All the others I have seen did not carry it.
> 
> 
> On Wed, Feb 19, 2025 at 11:02 AM Chris and Cathy Kershaw via trnw2 <<trnw2 at trnw.net>> wrote:
> 
> > I just watched this transtec video using their tool. Looks to me like it could be done without the tool, maybe get an old piston to make a jig for drilling the rivets. We haven't seen but a few with gear ratio or other internal problems. The vb/tcms have been on intergalactic backorder everytime I check. Used units seem to cheap & plentiful. <https://youtu.be/_npBS3W3dgI>
> > 
> > 
> > On Wed, Feb 19, 2025 at 11:47 AM tucker <http://tuckertrans.com> via trnw2 <<trnw2 at trnw.net>> wrote:
> > 
> > > Group,
> > > Does anyone know what the common cause of P0733 (gear ratio error in 3rd) on the ZF845 is? Many times it is intermittent and works perfect on a test short drive but the P0733 comes back quite often. We have put in about 5-6 used and rebuilt transmission, but have not rebuilt any for this common concern. We did buy a NEW 850RE valvebody and put on one that had 60,000 miles and it did NOT correct the problem. It also seems like the 2016-2017 are the most common years to see the code. As for driving it here is what's weird, is the transmission has a bad shift from 3rd to 4th cold. It flares. Reman units from Chrysler are around 2,900, so they are almost not worth rebuilding, however now they are on backorder. I find it odd too that Jasper, Certified, and ETE have them listed as not available. So what are you guys doing, and what is the cause of the P0733.
> > > 
> > > Dan Tucker
> > > 
> > > This message was sent from the TRNW Technical Discussion Forum (trnw2). You were sent this message because you have subscribed to our mailing list. If you don't want to receive these emails from TRNW in the future, please unsubscribe here:
> > > <https://www.trnw.net/unsubscribe.php?forum=2>
> > > 
> > > TRNW Inc., 2825 Walnut Terrace, Modesto, CA 95355
> > > This message was sent from the TRNW Technical Discussion Forum (trnw2). You were sent this message because you have subscribed to our mailing list. If you don't want to receive these emails from TRNW in the future, please unsubscribe here:
> > <https://www.trnw.net/unsubscribe.php?forum=2>
> > 
> > TRNW Inc., 2825 Walnut Terrace, Modesto, CA 95355
> > 
> 
> -- 
> 
> Pat Schulte
> AAMCO Transmissions
> Temecula, Ca.
> 
> This message was sent from the TRNW Technical Discussion Forum (trnw2). You were sent this message because you have subscribed to our mailing list. If you don't want to receive these emails from TRNW in the future, please unsubscribe here:
> <https://www.trnw.net/unsubscribe.php?forum=2>
> TRNW Inc., 2825 Walnut Terrace, Modesto, CA 95355
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.trnw.net/pipermail/trnw2/attachments/20250219/a191ce10/attachment.html>