TRNW-2: 6L90, jmdz torque converter

[Justin Merritt]

We have seen a few of these converters. They don’t seem to go down as bad as a jmbx. Talk to your supplier about core before deciding to use a billet jmbx in its place. We just use a reman jmdz when we see it. 

Justin 
Sent from my iPhone

> On Oct 29, 2025, at 5:35 AM, Fred Whitaker via trnw2 <trnw2 at trnw.net> wrote:
> 
> 
>   Not sure I have seen a JMDZ converter. But If I were overhauling it,there is no way I would use it over. ANY Transmission I overhaul with 140K would get a new converter. Captive clutch or not. I would simply replace it with a quality converter from a supplier you are comfortable with. I myself wouldn't mess with the programming. The first one went 140K with no problems. 
> From: trnw2-bounces at trnw.net <trnw2-bounces at trnw.net> on behalf of John Vanklavern via trnw2 <trnw2 at trnw.net>
> Sent: Wednesday, October 29, 2025 4:14 AM
> To: trnw2 at trnw.net <trnw2 at trnw.net>
> Subject: TRNW-2: 6L90, jmdz torque converter
>  
> Date: Wed Oct 29 2:14:23 PDT 2025
> Subject: 6L90, jmdz torque converter
> 
> I have a 21 chevy hd in the shop with a jmdz converter. I'm wondering what you guys are seeing with these in comparison to the jmbx. Are they as prone to failure? The main reason I'm asking is because this trans had no fwd with ball stuck in plate. When I called customer about it, he wanted me to overhaul and update trans anyway. I'm not going to argue with gravy. Trying to figure out if I should replace converter or reuse. trans has about 140k on it. besides my question, a general discussion about this converter would be nice. I understand it is a captive clutch.
> 
> John Vanklavern
> Jvk Services Llc
> West Olive, Michigan USA
> TRNW Member Since: 5/23/2025
> 
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