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  1. #1
    Join Date
    Jun 2019
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    NAG1 3-4 Shift Flare, 05 Magnum

    Hey Folks! Long time anonymous lurker, first time poster.

    I have a 2005 Dodge Magnum RT, totally stock with the NAG1 transmission and 131K miles. Daily driver, no track or mods. Car shifted fine 99% of the time, except in prlonged and heavy stop and go NYC traffic where I'd get a hard 1-2/2-1 shift. I purchased the car back in '09 with about 75K miles on it and decided it would be a good time to do fluid/filter swap. While in there, I decided I'd drop the valve body and proactively do a Sonnax Overlap Control Valve sleeve kit. Since I was going that far, I picked up the Transgo 722.6 kit as well, and installed their "updated" Pressure Regulator Valve and Lubricating Regulator Valve.

    I reassembled the valve body, torqued everything to spec, added my ATF+4, used my Autoenginuity scan tool to pull temp and added fluid to hit level recommended on the curve. The car shifted smooth as silk, even better than before.......except for third to fourth. Keeping my foot on the throttle with all shifts up to 4th, the transmission seems to go to neutral, RPM's rev up, then lands relatively smoothly in to 4th all in about 1-2 seconds. 3-4 shifts (with the autoshifter) with my foot of the gas are smooth.

    Thinking I fudged something, I pulled the valve body again. I replaced the o-rings on the 3-4 solenoid and confirmed resistance on the solenoid against spec. I also pulled all four of the 3-4 valves, looking in each hole for any debris, scoring or anything that jumped out at me. Nothing.

    I'm at a bit of a loss on next steps. I dont think its the K3 since I didn't have any 3-4 problems before the fluid swap, but may be the fluid swap made the clutches angry?

    I had considered pulling the valve body and splitting it open to clean out the channels. A bit gunshy to do this though since I may create more problems.
    Also considered pulling the transgo parts, but having smooth shifts except for the 3-4 seems to rules those out as faulty.

    Wanted to reach out to the audience and see if y'all had any ideas. Thoughts, comments or feedback are appreciated! Thanks in advance!

    -A



  2. #2
    Join Date
    Feb 2015
    Posts
    1,003
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    I personally don't like transgo products. They are bandaids for bores that have become oversized due to wear, and they "fix" the issue using oversized O rings to seal the gap. Atleast that's my experience with their audi kits for the zf transmissions, the proper fix in that case is to enlarge the bore so it can fit an oversized valve/pressure regulatod with the proper o ring sizes.

    I'm not sure about the sonnax kit as I've never used it, but iirc we used to purchase valve bodies for the zf transmissions from them that were already bored out to fit the oversized pressure regulator since they had all the tooling already.


    The other thing is, the slightest bit of dirt is enough to make a check ball stick in a valve body, even a piece of lint from a shop towl could do it. If you take it apart you need to do it in a clean area that's dust free.



    So personally if you didnt have any problems with what ever the transgo kit was meant to fix, if those parts are related to the 3/4 shift, I'd put the stock parts back in, just make sure they are spotless before hand.


    Also I'm no expert with the nag1, it's a complicated beast of a transmission that I haven't been willing to tear down and I haven't been in that line of work for a few years. So I'm sure some one here can chime in with more info.


    I have close to 160k on mine, with some track use, and I drive the heck out of it all the time, only issue I have is a faulty input speed sensor as of a few weeks ago. I also have a gen1 tranzformer that I use to really firm up the shifts, on top of what ever my diablo tuner does to increase it, when it's all turned off it shifts so smooth I can only tell it did when the rpm drops.




    Sent from my SM-N900V using Tapatalk
    2005 Brilliant Black 300C
    Qtp dual oval cutouts, LegMaker True V2 CAI
    ZAuto Tranzformer, Diablo Trinity 93 canned tune, Hoosier Dr2

  3. #3
    Join Date
    Jun 2019
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    2
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    Hey blistering,

    Thanks for the response.

    I decided to pull the valve body (yet a third time), this time on a mission to split the valve body and clear the channels with brake cleaner or mineral spirits. Splitting open the valve body didnt yield anything blatantly obvious. All channels looked clean. No metal shaving or possible obstructions. I pulled all the filters, plastic and steel check balls and inverted the valve body to clear out any remaining fluid.

    At that point, I decided to manually actuate all the valves in the upper and lower valve bodies to check for anything stuck or obviously loose. Every valve actuated OK, except for the 2-3 O-lap regulator valve in the upper valve body. The valve would compress, but didn't seem to return to a proper resting position like every other valve. I pulled the valve cover plate and AH-HA! The spacer in the 2-3 Overlap valve the seats the spring was missing! A quick check of my removed factory parts showed that I mistakingly left the spacer in the old overlap value. Oops. Needless to say, I put the part back in and the car shifts fine.

    Quite odd though. I drove the car without that spacer for over 100 miles. My 2-3 and 3-2 shifts were perfect. Only my 3-4 upshift experienced flare. Would be curious to understand why I had no issues with 2-3...

    Regardless, case closed. Thanks again for your feedback.

    -A
    Thanks blue_devil, blistering thanked for this post
    Likes Carpaltomo, blue_devil liked this post

  4. #4
    Join Date
    Dec 2018
    Posts
    32
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    I'm glad to read you found the problem! I just discovered there was an inner sleeve myself, after watching a YouTube video on the swap. I myself need to do this job before the holidays, it's definitely intimidating!

    722.6 Complete Valve Body Rebuild & Clean Timelapse - YouTube
    Last edited by blue_devil; 11-09-2019 at 12:44 AM.
    2006 (Manu.Date 5/05) Magnum RT (midnight blue) - STOCK... Rolled over 100K on the OD. Just general maintenance for now.

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