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Thread: Shuddering

  1. #1
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    Shuddering

    Hey guys,

    I just recently put in a MTCM and a GETRAG 3.73. I now have a shudder between 15-20 mph… it comes on right at 15 mph and goes away right 20 mph. It only does it coasting in that range or coasting down. I have no vibrations or odd noises but It bucks pretty hard. I did install the MTCM a few weeks before the rear end, then pulled it in and changed the rear. After the rear change I updated it in the predator to the correct gearing and off I went. No other issues. When we did the swap I topped the diff off with the correct weight gear oil and added a small bottle of Lucas friction modifier.
    What do you think could be causing this? No limp mode and no weird noises…
    Thanks for your help.
    -Jake
    Inertia Premium Big valve heads, SRT Max Rumbler cam, 6.1L pushrods and lifters, MTCM, Getrag 3.73, 3200 rpm Edge stall, Kooks LT headers, Catless Mids, Borla 125 cat-back, AFE II CAI
    20" Viper Repro's w/ 315/35/r20
    Kenwood 6" Dvd/nav w/13" ED 1200 watt sub




  2. #2
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    Reset the transmission adaptives.

    first time out 11.28 @ 123.94MPH 1.89 60ft +3500DA R.I.P Kenne Bell

  3. #3
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    I can do that with the MTCM in and whatnot and not mess anything up?

    -Jake

  4. #4
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    Did you follow the instructions for installing the MTCM? both from diablo AND the adaptation process from MOPAR that comes with the MTCM? numerous threads about that. Do you have the MDS turned off?
    I had similar problems ans turning off the mds solved most of it.

    I have one similar issue to you. at part throttle in 1st gear ( autotick) the TC likes to lock up/ unlock, causing the rpms to surge. same speed as you desribe. I overcome this issue with a firm application of my right foot.

    hope this helps
    08 R/T LMI TRUE CAI, eagle intake, 6.1 injectors. Modern Muscle Performance Group 85mm Ported TB, big CAM, and ported eagle heads. SLP UD pulley. 6.1 timing set,and lifters, PSI springs custom pushrods, cometic head gaskets, 11:1 comp. American Racing 1 3/4" long tube headers, highflow cats with Magnaflow 3" mufflers, 4" tips., catch can 170 stat. Builder Bill rebuilt tranny, stage 2 valve body, 3500 stall TC, AFI flexplate. Getrag 3.73 MTCM. BC Coilovers. Pistol grip shifter. 417 RWHP, Dyno Tuned by Brent @DTP.
    NEW04/6/14: 11.744 @ 117 mph .

  5. #5
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    reset the adaptives only if you installed your MTCM properly...put car back to stock tune, remove old tcm, install new tcm, take back up of stock tune and this will now take a back up of the MTCM program..install your tune...then do adaptives procedure...

  6. #6
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    Yea the MTCM was installed properly as was the adaptives procedure. With that being said can i just hook my predator up and reset the tranny adaptives? Im not sure if it does it in autostick or not, but ill check.

    -Jake

  7. #7
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    Did you install a spacer between the differential and the pinion spacer. Not doing so has resulted in a whine and or vibration in many cars making the switch to the Getrag. Read the posts in this thread for further.

    http://www.lxforums.com/board/f325/t...-whine-221497/

    I added a 1/4" spacer when I installed my Getrag and haven't had an issue.
    Last edited by fireman2118; 01-11-2012 at 07:08 PM.


    PPP stage 3 big valve heads, Howards cam 219/227 .600/.575 112 +4, MMPG stage 1+ ported 6.1 intake & 85mm throttle body, LMI 4" true CAI, MSD "Blaster" coils, JBA headers & mids, Corsa exhaust, Paramount series 55 transmission, "Dominator" torque converter & stage 2 valve body, BC Racing coilovers, Eibach sways, BWoody links, Razorsedge brace, 226mm Getrag 3.91 LSD, Wilwood "plus 2" big brake kit by TCE, tuning by Robert Dito of Ditos motors


  8. #8
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    Quote Originally Posted by Moparjake View Post
    Yea the MTCM was installed properly as was the adaptives procedure. With that being said can i just hook my predator up and reset the tranny adaptives? Im not sure if it does it in autostick or not, but ill check.

    -Jake

    I have reset the adaptives with the MTCM in, anything you can do in the quick adjust settings wont brick the TCM.

  9. #9
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    Sounds good. Ill give that a try and see what it does...we just got a fresh dusting of snow so...itll have to wait a few days.

    Fireman - Yeah I installed a washer between the case and isolator on the front bolt...like i mentioned no whine or noises at all. She just bucks like crazy in 15 to 20 mph. Its odd because it doesn't do it at any other speeds and only in that range when coasting or idling down.

    -Jake

  10. #10
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    Torque converter?
    Last edited by fireman2118; 01-11-2012 at 10:30 PM.

  11. #11
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    Could be TC, but more likely tune. Just in case, do a datalog and see what shows up. If you have a CMR tune, I'd put your tuner on alert that some adjustments may be necessary.

  12. #12
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    Hey guys,

    Im still having the issue. I reset the TCM adaptives, re-input my gear ratio and reloaded the tune. It bucks hard from 15 to 20 mph only coasting. Ive not logged it but it happened literally once i installed the Getrag. Could this be from too little or too much friction modifier? Id really like to find a solution to this.

    -Jake

  13. #13
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    What are your rpms doing when the car is bucking? Does it feel like a stick shift that is in too high of a gear when you let off?
    JBA shorties catless mids and SLP Loud Mouth I, K/N typhoon, powerbond undrive pulley, 170 tstat, mopar TCM, blue tops, R1 crossdrilled/slotted rotors, HAWK Pads, SRT MAX on 112, CNC Inertia Heads milled, 3000 Edge converter 3.91 Getrag 09 axles installed!#157 of 1400
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  14. #14
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    The RPMs stay and don't move up and down with the bucking. It does feel like your describing. The odd thing is that it only happens in that 5 mph range and only with my foot off the throttle. The only thing that really concerns me is it's pretty violent.

    -Jake

  15. #15
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    I have that now and again, I think its a torque management issue in the tune. I have almost the same set up as you and its fixable. Call Stu and we can have him adjust it, myself I will live with it becasuse I feel the WOT's are much better set up this way

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