TC won't stay locked on new trans

Delaware6.4 · Apr 11, 2014

Hey guys, just signed up hoping you can help me out. I have a built trans from MPD and it will not keep the TC locked if I give over 20% throttle in 4th and 5th. It also shutters hard trying to lock it. Will eventually lock at about 80. I have mcc and matts tunes. Any advice would be great thanks.

MINK · Apr 11, 2014

Whose converter? Have you contacted mpd? ...could be a pump issue, is it the original?

Delaware6.4 · Apr 11, 2014

MPD uses a local guy that makes them. It's actually the second one in 3 months. MPD says it's a tuning issue. I just got it back Tuesday. I have read that other guys have had the problem but didn't seem to find a good answer

Delaware6.4 · Apr 11, 2014

And with matts tunes the tc is supposed to lock in 2. It currently locks in 3 but will unlock and lock repeatedly about 6 times until 5th at WOT. I'm pulling tomorrow and a bit nervous about my 6k trans

Delaware6.4 · Apr 11, 2014

Somebody on here has to be familiar with this issue. I have read old posts where Others have had this same problem. Should I try Eric's tunes?

range91 · Apr 11, 2014

I can't see your sig for mods but run stock tune and see how it acts. Have you either replaced the coolers or flushed to get contamination out?

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Fordtrucks · Apr 12, 2014

Try re downloading the tune? Maybe try a different tune?

Delaware6.4 · Apr 12, 2014

I have tried both mcc and matts tunes. Matts make the truck run a bit better. Truck won't lock and unlock as often at WOT. In stock, it will hold once I am in 4th but is still supposed to lock in 2. BTW my TCM is new and wire harness was checked so we can rule that out. Mpd said my stall is same as stock All I have for mods is intake exhaust and batmo's. I am pulling at cecilton today so I'll stay with gearhead tunes and let u guys know how I do. Thanks a lot for the input

Delaware6.4 · Apr 12, 2014

Range: I just replaced radiator 2 weeks ago before it went back to mpd to get new TC and valve body. Coolant is new. Have noticed recently that the degas bottle has a dark stain in it but is ok now due to new coolant. Do you think it could be related?

range91 · Apr 12, 2014

Contamination in the add on cooler can cause all sorts of problems it's never good to have metal or clutch going through a fresh trans. It also could be misaligned tcc bushing in the pump. Did you try stock tunes?

Delaware6.4 · Apr 12, 2014

Stock will hold. Went pulling today and truck shut down hard at 3000 rpm like the traction control was on but I was in 4 low. Would not shift out of 1 Tried both h and s and matts tunes. When on the street It breaks the tires loose when TC locks in 3rd but will unlock immediately into 4th