8hp70 tcm?

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Ram1683

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Well I'm at my wits with this unit. I found a unit with under 1000 miles on it I may go pick up. My question is do I have to swap my TCM into the new trans?
with my unit No matter what I do it won't shift right. I've had the pan down more times than I care to remember and have thrown away hundreds on fluid. Few hours ago I deleted the revmax kit and gave it a belly full of maxlife. Trans holds a steady 165-170 now but its never felt so bad. Shifts either flare or delay. When it does shift it feels like the trans in full of mash potatoes. I'm leaving the battery disconnected till around noon tomorrow. Maybe it'll relearn
 

crash68

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The TCM is part of the 8HP valve body inside the transmission.
Fluid level is critical with these transmissions, double check it's correct.
 
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Ram1683

Ram1683

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Yeah I've had the valve body down on that before. I did the fluid as per book. Trans level. Right temperature. Cycled gears and it was pouring out. I'll double check it though tomorrow
 

ThunderMug95

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Have you thought about getting a custom tune? There are several known and well proven tuners for our 5.7/8HP70’s. They tune the trans, shiftpoints.
I use Hemifever and my trans shifts awesome.
This won’t fix a mechanical issue, but it sure as heck is worth a shot.
 

danielmid

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Hemifever's tune definitely made a difference but I'm opened minded If I do swap units
If you go look at his post he has contact info, I've seen him on the HP Tuner forum so I'm not sure what the process would be for conversion from HF tune.
 
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Ram1683

Ram1683

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Does the Diablo tuner let you flash transmission tune separate from the engine tune? If so, have you tried going back to the stock tcm tune?
Wow honestly I didn't even think of that, good call. I think it does but don't qoute me on that. . Tomorrow if fluid level is good I'll give that a check
 

ThunderMug95

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IIRC, it prompts you to add the ZF tune to one of the canned tunes, but I cannot swear that when you flash the Custom/HF tune if theres an option to leave off the ZF tune. I want to say yes though.
 

t0ymach1n3

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I can tell ya, you 100% can swap a TCM from one trans to another with nothing more than a VIN write with Alfa and you're golden. Did it to mine after finding out the TCM had been previously tuned with a DiabloSport, which wasn't gonna work with HP Tuners. I have had ZERO issues and the transmission operates flawlessly.
 
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Ram1683

Ram1683

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I can tell ya, you 100% can swap a TCM from one trans to another with nothing more than a VIN write with Alfa and you're golden. Did it to mine after finding out the TCM had been previously tuned with a DiabloSport, which wasn't gonna work with HP Tuners. I have had ZERO issues and the transmission operates flawlessly.
That's kind of where I was worried. I wasn't completely sure if I needed to swap TCM to another trans because they're married. What's alfa?
 
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