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Bad batteries kill transmission!?

2449 Views 10 Replies 4 Participants Last post by  skinnyvito
So I took my truck to a highly recommended shop in my area because my lights were flickering.I checked my connections, batteries and alternator were less than a year old so I thought a pro could figure it out fast. He did,bad batteries( crappy tire) but on a test drive he lost 2 gears in the transmission! I just bought a NADP Heavy Hauler this summer WTF! NAPC says I had a electrical problem first, it's an electronic trans.... I didn't drive long with the problem, trans light never showed up while I was driving, and I haven't drove at the hp I told NADP I was shooting for. NAPC is talking to the mechanic about it, I hope there gonna warrantee it, i did not wanna buy myself a trans for Christmas. So if in doubt don't b cheap buy 2 new quality batteries.
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Bad batteries will not kill your transmission. If your system voltage falls too low, the TCM will set a Low Battery Voltage fault, and may put you in limp-in, but that will not kill the trans.

Which two gears did you lose? How does the trans drive now? What does it do (or not do)? No shifts into 5th or 6th? Got any faults or CEL? Does it shift normally 1-2-3-4?
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Yup, sounds like the OD clutch is not holding full torque. Likely a P0735 Gear Ratio Error in 5th.
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