2018 t680 with automated eaton 10 speed
04-01-2026, (Subject: 2018 t680 with automated eaton 10 speed ) 
Post: #1
2018 t680 with automated eaton 10 speed
SPN 788 FMI 7
SPN 560 FMI 11

I was switching trailers one day, the lower gears seemed to be grabbing really hard and when I put it in Neutral, the truck shut off and wouldn't turn on until I pulled the fuse for the trans. These are the codes I was getting.

I drove another 300 miles and it did it again when I put it in N but was able to turn back over. Everything seems to be working okay but the faults stay.

The only other issues I've had is a SPN 752 FMI 2 when it rains really hard. Then the truck won't shift anymore until it dries off and then it starts working again. Code disappears.

I took it to a shop and they said the clutch was broken and something about the spring...

I've been told there is still clutch left from another mechanic and I don't see how the clutch could be broken.

What do you guys suggest?
replyreply
04-02-2026, (Subject: 2018 t680 with automated eaton 10 speed ) 
Post: #2
RE: 2018 t680 with automated eaton 10 speed
I don't know anything about these auto trans but I would say your issue with the rain is something electrical. You might be dealing with more than 1 issue here.
replyreply
 Thanks given by: Rawze , Toolguy
04-02-2026, (Subject: 2018 t680 with automated eaton 10 speed ) 
Post: #3
RE: 2018 t680 with automated eaton 10 speed
I'd find out which wire and connector(s) it runs to, make sure the pins are clean and in all the way. Then check if you don't have a break in a wire which FMI 2 usually means with intermittent connections. All you may need is a 50 cent heat shink crimp and 15 minutes of your time..
replyreply
 Thanks given by: Rawze , Toolguy




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