Hi I'm new to this forum. I have a 2001 cummins
Recently I rebuilt tranny. It appears lock up won't lock up. Shop has replaced speed sensors, and Tcc solenoid 2 times now. And he insists its not the torque. I've check all the grounds I can find. I've put foil around alt wire and tied it up out of the way. Still not working correct. Rpm is up around 2300 used to be 1750. It only does this when I'm pulling my 14' enclosed trailer and only since tranny was rebuilt.

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I might add I've been driving it like this since oct. and it hasn't gotten any worse. It's just screaming and driving me nuts. Very hard on fuel as well. Anyone might know anything at all.

 

sounds more like you lost overdrive.

 

Thanks for your reply. This really stumps me cause when I click the overdrive off it still jumps up in rpm like up to 2800

 

no overdrive and no lock up if its that high of rpms. what speed?

 

Around 2800

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Sorry that was 2800 at 100km or 60 mph. This only happens while I'm towing. When not towing the shift 3-4 and overdrive and lock up are real slow to shift.

 

You need to put a gauge on the OD port to see what pressure it has. I have seen them pop the seal on the OD piston and do what you are experiencing.

 

Wow really. Should most tranny shops be able to do this.
Thanks by the way. I'll see if I can get him to check that.

 

also if your brakes are activated, this will kick the tranny out of lock up... dunno if it will help any but its an idea.

 

I just had a friend look at it this morning, he scanned it and came up with governor pressure is lower than what is preferred. And lock up seems to be not engaging fully. When I tap the breaks with foot on acc. Pedal tach jumps only about 25-30 rpm. If anyone might gave some insight on this subject please help me. I'm hoping I don't have to redo tranny

 

I have the same problem, took it to the tranny shop and they cannot find the problem other than suggest the harmonic balancer outter "ring" might have become a bit out of round over the many miles. (387,000). Tried the aluminum foil, cleaned the grime from the harmonic balancer. This did not cure the problem so I am still on the hunt.

Suggestions?