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Thread: 68rfe problems.. gear 2 incorrect ratio Reply to Thread
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  Topic Review (Newest First)
04-05-2019 08:58 PM
TransEngineer
Quote:
Originally Posted by cummins_fanatic View Post
upon disassembly the overdrives, and 2c clutches were burnt up. the cause of the problem i believe was the spin on filter not 100% seating, and therefore losing oil pressure under higher pressure . I got it rebuilt and installed yesterday. i put 600km on between last night, and today, and its running awesome. Thanks for the help.
Glad you got it fixed!
04-05-2019 08:23 PM
cummins_fanatic upon disassembly the overdrives, and 2c clutches were burnt up. the cause of the problem i believe was the spin on filter not 100% seating, and therefore losing oil pressure under higher pressure . I got it rebuilt and installed yesterday. i put 600km on between last night, and today, and its running awesome. Thanks for the help.
04-04-2019 09:09 AM
cummins_fanatic well upon disassembly the overdrives are burnt up. there is zero clutch material left.
04-03-2019 05:41 PM
cummins_fanatic i found the pin out in my Chrysler shop manual. i will proceed to check the pin-outs. i also air checked od-ud-reverse again, they all operate correctly.
04-03-2019 01:43 PM
TransEngineer
Quote:
Originally Posted by cummins_fanatic View Post
the P0933 only shows up at the same time i get the P0734. ive got 3 different sensors that ive changed, one of them was brand new. if i put a meter on the line pressure plug, where do the wires run back to, that i could test.
The wires run to the PCM. You'd have to search online for a wiring diagram to get the pinouts on the connectors. You can try rambodybuilder.com.
04-03-2019 01:36 PM
cummins_fanatic the P0933 only shows up at the same time i get the P0734. ive got 3 different sensors that ive changed, one of them was brand new. if i put a meter on the line pressure plug, where do the wires run back to, that i could test.
04-03-2019 12:51 PM
TransEngineer
Quote:
Originally Posted by cummins_fanatic View Post
changed my pressure sensor, and did some more test driving this morning. torque converter didnt stay locked up once, and now im only getting codes P0734 Gear 4 incorrect ratio. and P0933 Hydraulic pressure sensor. when i pull it out i will concentrate on 4c clutch, and pump.
Fix the P0933 before you pull it out. That code can indicate a bad LP sensor (which obviously shouldn't be the case now), OR a bad connection (LP sensor connector not fully seated and latched), OR bad wiring (in one of the LP sensor circuits). Since a wacky LP reading can cause bad line pressure (which can lead to slippage, and therefore ratio errors), I would get the LP sensor issue fixed and see if that corrects the ratio error.

And the 4C clutch is used in 3rd and 5th gears, so the problem in a P0734 is usually the OD clutch.
04-03-2019 12:51 PM
cummins_fanatic Line pressure at idle in park is 100-130psi
in drive with brake on 71-85
in reverse with brake on 200-220
04-03-2019 12:42 PM
cummins_fanatic changed my pressure sensor, and did some more test driving this morning. torque converter didnt stay locked up once, and now im only getting codes P0734 Gear 4 incorrect ratio. and P0933 Hydraulic pressure sensor. when i pull it out i will concentrate on 4c clutch, and pump.
04-03-2019 12:40 PM
TransEngineer
Quote:
Originally Posted by cummins_fanatic View Post
does it seem weird that the TCC only drags once everything is running for a while and warmed up? once i pull the pump out, how would i go about testing the TCC Control valve? just visually, and that it has clean free movement?
Yes, check the valves that they slide freely in their bores. Also check for bore wear: there should be almost NO gap between the valves and their bores (it should be like .001"). Shine a flashlight over each bore and see if you can see light around the valve anywhere.

TCC drag can be caused by loss of line pressure, so if that happens only when hot, could be the pump itself is worn and not able to keep LP up at idle. Best way to diagnose that is to simply read the line pressure at idle (using a scan tool) and see if it's stable. It should be 40 psi or higher.
04-03-2019 12:06 PM
cummins_fanatic does it seem weird that the TCC only drags once everything is running for a while and warmed up? once i pull the pump out, how would i go about testing the TCC Control valve? just visually, and that it has clean free movement?
04-03-2019 10:31 AM
TransEngineer
Quote:
Originally Posted by cummins_fanatic View Post
is there anyway to test the pump? air tested all of the clutches again, they all sound good. i guess i will pull it back out.
No, there is no simple way to test the pump. Normally, you could monitor the line pressure and see how well it can maintain the desired LP level. But because you're also having issues with the TCC function, I suspect you may have a sticky or worn TCC control valve (in the pump), and the only way to check that is to pull it out and inspect it.

If the TCC is dragging in 1st and/or reverse, and the pump is OK, then the converter is bad internally.
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