Stuck in 4x4 low, No 4x4 lights on dash.

Roccafellas

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Long story short, I’m a mechanic, I would like actual techs or professionals only respond. Thank you.

Did up pipes and a tranny on a 6.4
Tranny is a #50 casting from a 6.0,
Replaced the TC with a 6.4 TC
Cut and spliced in a new TCM connector with the 10mm bolt going through it to the tranny..Old one had broken wires.

Now when I drive the truck I get up to 3rd or 4th and it stays and will not shift. It’ll stay at 2500rpm or more and I can’t get over 60kmh

Figured it’s stuck in 4x4 low as we used 4x4 low to put the truck up on the ramps when we did the work.

Now when we switch the 4x4 switch on the dash, NO LIGHTS, Come on the dash indicating it’s in 4x4 or Low etc.. And the TCASE will not unlock the front driveshaft..

What does anyone think could of happened in the middle of a tranny swap? I was searching a GEM module can cause this. But it worked COMPLETELY FINE. Before. The job. Lights for 4x4 and switch worked perfect. Thanks.


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6.0 Tech

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Electronic shift t case?

All the connectors plugged in good on the t case? Shift motor may be locked up if so. If it’s manual shift, the linkage could’ve gotten installed wrong or something along those lines.

Also, make sure the hubs are unlocked when verifying the t case is not I. 4x4. The front driveshaft will only spin until the little bit of slack is taken up, it will make it feel like the t case is still locked in.


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Roccafellas

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Electronic,
And if the motor was bound up, that would cause the light not to show up?
I read that there is a connector 2 wire I believe that grounds either for the high and low lights. Can anyone with a diagram confirm? I’ll try grounding both, I’m on Holidays for 2 months. And I won’t have access to AllData or Mitchell diagrams.


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Roccafellas

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Electronic shift t case?

All the connectors plugged in good on the t case? Shift motor may be locked up if so. If it’s manual shift, the linkage could’ve gotten installed wrong or something along those lines.

Also, make sure the hubs are unlocked when verifying the t case is not I. 4x4. The front driveshaft will only spin until the little bit of slack is taken up, it will make it feel like the t case is still locked in.


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And can you explain more about the hubs being unlocked and tcase spinning the front shaft? Not clear to me. Thank you.


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6.0 Tech

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And can you explain more about the hubs being unlocked and tcase spinning the front shaft? Not clear to me. Thank you.


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I’ll have to look up the wiring to make sure on the other stuff.

As for the hubs being locked, they will spin the front driveshaft when driving, as they are locked to the front wheels. And if you are just trying to spin the front driveshaft by hand without the truck moving, it will only take up about 1/4-1/2 in of slack in the hubs before not being able to move by hand anymore, as it will be trying to spin the front tires. If the tires are off the ground, it will move them, but be very difficult.


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Roccafellas

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I’ll have to look up the wiring to make sure on the other stuff.

As for the hubs being locked, they will spin the front driveshaft when driving, as they are locked to the front wheels. And if you are just trying to spin the front driveshaft by hand without the truck moving, it will only take up about 1/4-1/2 in of slack in the hubs before not being able to move by hand anymore, as it will be trying to spin the front tires. If the tires are off the ground, it will move them, but be very difficult.


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Okay yes I understand that. Pretty sure his hubs are unlocked. But even so if they were locked I don’t think it would keep the engine from shifting like its in a Low Gear.


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Roccafellas

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UPDATE: pin 2 on the encoder motor was corroded, yellow with white tracer, spliced in spare connector, all was good. Thanks guys!


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6.0 Tech

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UPDATE: pin 2 on the encoder motor was corroded, yellow with white tracer, spliced in spare connector, all was good. Thanks guys!


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Good deal man. Glad you found it


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