4L80E Shifting Problems

[Desert Rider]

I have a

1993 3500 Dually with 454 TBI and the 4L80E transmision (150k mi on original trans, worked great till now), I tow a 30 ft Toy Hauler that is 8700lb dry.

I have already serviced and replaced the 1-2 and 2-3 shift solenoids.

My problems are

1 When I pull away from a stop the trans will stay in what seams like 2nd gear accept no engine breaking. if I select 2nd gear it has engine breaking so I am not sure that it is realy in 2nd. This kind of comes and goes.

2 When I am in OD at speed in 4th gear it will gust drop into 3rd gear and will not go back into 4th gear unless I stop and restart the truck.

 

Thanks

Scott

[Desert Rider]

Hi everyone,

Just thought I would that I resolved the problem.

The insolation on wires to the forward speed sensor had been damaged from a small leak from the speed sensor and where shorted together.

And still no code!!!

Either way I am back on the road with all 4 gears

 

Desert Rider