Caterpillar 140H transmission problem

[andu]

ok sir,
when I keep the orginal wiring and interchange the two vakves it remains the same(the probkems is no.2,3 and 6 forwards).and I change the new valve body with new solenods.even it is the same.
Additionaly I try to check externally the current for each solenoids(no.3,1 and 2) when it works they are the same and the close the valve body.and again I fix it back to the control valve still the same.

 

[Nige]

So interchanging either just the solenoids alone or exchanging the complete solenoid valves makes no difference.?
The problem remains no 2/3/6 speeds Forward.?

Please can you try to explain clearly exactly what you did to make the problem move from 2/3/6 to 1/4/5/7/8.

 

[andu]

So interchanging either just the solenoids alone or exchanging the complete solenoid valves makes no difference.?
The problem remains no 2/3/6 speeds Forward.?

Please can you try to explain clearly exactly what you did to make the problem move from 2/3/6 to 1/4/5/7/8.

the problems move from 2/3/6 to 1/4/5/7/8 was when I exchanged the wiring only.(the solenoids and the valves ramian onthier orginal place).

 

[Nige]

Now I think I understand.

The problem appears to be either in the electronic transmission control or in the chassis wiring from that control to the transmission. You will need an electrical schematic to do the testing. I will send you a copy.

I would suggest to first check the continuity of the short harness right on the transmission that has the solenoid connectors on one end and a large connector to the chassis on the other end. This harness should be secured to a steel "ladder" with zip ties.

 

[Nige]

I would suggest to first check the continuity of the short harness right on the transmission

This one. The harness suffers from heat-cracking of the insulation because of how close it is to the hot transmission