6A13TT auto gearbox jerking

[3309]

Hi all otai and sifu,
I have a query on 6A13TT auto gearbox.
I transplant this engine into my Naza Ria.
Everything is fine except for gearbox.
It is jerking at 3rd gear only.
Have changed the oil a few times already but still the same.
And have check the wiring and sensor also no problem.

Can someone advice what might be the problem?
Have sent to 3 wshop already but problem still there.

 

[DanzEterna]

could be the TCU or valvebody.

 

[3309]

Valvebody already serviced before because unable to engage gear at all.
What is TCU?

 

[DanzEterna]

Valvebody already serviced before because unable to engage gear at all.
What is TCU?

Transmission Control Unit, ECU that controls the autobox.

 

[3309]

This TCU not repairable right?
Where can I get it?

 

[DanzEterna]

not sure, try asking former Levin forgot the number behind, he repairs ECU not sure bout TCU.
y not diagnose it 1st.

u got OBD2 Bluetooth reader?

 

[3309]

Danz,
Maybe I should try a better ATF oil as suggested by LittleWhiteWagon.

 

[DanzEterna]

u have an ATF cooler installed right?
could try those oils recommended by LWW.

 

[3309]

Yes I have. Thanks.