XC70 No Drive

[Marke21287]

Hi Guys,

I recently bought a 2005 XC70 2.5T with an AW55-51SN gearbox.

The vehicle had no drive when I bought it and the previous owner gave me a toasted gearbox with the car. Story goes, that the original box failed so he bought a second hand box and installed it but 7000km later it failed again.
He sent the vehicle to a Gearbox specialist and they reconditioned the box. But it failed 1000km later with no drive.

I have stripped the original box and found ALL the clutch plates toasted.
I then took the box out the car and found one set of plates toasted and the box oil very dirty.

I have put new plates in the box throughout, completed all the settings as per the manual. I also stripped the valve body that was full of dirt, put new gaskets and rebuilt it with the aid of manuals so I am 99.9% sure it is all correct.

I installed the box I rebuilt plus a recon torque converter but I get zero drive from the box.
On inspecting the oil flow to the oil cooler, there is not a drop of flow. I have no codes logged with the ECM or TCM.

I pulled the box again and double checked the oil pump and everything is right but still no oil flow in the box.

I am at a complete loss. Any ideas or thoughts would be appreciated.

Thank you

[VOLVOBOY]

Did you re-fit the bolts ; Torque converter to drive plate ?
Very easy to forget.
There are two o-ring seals behind the valve-pack which un-seat very easily when installing the valve-pack . If there is a leak here then no pressure & no drive.
Line pressure solenoid good ??
There are ports where you dury rig gauges to diagnose pressure problems which is what this sounds like.
Other than that possibly electrical .

[Marke21287]

Hello VolvoBoy, I appreciate your input.

Definitely put the bolts in the torque converter.

I have not pulled the valve body from the box again, so that is a great suggestion. I will check it out tomorrow.

I have tried to go through documentation to confirm which is the line pressure solenoid but I can not find a definite answer. Please guide me.

I have not tried the ports as to date, not a drop of oil has gone into the oil cooler on my new radiator, so there is absolutely zero oil movement in the box.
I have checked all the obvious. Pipes are clean, box is over full with oil expecting the level to drop when the torque converter fills, Double checked the oil pump in the box... really at a loss but the seal is a real possibility that it fell out on assembly!

Will check it out and let you know.

[VOLVOBOY]

Didn`t really think you would forget the bolts . If you can rebuild the box then then you know what you are about.
The best info i can suggest is to download pdf from internet the ATSG Repair Manual . It covers everything -mechanical , hydraulic , electrical and test .
This transmission is used on Saturn , GM , Saab , Nissan and is also called AF23/33-5 and RE5F-22A .
I have a feeling that i saw somewhere that the Torque Converter needs to be primed with oil when installing but i can`t find this at present .
SLU (black) is the line pressure controlling clutches and Torque converter .
SLS (greeen) controls shift pressures , and SLT (blue) the shift timing .

[Marke21287]

Thanks Volvo Boy. A couple of days before I will get time again to look at the box and then I need to get the engine back in! Will revert soonest.