It could just be a solenoid or valve body issue. I would certainly want to rule this out before moving onto more involved running gear issues e.g. reverse clutch or low & reverse clutch faults. Dexron III (now VI) is the correct fluid for the GM 5L40-E transmission. For the TD6 : “When the...

This is the procedure outlined in RAVE for the original splined drive tube design: Although the ‘usual’ method would be to simply mark the nut and shaft when you remove the pinion flange, and then retighten to the same position following replacement of the seal, there’s a high risk that by...

What happens if you select Manual mode when stationary and then manually upshift through the gears as you accelerate? Phil

As the DTC seems to be wheel speed sensor related, and because you're losing drive, I think it would be worth checking your driveshafts Phil

If the drivetrain downstream of the transmission output shaft is disconnected from the wheels somewhere down the line (transfer box, propshafts, final drives or driveshafts), when the shift lever is moved back to the Park position the output shaft is still turning and this causes the park lock...

So this is the exact same issue that you had with the previous transmission installed? Clearly we’re still trying to establish if it’s a transmission fault or something else in the driveline like the transfer box. As long as you aren’t trying to tow anything or need to climb any steep hills I...

So what’s the current situation? Does the failsafe message reset so that when you next start the engine there’s no failsafe message displayed? What happens when you select Drive? Does the car set off in 1st gear and upshift through any gears or does the failsafe message immediately appear and...

Presumably your car has the uprated front propshaft mod. from the Q041 Service Action? I suggest you get the suspension on the highest setting and ask someone to look under the vehicle to see if either propshaft is turning when you’re stationary in Drive. Phil

Could be a seized cable clamp bolt in the selector lever: auto box issues - help please! Phil

Have you removed the plenum chamber? Phil

I assume that you’re referring to the 5-speed transmission? The E53 3.0 diesel used the GM 5L40-E up until the beginning of 2003, when the M57N engine was introduced along with the ZF 6HP26 transmission. The 3.0 petrol models used the 5L40-E as well. Because the L322 and E53 used different...

Yes, exactly. Phil

The common factor would appear to be the Low & Reverse clutch as it provides engine braking in 1st gear and is also used in Reverse. Its function is to ‘earth’ the inner race of the Low Clutch sprag. The clutch receives its hydraulic pressure from the Reverse Lockout Valve. I wonder if it...

For the ZF 5HP24 transmission, if the vehicle doesn’t move in reverse and there’s also no engine braking in Manual 1st gear, then the F-clutch/brake is faulty. Phil

Places like JPAT, Sussex Autoparts or Vanmatic may stock the direct clutch hub/shaft. If you’re going to strip a 5L40-E you need some seriously heavy-duty circlip pliers and a Seal-E-Zee cone set with freezing spray for the piston seals...

is it the dreaded box Phil

The L320 and L322 used identical 6HP26 transmissions. Both use the Magna Steyr DD295 transfer box. The transmission was updated through the years and you’ll see the transmission model number etched into the casing. Earliest models were 1068 020 054 (TGD 500470) which was superseded by 1068...

Worst case scenario: A re-manufactured torque converter from an official ZF parts centre like JPAT or Sussex AutoParts costs around £250-£300. It should take around 5 hours to get the transmission out and back in again. If an independent charges £65/hour, that’s around £600-£700 in total. A...

The Shell TF0753 fluid (p/n IYK 500010), referred to above, is for the Magna Steyr DD295 transfer box used with later models with 6- and 8-speed transmissions (capacity 1.5 litres). You have the New Venture Gear NV225 transfer box which uses Castrol BOT26 FMB1 75W-90 fluid (p/n STC 4861). It’s...

You have the ZF 6HP28 transmission. The transmission is far too complex for us to guess what the problem might be. You need to get the fault codes read and report back. Phil