2006 RRS 2.7 tdv6 gearbox help please

Have you got 12v and an earth at the tcm?

dave7494 said:

I’m hoping and praying it’s something silly. Would I be correct in saying the parking assist module is in the boot behind side carpet?

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Good question

You have the ZF 6HP26X transmission and the Magna Steyr DD295 transfer box. The Fuse 37 thing only applies to L322 models with the earlier New Venture Gear NV225 transfer box used with the 5-speed transmissions (ZF 5HP24 & GM 5L40-E). It’s not relevant to the L320 as your vehicle can be towed on all 4 wheels without having to put the transfer box in Neutral. So, forget the fuse thing.

The most common reason for a 6-speed model to completely lose drive is because of a drive disconnect downstream of the transmission. This could be due to the transmission output shaft splines failing through fretting corrosion, a transfer box issue or a driveshaft popping out. However, the fact that your Park lock holds the vehicle indicates that none of these apply in your case.

You say that your dashboard lights display the gear selector lever position correctly. This tells us that the shift cable is connected, adjusted correctly, and (as you can see in the photo) the manual valve in the valve block assembly must also be moving because the slider for the gear position switch in the Mechatronic unit is connected to the rooster comb via the manual valve.



Even if all the electrics and electronics failed, the manual valve will still direct hydraulic pressure to the B and E clutches, giving you 5th gear, in Drive and to the B clutch & D brake in Reverse. The fact that your vehicle won’t move indicates that either a) there’s no hydraulic pressure getting to the clutches or b) you’ve had some form of mechanical failure in the running gear.

For a), the most obvious possible cause is low fluid level i.e. the pump is sucking air. However, you’ve checked the fluid level and it’s okay. Another common reason for no oil pressure is, if the transmission has been removed and then someone failed to align the pump drive dogs with the torque converter during the reinstallation, the drive dogs shear off when the bellhousing bolts are tightened. How sure are you that the transmission hasn’t been removed and re-installed?





For b), a mechanical failure could take many forms. One thing to check is that the input/turbine shaft turns (at engine speed) when the transmission is in Park or Neutral, but then is stationary when you select Reverse or Drive. Diagnostic kit that can report live values would be able to tell you this. The fact that the starter motor is out, you don’t think that they’ve removed the drive bolts between the flex plate and the torque converter or something silly like that, do you?

Phil

Wow thank you very much for the time to help and write your advice. Yeah the starter motor was removed , I reinstalled it but didn’t think to check anything around it. It makes no sense as to why they would remove it for what they claim “getting ready to remove the body”

Where do I look for the bolts from flex plate to torque converter?

Thank you again

I’m not familiar with the 2.7 V6 engine, but usually there are rearward facing access plugs that you can remove on the engine



or sometimes they use the starter motor hole for access (hence my suspicion). Clearly, this is a very long shot.

I would strongly recommend that you get access to some diagnostic kit that can tell you the input/turbine shaft speed.

Phil

Bemble said:

I’m not familiar with the 2.7 V6 engine, but usually there are rearward facing access plugs that you can remove on the engine

or sometimes they use the starter motor hole for access (hence my suspicion). Clearly, this is a very long shot.

I would strongly recommend that you get access to some diagnostic kit that can tell you the input/turbine shaft speed.

Phil

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I’ve just plugged in my diag and found the turbine speed in the live data and it’s at 0 and stays at 0 when cycling through RND sport and manual

Bemble said:

I’m not familiar with the 2.7 V6 engine, but usually there are rearward facing access plugs that you can remove on the engine

or sometimes they use the starter motor hole for access (hence my suspicion). Clearly, this is a very long shot.

I would strongly recommend that you get access to some diagnostic kit that can tell you the input/turbine shaft speed.

Phil

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Also , I’ve just jacked up the car to check around the starter and I can now confirm that when the car is in park I can infact turn the wheels.

dave7494 said:

Also , I’ve just jacked up the car to check around the starter and I can now confirm that when the car is in park I can infact turn the wheels.

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Don’t fall into a trap.
Please describe what you did better.

J

marjon said:

Don’t fall into a trap.
Please describe what you did better.

J

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Hi , sorry , I jacked up the pass side of the car (car is lhd) so drivers side uk , car was in park with hand brake off and I slid against the front wheel getting back up from being under it and the front and rear wheels move freely

Do you mean that both wheels on one side of the vehicle are off the ground and, if you turn one wheel, then the other turns too? If so, that's just the centre differential doing its thing i.e. the front propshaft is connected to one side gear and the rear propshaft to the other so, even if the carrier is locked, the side gears can rotate at the same speed in opposite directions as the planets rotate on their own pins without turning the carrier.

Anyway, going back to the turbine speed measurement, because this is significant.

• In Park the turbine speed should be the same as the engine speed (actually, probably slightly lower, due to the drag)
• With Reverse selected, the turbine speed should be zero
• In Neutral it should be the same as engine speed (again, probably slightly lower, due to the drag)
• In Drive it should be zero

Could you please confirm what these four readings are from your diagnostics?

Phil

Bemble said:

Do you mean that both wheels on one side of the vehicle are off the ground and, if you turn one wheel, then the other turns too? If so, that's just the centre differential doing its thing i.e. the front propshaft is connected to one side gear and the rear propshaft to the other so, even if the carrier is locked, the side gears can rotate at the same speed in opposite directions as the planets rotate on their own pins without turning the carrier.

Anyway, going back to the turbine speed measurement, because this is significant.

• In Park the turbine speed should be the same as the engine speed (actually, probably slightly lower, due to the drag)
• With Reverse selected, the turbine speed should be zero
• In Neutral it should be the same as engine speed (again, probably slightly lower, due to the drag)
• In Drive it should be zero

Could you please confirm what these four readings are from your diagnostics?

Phil

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Hi Phil ok that makes sense. I can confirm the turbine speed did not change from 0 when in P R N D sport

Okay, that sounds pretty serious, I’m afraid. My guess would be that the input/turbine shaft has snapped, or possibly an internal failure in the torque converter. Unfortunately, there’s a limit to what you can learn from diagnostics as nobody thought to allocate a DTC to a failed input shaft!

I’m afraid that the only way to confirm this is to remove the transmission, slide off the torque converter, and visually inspect the shaft/drum.



If you have access to a ramp and you’re handy/confident with a set of spanners this is definitely something that you should consider doing yourself.

Stripping/repairing/reassembling the transmission is easy compared with getting the damn thing out of the vehicle & back in again.

Phil

Bemble said:

Okay, that sounds pretty serious, I’m afraid. My guess would be that the input/turbine shaft has snapped, or possibly an internal failure in the torque converter. Unfortunately, there’s a limit to what you can learn from diagnostics as nobody thought to allocate a DTC to a failed input shaft!

I’m afraid that the only way to confirm this is to remove the transmission, slide off the torque converter, and visually inspect the shaft/drum.

If you have access to a ramp and you’re handy/confident with a set of spanners this is definitely something that you should consider doing yourself.

Stripping/repairing/reassembling the transmission is easy compared with getting the damn thing out of the vehicle & back in again.

Phil

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That doesn’t sound fun. Out of interest, if they had removed the bolts from the torque converter and that’s why the starter motor was removed , would this cause the issues im having?

When I remove the starter motor what am I looking for to see if the bolts are there or not as I can’t really find any good pictures or videos online about this side of it?

Yes, if the four drive bolts had been removed this would explain your issue, but it would be a pretty weird thing for them to have done. This is what your Y85 converter looks like on the back – you can clearly see the 4 bolt positions.


I did wonder if this hole in the engine casing, just above the starter motor, might be the aperture through which these bolts are accessed?



You have to turn the engine by hand until each of the bolts, in turn, appears in the window.

Phil

Bemble said:

Yes, if the four drive bolts had been removed this would explain your issue, but it would be a pretty weird thing for them to have done. This is what your Y85 converter looks like on the back – you can clearly see the 4 bolt positions.

I did wonder if this hole in the engine casing, just above the starter motor, might be the aperture through which these bolts are accessed?

You have to turn the engine by hand until each of the bolts, in turn, appears in the window.

Phil

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Perfect thank you again. I will check this out over the weekend and report back my findings. Thank you