S65 722.6 gearbox issue?

[alexanderfoti]

Fluid wasn't too bad. The magnet had the usual grey ish fine filings but no big bits or copper/brass colours.

There wasn't much oil in or around the bushing but I guess the last thing to look at is the tcu.

Where is the thing located in the engine bay or under the passenger floor.

That's a good sign. There was a thread I read somewhere where a guy had similar issues. He dropped the pan and had small bits of copper metal in the sump. He changed the electro plate and all the solenoids and it didnt sort it. He eventually did fix it but I cannot remember where it was!

 

[hoppo]

I've had a hunt right through and I can't find it either.

Where is the tcu located?

 

[alexanderfoti]

I've had a hunt right through and I can't find it either.

Where is the tcu located?

Passenger footwell, under the carpet.

 

[hoppo]

That's the one I thought it was no signs of oil in the plugs there

 

[alexanderfoti]

Are the shifts from 3-4 ok, is just the downshifts?

Does it still go into neutral?

Any chance of looking up the adaption data? the 3/4 shift solenoid is the only one involved in going into and from 4th gear, so I'm not sure how it would only affect one.

B2 clutch is turned off from 3-4 and turned on from 4-3 so the B2 clutch may be where your issue lies.

K3 is turned on going from 3-4 and turned off going from 4-3. This clutch (along with K2) is ones that normally wears on these v12's, but flaring changes and very high fill times are symptomatic of this. Do you have flaring changes on mid to full throttle on 3-4?

 

[hoppo]

It's only on the down shift.
And yeah it still drops to neutral but not as often
The equipment I have can't see fill time etc.

There is no evidence of damage to the clutches in the oil pan. So I hope it's not this.

I'm not sure what you mean by flaring changes?

I think I'll have to get it on star and get a report of the adaptation times etc.

 

[Botus]

flaring = revving up due to slip (inside the box) when going in to the next gear

bad news and will wear things out

 

[V6Matty]

OP I note your just down the road in Leiceter, your welcome to meet up at some point and we can dig through the data with my STAR may just help identify the problem

 

[hoppo]

OP I note your just down the road in Leiceter, your welcome to meet up at some point and we can dig through the data with my STAR may just help identify the problem

That would be amazing. Just let me know when your free. Where abouts are you.

 

[LostKiwi]

Matty is in Newark. I also have Star and am in Daventry.

 

[V6Matty]

With work at the moment it's going to be next weekend before I'm free but could do either Saturday or Sunday morning if you like?

 

[hoppo]

With work at the moment it's going to be next weekend before I'm free but could do either Saturday or Sunday morning if you like?

Sat morning would be perfect. Just let me know when and where and what you favourat drink is.

 

[hoppo]

Update

I had to do a 20 odd mile drive today and the 4 to 3 downshifts got much better. Not perfect but better.

Then the box lost drive again coming off a roundabout.

It sorted it's self the a little later the box dropped into limp mode. Shift indicator showed N but the box was stuck in 3rd and the eml was on.

Stopped and restarted fine again.

Then I started getting "park assist unavailable" every time at low speeds.

So quick plug in and the following codes

Trans

0730 trans has impermissible ratio

0734 the gear is implausible or the trans is slipping (4th)

1731 the gear comparison is negative or the target gear is not reached

Engine

2069
206D fault stored in etu

Parking brake
5829 one or more signals from at is implausible
5831 fault in coms with esp control module

Hopfuly star can shed some more light.

I've also spoken with my local at workshop they have the kit and seemed very knowledge about this transmission. But they can't look till next week.

 

[alexanderfoti]

Update

I had to do a 20 odd mile drive today and the 4 to 3 downshifts got much better. Not perfect but better.

Then the box lost drive again coming off a roundabout.

It sorted it's self the a little later the box dropped into limp mode. Shift indicator showed N but the box was stuck in 3rd and the eml was on.

Stopped and restarted fine again.

Then I started getting "park assist unavailable" every time at low speeds.

So quick plug in and the following codes

Trans

0730 trans has impermissible ratio

0734 the gear is implausible or the trans is slipping (4th)

1731 the gear comparison is negative or the target gear is not reached

Engine

2069
206D fault stored in etu

Parking brake
5829 one or more signals from at is implausible
5831 fault in coms with esp control module

Hopfuly star can shed some more light.

I've also spoken with my local at workshop they have the kit and seemed very knowledge about this transmission. But they can't look till next week.

Shift indicator on the center of the dash on the AMG screen, or shift indicator on the right hand side?

I wonder if you have a dodgy speed sensor causing this.

Although, I would take those code definitions with a pinch of salt as they are not coming from MB kit. I would expect the ESP/ABS control module to have those faults too.

 

[hoppo]

Shift indicator on the amg screen not the one to the right of the Speedo.

 

[alexanderfoti]

Shift indicator on the amg screen not the one to the right of the Speedo.

Ah OK, the latter may have indicated a Selector module fault!

 

[V6Matty]

Sorry hoppo, I missed your reply and your im the other day. Saturday should still be fine, not sure where would be best for meeting but I guess it depends where in Leicester yor moving from, might be easy at somewhere like hobbyhorse roundabout or Leicester forest services?
I'll make sure STAR is all charged and I'll havea flick through the menus this week to familiarise myself better, I'm still getting to know what it can do and where things are in the system

 

[alexanderfoti]

I would say you have either, a failed K3 clutch, or a bad gearbox oil level (roundabout!), if you are 100% sure on the latter, then adaptions will show the former.

Does it loose drive until full throttle, partial throttle or all conditions going from 3-4?

 

[V6Matty]

I would say you have either, a failed K3 clutch, or a bad gearbox oil level (roundabout!), if you are 100% sure on the latter, then adaptions will show the former.

Does it loose drive until full throttle, partial throttle or all conditions going from 3-4?

Any tips on where to go in live data to see these Alex, or would you think check the level and do adaptions and see where he is before delving in further

 

[alexanderfoti]

Any tips on where to go in live data to see these Alex, or would you think check the level and do adaptions and see where he is before delving in further

It will be, Drive > Transmission > Adaptions > Display and reset all adaption data >

Then F2 to go through all the data series, you will get to the page like this:

Look at "Filling time of clutch K3 when switching on given in cycles" - If its above 10, it indicates its worn, if its above 15 it indicates its REALLY worn and probably has a mechanic fault.

Clutch K3 response time adaption data is
1. high load, low rpm adaption time
2. low load, low rpm adaption time
3. negative load, low rpm adaption time.

If any of these are above 210 ish, you will see flared changes at all times, and also indicate a worn or faulty k3 clutch.

Check the level when hot and in park before all this though