Transmission Problems? (1 Viewer)

[EuroTrotters]

Hi,

Can Anyone shed any light on this or recommend any auto transmission specialists in the NW please?. Mercedes Sprinter 311CDI Auto (5G-Tronic).

February 2017

I was driving along the motorway, around 60mph, bit of a thud from under my left foot.

From then on, the vehicle has lack of torque or power. At 70mph, the vehicles engine would rev just under 3,000 rpm, 80mph would see just over 3,000 rpm.

After the thud and loss of power. Engine runs at 3,500 rpm at 70 and 80 mph sees it almost red lining at close to 4,000 rpm.

First garage, Independent Mercedes Specialist: Said they could not find any faults. At my request, they carried out a gearbox service at 87,000 miles. When I got it back, the problem remained.

Second Garage, reputable Independent, had the vehicle 10 days, they said they could find no faults.

Third Garage, Another MB Specialist:

They had the vehicle 3 weeks: Said they could not find any faults. But that it required a gearbox service. When I pointed out that this was carried out by Mercedes at 50,000 miles and the above independent a few months before, they said that it had not. Claiming that when this is done, the black sealing cap is snapped off and a red service one is put on. I queried this with Both Enza and the Indy and they are both 100% adamant that it was.
I explained that there is certainly a problem. After further investigation, they said the DPF was blocked, £940 for a replacement plus service £1,575.00. This was carried out and the problem remains.

This garage now say they do not dispute the gearbox services but say there is nothing wrong with the vehicle. As Mercedes say that the vehicle should reach approximately 98-111mph *before cutting out in the ECU, there is.

Comments and opinions welcome.....(Please)?.

TM

Below is a 313CDi at approx 150kph or 93mph
*Depedent on gearbox and final drive.

 

[funflair]

If the revs to speed ratio has suddenly changed could it be something to do with the "lock up" torque converter not locking basically, saying that I would have though that MB Star could diagnose this.

Martin

 

[Pausim]

I am no expert on auto transmission (or much else) but it occurs to me that it might not be going into top gear, hence the high revs. On a VW Golf auto I once owned the top gear belt started to slip. I fixed it by buying a second hand box but did not look inside the defective one. I was told at the time that there are belts within the box which engage the gears (it was news to me) and I’m guessing here but perhaps these can sometimes break as well as slip. If a belt broke under load perhaps it would go with a thud as you describe.

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[davanne]

My late husband used to use Stephenson Transmissions at Preston when he had his garage.
They also solved a problem on our Frankia years ago

 

[Steve N Tracy]

Possible stator in torque converter issue, a simple stall test by a transmission expert should confirm it.

 

[tacr2man]

from auto trans site re 5g tronic
There have been a few complaints about the torque converter clutch not holding correctly. The problem could be caused by a defect clutch inside the torque converter, transmission fluid contamination or a faulty solenoid. The problem is not wide spread but you should be aware of the potential for it to arise.

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[SpeedyDux]

When I had my VW T4 autobox rebuilt, I asked the technician about other Van marques and their autobox problems.

He told me that the Merc Sprinter autobox weak point is the torque converter and he replaces quite a lot of them.

 

[gus-lopez]

If the revs to speed ratio has suddenly changed could it be something to do with the "lock up" torque converter not locking basically, saying that I would have though that MB Star could diagnose this.

Martin

What he said^^^^^Lock up clutch has failed.. revs rise by 500 normally,when it happens.

 

[Parapilot]

Is it full auto, not sprintshift ?

If so the first step (if you have changed transmission fluid) is to check the yellow electric wiring connecter to the gearbox is totally clean and dry (no fluid contamination) - easy 2 minute job.

Next step is to swap the electric plate connector on the valve body (sump removal, but not too hard).

Have they changed the fluid with correct MB spec ? Nothing else will work properly.

Any fault codes on a diagnostics check ?

I'm having major gearbox issues so have learned a lot about them and can recommend some places in the Northwest.

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[EuroTrotters]

Is it full auto, not sprintshift ?

If so the first step (if you have changed transmission fluid) is to check the yellow electric wiring connecter to the gearbox is totally clean and dry (no fluid contamination) - easy 2 minute job.

Next step is to swap the electric plate connector on the valve body (sump removal, but not too hard).

Have they changed the fluid with correct MB spec ? Nothing else will work properly.

Any fault codes on a diagnostics check ?

I'm having major gearbox issues so have learned a lot about them and can recommend some places in the Northwest.

Recommendations welcome. It is a True Auto, would never have another SprintShit and that put me off Robotised Manuals for life.

Thank you all for your replies.

Someone else mentioned viscous coupling ?

 

[Parapilot]

Karl at Merx NW is a very knowledgeable independent ex Mercedes engineer who did a full diagnostic on mine for about £40, and knows all the common problems.

Selector Gearbox in Speke are the ones everyone in the trade uses and recommends -

There are a few other specialists around Aintree, Bootle and Lancashire too, but these are the ones I've used in the past.

 

[tonyidle]

from auto trans site re 5g tronic
There have been a few complaints about the torque converter clutch not holding correctly. The problem could be caused by a defect clutch inside the torque converter, transmission fluid contamination or a faulty solenoid. The problem is not wide spread but you should be aware of the potential for it to arise.

This would be my diagnosis too. The rpm difference suggests that it is the most likely problem as does the 'thud' you describe. Either the torque converter lock-up clutch or the solenoid that causes it to operate. As a long shot it would be worth checking the gearbox electrical connector for damage, corrosion, and full engagement of the two halves.

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