722.6 TC lock-up disable!!

[AdamG]

Sorry I should say I've had the spring kit fitted by the professionals

I do get TC drag when cold but none of the other symptoms.

One of the reasons I went that route was a post I read about Sprinters vibrating on gearchange where the only solution was the lockup clutch plate spring kit. Also I think the later 7G plus boxes' lockup clutches are mechanically spaced i.e. do not rely on fluid pressure to release. To be honest I'm trying everything now

I've had my gearbox in pieces and it all looks in very good condition. The only possible issue is a little wear on the pump bushing. I recon that was where the gold speckles came from in the pan.

I've attached a photo of me changing the rear stator bearing.

 

[Frontstep]

Thats a neat roll of paper

 

[stumo]

The RSN is the same symptom we see with glycol contamination, and very familiar/diagnostic to those working with such cars.

Now thats interesting. The sprinter usually doesn't do RSN on fresh 236.14/236.10 fluid until theres about 10,000 - 15,000km on the fluid. Then it shows up and gets worse and worse until the next schwduled fluid change (50,000km iirc), rinse repeat.

I read about the sprinter lockup in low gears in the NAFTA sprinter service manual, iirc its every gear except 1st. And sure enough you can feel it locking the gears when driving, its quite an aggressive jolt because it tends to do it on higher load, not on lighter load like you'd do in a manual. You can also feel it on downshifts too - if you are pulling strongly up a hill and then ease off as you crest it, the TC actually unlocks as you back off the throttle, and hence engine revs actually rise a little. This is notable because its kind of the opposite of what you'd expect.

 

[AdamG]

Thats a neat roll of paper

If you are referring to the blue paper it is Scott garage shop towels from Halfords. They are very good. Much much better than kitchen cloth and produce less lint which was the main reason for using them.

Adam

 

[Alex Crow]

Now thats interesting. The sprinter usually doesn't do RSN on fresh 236.14/236.10 fluid until theres about 10,000 - 15,000km on the fluid. Then it shows up and gets worse and worse until the next schwduled fluid change (50,000km iirc), rinse repeat.

I read about the sprinter lockup in low gears in the NAFTA sprinter service manual, iirc its every gear except 1st. And sure enough you can feel it locking the gears when driving, its quite an aggressive jolt because it tends to do it on higher load, not on lighter load like you'd do in a manual. You can also feel it on downshifts too - if you are pulling strongly up a hill and then ease off as you crest it, the TC actually unlocks as you back off the throttle, and hence engine revs actually rise a little. This is notable because its kind of the opposite of what you'd expect.

Does anyone ever try using the Dr Tanny Shudder Fixx on the Sprinters I wonder?

 

[LordPhoenix]

Sorry to bump this old thread. I have the same issue. Just considering blocking the solenoid.

However. The hole is so small on the top. Exactly what size pop rivet fits.

Thanks

 

[Bela B Rethi]

Had an old CLK240 in the other day, with TC lockup issues.
This car had a Behr rad, with no reason to suspect glycol problems.
On roadtest it seems to be a valve body fault (you get a good idea, having driven so many with the TC problems).
Quoted for a new valve body, fluid/filter change etc, but customer hard up, and car not worth all that much.
So we turned off the TC to show the customer how we know what is playing up, and customer thinks it is perfect, happy with the drive of the car.

Thus we elected to go for a TC lock-up delete, as is popular on some Sprinters with the 722.6
Car now drives very well, with no fault codes and no gearchange issues. Obviously, we do see the revs climb a little more with throttle openings, and supposedly fuel consumption is affected slightly, but customer very happy.

Anyone else tried it?

Hello Alex,

I’ve found a very interesting post of yours deleting the TC clutch on a MB with the 722.6 transmission.
My car is a W211 2.1CDI engine from 2007.
I did have a similar issue at the beginning of winter, when I first started the car in the morning the TC lockup was engaging very harsh and making a shuddering noise until the transmission warm up a bit. After a long research I did replace myself the TCC solenoid on the valve body which solved the problem, but I performed a reset of the adaptation values on the TC lockup and transmission.
I need to mention that I’ve used Delphi diagnostic tool as I do not have a Star. After resetting the adaptation values I did perform the torque converter adaptation via torque ranges. The gear changes and TC lockup were working fine ONLY with a small issue...When driving uphill with very light throttle in the 2nd gear around 1800-1900rpm, I press the accelerator half inch to increase speed, the car suddenly changes into 3rd and that shudder appears again until the speed is increased; or it jumps back to the 2nd gear.
I guess the TC lockup clutch is poorly adapted or I might have a small issue with it.
I live in London but I’m keen to pay a visit to your garage to fix this problem. I am thinking to try doing a proper adaptation or a permanent delete of the TC lockup clutch. Can this porcedure cause any harm to the transmission? I drive mostly in town during the week and doing longer journeys (200-300mls) on weekends. Can the transmission excessively heat up? I couldn’t find any answers on this, so I thought asking a person who already done it.

Looking forward hearing back from you.

Regards,
Bela