Very harsh gearchange

[BenzComander]

Recently, the gearchange on our W210 E320 petrol has become very harsh. If, while driving you put your foot down to overtake, the next gear is selected with a real bang through the car. If you accelerate gently then the gear change is smooth.

Also, when coming to a halt, it is noticeable that when stationary the car selects bottom gear with a thump through the car.

Can anybody advise please?

 

[Dieselman]

First stop would be ATF change, then MAF.

After that it's a gearbox fault.

 

[BlackC55]

I suspect a speed sensor problem or the box is on the way out. Check the atf level (first port of call)

I suspect a fault has been logged in the gearbox control unit also.

 

[BenzComander]

Just spent the last four hours on the side of the M25!! No drive to the wheels, no gears at all

Strange thing was car rolled while in park with the handbrake off??

Any suggestions?

 

[Dieselman]

It shouldn't be able to roll in Park as that is the last thing in the back end of the gearbox. Maybe the connection to the propshaft has gone, possibly the bolts have fallen out.
That would explain the banging shifts as well.

 

[BenzComander]

Yes, it's in with Chris Grey now, and he said that should not happen.

Really hoping it is something simple, or the old girl may have to take a bullet!!

 

[BenzComander]

More info, car is definitely selecting a gear, as the revs drop when put in drive. But no forward motion, any further ideas?

 

[Dieselman]

It has to be the output shaft gone kaput..

 

[BlackC55]

If they remove the sump pan and have a look for swarf this will give a good indication of 'box condition.

I hate to say it but it sounds terminal.....

 

[BenzComander]

If they remove the sump pan and have a look for swarf this will give a good indication of 'box condition.

I hate to say it but it sounds terminal.....

 

[diy_dan]

Yes, it's in with Chris Grey now, and he said that should not happen.

Really hoping it is something simple, or the old girl may have to take a bullet!!

rear driveshaft snapped?

 

[BenzComander]

Quick update, just got the car back, and it was the output shaft flange that had come undone!! Mullered the flange, so new one fitted with new nut and all is well again.

Well almost! Symptoms are still apparent when coming to a stop of the car selecting bottom gear two or three seconds after stopping. Any ideas, have been told it may be throttle position sensor fault, confusing the gearbox

 

[c240yaz]

Sounds like your original output shaft problem has transmitted the wear either to the front or the rear through the same drive train line. Most likely rearwards. Could it be prop or diff input splines ?

 

[Amphiscian]

Talk to an autobox specialist. There's plenty of adjustments can be made to affect the quality of shift. Try Bill at BK Transmissions in Overton tel.01256 771577, not a million miles from you, either. Charming man and endlessly helpful. Just did a setup on my old CE with tact and expertise after a headgasket change, when everything goes a bit out of line. Not your situation, I know, but worth a call? (Usual disclaimer: Satisfied customer is all.)

 

[BenzComander]

Another update!! Gearbox now much better

Above symptoms have now gone, gearchange is smooth, with no thumping when you come to a stop??

I know these box's adapt, and have put about 300 miles on it since the repair. Could it have reset itself to normal after it was getting bad signals because the output flange was coming undone??

 

[Dieselman]

Suppose it could be as the speed sensor would be reading incorrect speeds.

Interesting post though. Olly might like to read this.

 

[BlackC55]

MMMM just have.

I think my problem is a speed sensor one.

 

[BenzComander]

Just been down the shops, and got to say the car is transformed!! Smooth changes, both up and down, no catching the box out with quick throttle movement, fantastic.

Not sure if this is linked, but my mysterious misfire is gone as well???

 

[BlackC55]

I was just reading your missfire post.

It sounds just like there is water in the fuel rail.

Your engine has no fuel return and water can build up inside it. The best solutuion is to drain the rail and see what comes out.

 

[BenzComander]

I was just reading your missfire post.

It sounds just like there is water in the fuel rail.

Your engine has no fuel return and water can build up inside it. The best solutuion is to drain the rail and see what comes out.

Thanks, but along with the gearbox problem, the missfire seems to have gone