Shifting on the second gear

[Maxxximus]

Hello everyone!
My question is ... My E420 shifts from first to second gear at 4500 rpm.
From the second to the third, it revs up to 6000, as well as from the third to the fourth.
Does anybody knows what the problem is? Why is the car not going up to 6 thousand rpm in first gear?

 

[gsxr]

Assuming you are at full throttle... the kickdown solenoid is not engaged. Either the electric signal is not present, or the solenoid/magnet is not working if there is +12v present.

What happens if you select "B" position and accelerate at light throttle? Will it stay in 1st gear until you move the shift lever out of "B"?

 

[Maxxximus]

Assuming you are at full throttle... the kickdown solenoid is not engaged. Either the electric signal is not present, or the solenoid/magnet is not working if there is +12v present.

What happens if you select "B" position and accelerate at light throttle? Will it stay in 1st gear until you move the shift lever out of "B"?

Never tried driving with the lever in "B" position.

 

[Maxxximus]

Assuming you are at full throttle... the kickdown solenoid is not engaged. Either the electric signal is not present, or the solenoid/magnet is not working if there is +12v present.

What happens if you select "B" position and accelerate at light throttle? Will it stay in 1st gear until you move the shift lever out of "B"?

When driving on the fourth and third gear kickdown works perfectly.

 

[gsxr]

Never tried driving with the lever in "B" position.

Try what I described above.

When driving on the fourth and third gear kickdown works perfectly.

With the electrical kickdown solenoid not functioning, you will still get 6000rpm WOT upshifts from 2-3 and 3-4 based on the Bowden / control pressure cable signal.

You were asking specifically about 1-2 WOT upshift not being about 6000rpm. That requires the electrical signal.

 

[Maxxximus]

Try what I described above.



With the electrical kickdown solenoid not functioning, you will still get 6000rpm WOT upshifts from 2-3 and 3-4 based on the Bowden / control pressure cable signal.

You were asking specifically about 1-2 WOT upshift not being about 6000rpm. That requires the electrical signal.

Thanks a lot,buddy

 

[B16 NYK]

I've noticed this exact same thing on many of the 560 W126s I've driven including my own. It seems that the (Euro) models from approx. 1989 will go to 6000rpm in first but the earlier cars will shift at about 4800 and then 6000rpm therafter; 'B' making no difference on full throttle. I always suspected the valve body was different on the later cars

 

[gsxr]

I'm not sure about the 126 transmissions, but for the W124 with M119, it should upshift from 1-2 at 6000rpm at WOT, if everything is working correctly. With the kickdown solenoid not engaged, 1-2 upshift will be somewhere between 4500-5000rpm instead of 6000.

 

[Maxxximus]

Assuming you are at full throttle... the kickdown solenoid is not engaged. Either the electric signal is not present, or the solenoid/magnet is not working if there is +12v present.

What happens if you select "B" position and accelerate at light throttle? Will it stay in 1st gear until you move the shift lever out of "B"?

Hi,
Today was in my workshop. First of all checked, if the electric signal is present - everything fine with it. Then changed kickdown solenoid - nothing has changed.A car shifts on the second gear at 4500 r.p.m.
Speaking about acceleration lightly in "B" position - the car goes to 5200r.p.m and does not shift(make higher revs doesn't have sense).

 

[gsxr]

Hi,
Today was in my workshop. First of all checked, if the electric signal is present - everything fine with it. Then changed kickdown solenoid - nothing has changed.A car shifts on the second gear at 4500 r.p.m.
Speaking about acceleration lightly in "B" position - the car goes to 5200r.p.m and does not shift(make higher revs doesn't have sense).

Since the car goes to 5200r.p.m with acceleration lightly in "B" position - that indicates the solenoid is working, and the "B" position switch is working.

However, you could still have a faulty kickdown switch behind the pedal. Have you checked this?

 

[Maxxximus]

Since the car goes to 5200r.p.m with acceleration lightly in "B" position - that indicates the solenoid is working, and the "B" position switch is working.

However, you could still have a faulty kickdown switch behind the pedal. Have you checked this?



View attachment 126862

But kickdown works perfectly on other gears...
How is it possible?

 

[gsxr]

But kickdown works perfectly on other gears...
How is it possible?

Because the other gears are basing the upshift on the control pressure cable alone.

I've tested this on my cars in the past. With the kickdown switch not working, the 1-2 upshift is at at a lower RPM, as described in post #8 above... but 2-3 and 3-4 will still be at redline. If you study the FSM charts for upshift MPH/KPH at full throttle, with/without kickdown, the 1-2 shifts are considerably lower without kickdown, vs the 2-3 and 3-4. It's how the valvebody is designed to work.

 

[Maxxximus]

Because the other gears are basing the upshift on the control pressure cable alone.

I've tested this on my cars in the past. With the kickdown switch not working, the 1-2 upshift is at at a lower RPM, as described in post #8 above... but 2-3 and 3-4 will still be at redline. If you study the FSM charts for upshift MPH/KPH at full throttle, with/without kickdown, the 1-2 shifts are considerably lower without kickdown, vs the 2-3 and 3-4. It's how the valvebody is designed to work.

An interesting thought occurred to me.
My car does not have an ASR system. Perhaps that is why it does not spin up to 6000 rpm in first gear? Could this be the reason?

 

[Maxxximus]

Since the car goes to 5200r.p.m with acceleration lightly in "B" position - that indicates the solenoid is working, and the "B" position switch is working.

However, you could still have a faulty kickdown switch behind the pedal. Have you checked this?



View attachment 126862

today we checked if there is power to the kick down solenoid. When I pressed the kick down switch, it gave a signal to the solenoid, so, the switch is performing its function. Or am I misunderstanding something?

 

[gsxr]

An interesting thought occurred to me.
My car does not have an ASR system. Perhaps that is why it does not spin up to 6000 rpm in first gear? Could this be the reason?

No, the transmission shifting is the same with or without ASR.

today we checked if there is power to the kick down solenoid. When I pressed the kick down switch, it gave a signal to the solenoid, so, the switch is performing its function. Or am I misunderstanding something?

What you describe should be an accurate test. If you pressed the kickdown switch with the ignition on, and there was +12V at the solenoid, it sounds like that is working correctly.

At this point, I can't explain why it isn't working right. Video below is from an E500 but the E420 should shift exactly the same way at full throttle. Ignore that the tach shows ~6300rpm, the tachometer reads higher than actual engine RPM. The upshifts are right around 6000rpm in each gear.