Kick-down

[n/a]

Hello all,
 I am trying to find out about the kick down switch underneath the
accelerater pedel and when it should make contact to kick down
cos mine is missing somthing and there is a gap when floored will not
kick down, what should be pushing on the switch on the floor and
when?

Regards Pagoda Red

red kelly

[Douglas]

I just went through this. In my case, the kickdown solenoid on top of the transmission was frozen from years of inactivity.

I have a related question -- my car now seems to downshift even at high speeds. At what point should it NOT downshift from 4th to 3rd? How fast do you have to be going either in terms of RPMs or MPH/KPH?

Douglas Kim
New York, NY
280 SL #016220

[rwmastel]

Red,
The pedal should contact the kickdown switch on the floor to activate it.  If you can't push the pedal that far to the floor, then check your pedal and linkage adjustments.  Set them to factory default.

Doug,
My auto trans does not shift from 4th to 3rd until I am going very slow, maybe 20mph or so.  I have to be almost stopped to go from 3rd to 2nd.  If I drive the car Monday, I'll document it.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[Cees Klumper]

After I swapped engines last April, the kickdown on my car [which used to require just the right amount of throttle to activate (so it would downshift when I needed it to, and WITHOUT having to press the throttle right to the floor in order to activate the kick-down switch - so basically downshifting due to the extra vacuum applied] behaves very differently, and I did not touch any of the transmission settings, like modulator pressure or length of the control rod on top of the transmission. I just got a vacuum gauge to help in getting it back in shape. My kickdown switch does work, so when I need to shift down, I just floor it briefly. But it should not need it.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[SL113fan]

Having researched this topic using the forum search, I was under the impression that "moderate speed" kickdown should occur only if the kickdown switch is engaged or the gear lever is moved.  Is it fact that these transmissions should kick down (from 4th to 3rd) after partially opening the throttle (at moderate speed)?

[Douglas]

That's not my experience. On my 280SL, it only downshifts when you engage the switch at the bottom of the pedal.

Douglas Kim
New York, NY
280 SL #016220

[J. Huber]

You know, it wasn't until a similar thread on "P113" a year or so back that I even knew my car had the kickdown switch. I quickly went out to determine if it worked... It did! To get to it, I had to literally floor it...

However, I can honestly say that in 20 years of driving my car -- I have never found cause to use it... I never floor it. I do on occaision, down shift, which to me is the simplest way to "step things up a notch..."

James
63 230SL

[Cees Klumper]

Well, as I mentioned, my car would downshift from 4 to 3 (and I believe also from 3 to 2) when I applied the right amount of throttle, but without engaging the kick-down switch. Just like the UP-shift point should depend on how much throttle you apply - again, without engaging the kick-down switch. After I installed the new engine, it does not behave in the same manner, and I am determined to figure out how to get back to the original settings for the transmission.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[Douglas]

I'd like to hear the perspective of other owners on this. Does your automatic SL downshift without flooring it?

For what it's worth, on my 1973 W114 sedan, the car gently downshifts as you come to a stop.

Douglas Kim
New York, NY
280 SL #016220

[J. Huber]

Ahh. I think I understand Cees. Wholly separate from the "kickdown switch" are the downshift points where the car automatically "kicks down" to the lower gear. Mine does this as the speed drops, usually as I pull off throttle and coast. I have no clue how it works but it does happen in certain scenerios. It allows me to resume throttle smoothly with more pep than if it had stayed in 4th... Make sense?

James
63 230SL

[n/a]

Although I have only had my 1966 230 SL for 2 weeks now and it needs some mechanical work, it does gently downshift on its own as I slow to a stop.

[ja17]

Hello,
I believe this data can be found in the BBB, The Technical Data Booklets, and factory transmission manuals. But for all those without:

Selector Lever In 4:
      gas pedal depressed slightly   2nd-3rd............25kph
                                     3rd-4th............45kph              
                                   
                                     3rd-2nd............18kph
                                     4th-3rd............30kph

        full throttle                2nd-3rd...........45kph
                                     3rd-4th..........120kph

                                     3rd-2nd...........18kph
                                     4th-3rd...........30kph

            Kickdown  and hold       1st-2nd..........25kph
                                     2nd-3rd..........75kph
                                     3rd-4th..........120kph

I will try to list the shifting specs for gear lever in position 2 and 3 also soon!



Joe Alexander
Blacklick, Ohio

[Cees Klumper]

James - I am not talking about the downshift points when decellerating, but rather when accellerating. So if I am driving along at, say, 50 MPH in 4th and I need to quickly pass another car. It used to be that I would only need to press the throtle say 2/3 down to the floor (i.e. not against the kick-down switch), and the car would shift from 4 to 3. Like I am used to all modern automatics doing.
I really only first noticed this when I drove someone else's Pagoda about two years ago, and noticed that his car would shift up and down always at the same speeds, irrespective of the throttle position (i.e.: irrespective of the amount of vacuum going into the [modulator?].
I am starting to think that, on many of our cars, the shifting characteristics are out-of-spec without us actually knowing it.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[J. Huber]

Hi Cees. Thanks for yet another clarification. Of course, all this discussion means I have to take a drive as soon as I get off work...

I believe my car does that automatic down shift on acceleration -- but not if I am going more than about 45-50. If I am past that, my car still has some pretty good spunk (lightweight 230 with fairly new engine) but I think it stays in 4th. For example on a freeway at 60 I can gas it and move the RPMs up to get really going -- but all the while staying in 4th.

James
63 230SL

[Douglas]

Joe, that's pretty definitive, being from the BBB and all. To which model W113 do those specs apply?

Douglas Kim
New York, NY
280 SL #016220

[hands_aus]

Hey Cees,
Doesn't your 280sl have a micro switch on the firewall and not the traditional floor mounted KickDown switch?
Maybe that has something to do with the ease of Kick Down of your car??


Bob (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[Cees Klumper]

Hi Bob. The microswitch on my car is in fact mounted on the firewall, rather than on the intake manifold/venturi. However: one shop that worked on it a couple of years ago disconnected it. The car still ran and shifted fine. When I connected it back up, there seemed to be no difference in the performance, so I left it. Now, with the new engine in place (which required me to disconnect the various wires that come from this switch and other leads, then going onto the transmission and other places - the ones that are on the terminal bolted onto the bottom side of the engine oil pan), I cannot get the car to shift right with the switch connected - so it is not connected now, and the car shifts fine, however without the vacuum-induced kickdown action I used to have.
As for a kickdown switch: since I never needed it, I only started looking for / at it recently. It's there and it works: with the ignition on, if I press it, I can hear the 'click' of the solenoid on the transmission. I adjusted the switch point so that, when I need the car to shift down, it works without having to press too hard on the throttle.
One of the problems seems to be that I can only hear the 3-position solenoid on the transmission move into 2, rather than 3 positions. It could be that that shop adjusted the wiring/linkage so that the first position is always engaged, I don't know. I figured this should not be too difficult to work out, especially since all I did was swap engines, labelling the wiring that I disconnected, and I did not touch any of the linkages etc on the transmission. I have kickdown through the switch, but I want my old vacuum-induced kickdown back, since it was so nice to have a speed-combined-with-throttle-pedal-position kickdown!

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[ja17]

Hello Doug,
Those specs are listed for 230, 250, 280 SL's  cars with automatics in the Mercedes Technical Data Booklet 1969 page 275 and 276. It also states that with axle ratios higher and lower than normal will change these shift figures slightly (less than 10%). The booklet also lists the shift points when the selector is in position "3" and "2".

Joe Alexander
Blacklick, Ohio

[Benz Dr.]

A few things about kick down:
It won't kick down above 60 MPH.
Although there are 3 different positions the first one happens as soon as you start the car. If the engine isn't running then you will only get 2 positions - centre and kick down.
After you start the engine it moves to the rear position and very light throttle makes it move to the centre or driving position. All the way to the floor makes it move to the top or kick down position.
The throttle position switch tells the linkage to move to the centre position so you need to have that working. The car will run very poorly if it stays in the rear position.

Daniel G Caron

[n/a]

Hello Cees,
 My switch is on the fire wall too, and it works now, I looked up the
manual and it states the kick-down will only be activated (by pressing the throttle passed max accelerataion) for a quick burst to make the kick-down work. also I detailed the engine bay over the last two weeks,
and also the boot. The bonnet stay was the hardest to fix as it was twisted the wrong way so my friend and I took the bonnet off to remove
it and heat the stay in the vice with the blow torch and bend it the correct way. so it's the correct bend and it has a retaining strap now,
do you know what colour the top of the dip sticks are when new i.e the
engine oil dip stick (when new was red or black?) and Atf trans stick was Red? and the wing nut on the powered steering was not painted? or not? do you know?

Regards Pagoda Red

red kelly

[Cees Klumper]

Hi Red - good to hear you got that switch sorted out.
As for colors, off the top of my head, I think oil dipstick tops were always red, but I could be wrong. On the ATF tops, there are various kinds. The one on my car is just plain metal now, and it does not look like it would have ever been painted or chromated. Then on the later cars they are plastic - I have one engine with I believe a black plastic cap, but recall seeing other color plastic caps as well. As for the wingnut on the power steering reservoir, I don't know whether they were painted/chromated but the ones I have seen are not.
We may come up with something like a reference section on the site with photos of how things should be from an originality standpoint, since this is a topic that comes up so often.

Cees Klumper in Amsterdam
'69 white 280 SL automatic