That tends to eliminate the cable from consideration of the problem.

My thought is that the kickdown solenoid in the transmission might have stuck in the closed position. The problem seemed to occur right after the kickdown switch engaged the transmission and is ongoing since that event.

I'm not knowledgeable of how that solenoid works in the trans, but it's my first suspicion from the data presented.

Is there a real solenoid in the trans? I haven't found it in my ATSG service manual yet.

I haven't found a mention of where the connection actually is.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

Fixed it!!!!

Here's what happened...

I made sure the bowden cable was working smoothly. I was able to grasp the cable and push it in and pull it out to it's extent, about 1-1/2 to 2 inches a number of times. I left it connected, with slight slack.

I removed the floor pad and verified the kickdown switch was operating correctly. Normally open and a short when pressed down. I connected the switch back to the system.

I test drove the car and the trans was still not shifting. While still in gear and moving (1st gear, or does it start in second?), I used my left foot and pressed on the kickdown switch several times, maybe half a dozen. This did not of course make the car downshift as I the accelerator pedal was not at WOT. But the car does now shift correctly.

I think there is a solenoid in the trans somewhere and it was stuck. Operating the solenoid several times more, got it unstuck.

The trans was rebuilt in 2003 and not installed and filled with fluid until this year. Perhaps it corroded slightly if not well lubricated before installation.

In any case, if others are having the problem of only shifting at 4500 RPM and above, try operating the kickdown switch a buch of times (key on of course). It may free it up. If you're worried about it happening again, then disconnect it afterward.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

Maybe this will be of some help. I was just arriving in Austin, TX from NC (3 day trip) when my 87 300SDL started acting up just as yours, not wanting to shift unless rpms were really high, BENS of Austin were the BEST! 1. Aux fan blown fuse. 2. Clutch fan - bad clutch. So trans was overheating (july in Austin). Had trans serviced completely and R&R fans. Drove back to NC in two days.. love this benz.

My problem is not overheating, but maybe some others may have that problem.

My car does this from a cold start.

I found a mention of the kickdown solenoid. In the ATSG manual, page 72-73, the kickdown solenoid is facing the rear of the car, right next to the output shaft. It is on the passenger side, facing the ear for the exhaust pipe hanger. Tighten to 20-Nm.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

Interesting new reading about the kickdown. I have a few updates to report!

First of all, I drove the car the other day and it shifted fine, like nothing is going on. But I will say the day before it was dragging off the line, I figured it was lack of turbo due to the fact that I have all my vacuum lines disconnected etc. So I got irritated and buried the pedal, low and behold it downshifted and started moving forward quite easily, I was encouraged so I did it a few more times...same result. After reading the latest posts I think I may have an internal solenoid problem. I will keep you updated.

Secondly, there is a rattle, sort of tinny, like someone is rattling marbles in a tin can, coming from underneath the car upon acceleration and up through the gears. It seems to disappear once up to cruising speed. It is not there at idle nor when parked motor revved. It almost sounds like I left a wrench somewhere and it is bouncing around underneath..I searched high and low for anything loose, my only conclusion is it is in the transmission and related to my problem, it seemed to appear around the same time the shifting issues cropped up.

My next plan of action is to suck out some old fluid, put in a can of trans-x, run for a day, change the fluid and filter.

Any recommendations on the type of ATF I should put back in? I have been using Valvoline high mileage dex/merc. Should I put Lucas back in or just run straight fluid?